U.S. Department
of Transportation
Federal Aviation
Administration
Subject: Enhanced Flight Vision Systems
Advisory
Circular
Date:
Initiated by: AFS-400
AC No: 90-106A
On January 9, 2004, the FAA published an Enhanced Fight Vision System (EFVS) final rule to
permit an EFVS to be used in lieu of natural vision to descend below decision altitude (DA),
decision height (DH), or minimum descent altitude (MDA) down to 100 feet above the
touchdown zone elevation (TDZE). On (insert date of final rule), the FAA published a final rule
that permitted an EFVS to be used in lieu of natural vision to continue descending from 100 feet
above the TDZE to the runway and land on certain straight-in instrument approach procedures
(IAP). This final rule also permitted certain operators using EFVS-equipped aircraft to dispatch,
release, or takeoff under instrument flight rules and to initiate and continue an approach when the
destination airport weather is below authorized visibility minimums for the runway of intended
landing. Additionally, this final rule established pilot training, recent flight experience, and
proficiency requirements for operators who conduct EFVS operations. As a part of this
regulatory action, the FAA moved Title 14 of the Code of Federal Regulations Part 91,
§ 91.175(l) and (m) to new § 91.176. This advisory circular provides information about the
regulatory requirements for EFVS operations and explains how to obtain authorization to
conduct EFVS operations.
We have made every attempt to write EFVS regulations that are performance-based and not
limited to a specific sensor technology. Such an approach accommodates future growth in realtime sensor technologies used in most EFVS and maximizes the benefits of rapidly evolving IAP
and advanced flight deck technology to increase access and throughput during low-visibility
operations.
John M. Allen
Director, Flight Standards Service
07/26/13
AC 90-106A
Table of Contents
Paragraph
1.
INTRODUCTION. .............................................................................................................................................1
1.1.
1.2.
1.3.
1.4.
1.5.
1.6.
2.
PURPOSE......................................................................................................................................................1
APPLICABILITY. ...........................................................................................................................................1
SCOPE..........................................................................................................................................................1
APPLICABLE REGULATIONS.........................................................................................................................2
APPLICABLE ADVISORY CIRCULARS. ..........................................................................................................3
CANCELLATION. ..........................................................................................................................................3
REGULATORY BACKGROUND, DEFINITIONS, AND LEVELS OF EFVS OPERATIONS ...............4
2.1.
2.2.
2.3.
2.4.
2.5.
3.
Page
EFVS REGULATORY BACKGROUND. ...........................................................................................................4
DEFINITION OF AN EFVS. ............................................................................................................................5
PURPOSE OF AN EFVS. ................................................................................................................................5
DEFINITION OF AN EFVS OPERATION. ........................................................................................................6
LEVELS OF EFVS OPERATION. ....................................................................................................................6
REQUIREMENTS FOR EFVS OPERATIONS ..............................................................................................8
3.1.
3.2.
3.3.
EFVS I OPERATIONS (§ 91.176(B)) .............................................................................................................8
EFVS II OPERATIONS (§ 91.176(A)).......................................................................................................... 18
CONSIDERATIONS FOR EFVS I AND EFVS II OPERATIONS........................................................................ 30
4.
EFVS OPERATIONS WHEN THE REPORTED OR FORECAST VISIBILITY AT THE
DESTINATION AIRPORT IS BELOW AUTHORIZED MINIMUMS .............................................................. 35
4.1.
4.2.
5.
DISPATCH, FLIGHT RELEASE, OR TAKEOFF UNDER IFR WHEN THE REPORTED OR FORECAST VISIBILITY
AT THE DESTINATION AIRPORT IS BELOW AUTHORIZED MINIMUMS. ........................................................ 35
INITIATING OR CONTINUING AN APPROACH WHEN THE DESTINATION AIRPORT VISIBILITY IS BELOW
AUTHORIZED MINIMUMS. ......................................................................................................................... 36
PILOT TRAINING REQUIREMENTS FOR EFVS OPERATIONS ......................................................... 38
5.1.
5.2.
5.3.
5.4.
5.5.
5.6.
5.7.
REGULATORY REQUIREMENT FOR TRAINING. ........................................................................................... 38
INITIAL GROUND TRAINING. ..................................................................................................................... 38
INITIAL FLIGHT TRAINING. ........................................................................................................................ 43
EXCEPTIONS TO THE INITIAL GROUND AND FLIGHT TRAINING REQUIREMENTS OF 14 CFR 61.31(L)(1)
AND (L)(3). ................................................................................................................................................ 46
RECURRENT OR DIFFERENCES TRAINING. ................................................................................................. 48
AIRCRAFT OR FLIGHT SIMULATOR TRAINING............................................................................................ 49
APPROVED EFVS TRAINING PROGRAM. ................................................................................................... 49
6.
RECENT FLIGHT EXPERIENCE AND PROFICIENCY REQUIREMENTS FOR EFVS
OPERATIONS ........................................................................................................................................................... 51
6.1.
6.2.
RECENT FLIGHT EXPERIENCE REQUIREMENTS FOR EFVS OPERATIONS. .................................................. 51
PROFICIENCY CHECK REQUIREMENTS FOR EFVS OPERATIONS. ............................................................... 51
7.
TRAINING FOR DISPATCHERS AND OTHER PERSONS AUTHORIZED TO EXERCISE
OPERATIONAL CONTROL FOR EFVS OPERATIONS ................................................................................... 53
7.1.
7.2.
7.3.
8.
DISPATCH, FLIGHT RELEASE AND FLIGHT FOLLOWING CONSIDERATIONS. ............................................... 53
INITIAL TRAINING FOR DISPATCHERS AND OTHER PERSONS AUTHORIZED TO EXERCISE OPERATIONAL
CONTROL. ................................................................................................................................................. 54
RECURRENT AND DIFFERENCES TRAINING FOR DISPATCH AND FLIGHT RELEASE PERSONNEL. ................ 56
AIRCRAFT QUALIFICATION AND MAINTENANCE PROGRAM REQUIREMENTS ..................... 57
i
07/26/13
8.1.
8.2.
8.3.
8.4.
9.
AC 90-106A
GENERAL................................................................................................................................................... 57
APPLICABILITY. ......................................................................................................................................... 57
AIRCRAFT QUALIFICATION REQUIREMENTS. ............................................................................................. 57
MAINTENANCE PROGRAM. ........................................................................................................................ 58
MAINTENANCE TRAINING FOR EFVS OPERATIONS......................................................................... 60
9.1.
9.2.
10.
GENERAL................................................................................................................................................... 60
MAINTENANCE TRAINING ......................................................................................................................... 60
OPERATIONAL APPROVAL PROCESS FOR EFVS OPERATIONS .................................................... 62
10.1.
10.2.
10.3.
10.4.
10.5.
APPROVAL PROCESS OVERVIEW. .............................................................................................................. 62
AUTHORIZATIONS TO CONDUCT EFVS OPERATIONS. ............................................................................... 63
APPROVAL PROCESS FOR EFVS I OPERATIONS CONDUCTED UNDER PART 91 SUBPART K, 121, 125, OR
135 AND EFVS II OPERATIONS CONDUCTED UNDER PART 91, 121, 125, OR 135. .................................... 65
APPROVAL PROCESS FOR EFVS OPERATIONS CONDUCTED UNDER PART 129. ......................................... 66
WAIVERS TO CONDUCT EFVS OPERATIONS ............................................................................................. 67
APPENDIX A. ACRONYMS AND ABBREVIATIONS ..................................................................................... A-I
APPENDIX B. DEFINITIONS............................................................................................................................... B-I
APPENDIX C. RELATED PUBLICATIONS ...................................................................................................... C-I
C-1. RELATED PUBLICATIONS. .............................................................................................................................. C-I
C-2. HOW TO GET PUBLICATIONS. ....................................................................................................................... C-II
Table of Figures
Figure 1 View during an approach with EFVS (left) and without EFVS (right). (Images courtesy
of NASA Langley Research Center)............................................................................................... 6
Figure 2 EFVS I Operational Concept ............................................................................................ 9
Figure 3 Based on a 17o viewing angle from the cockpit and visibility limitations due to weather,
a pilot might expect to see three or four sequenced flashers and approximately five rows of
approach lights on an ALSF-2 or MALSR lighting system upon arrival at a 200-foot DA with a
flight visibility of RVR 2400. ....................................................................................................... 14
Figure 4 Graphic depiction of what a pilot’s view might be of a MALSR upon arrival at a 200foot DA with a flight visibility of RVR 2400 feet on a 3° glideslope. ......................................... 14
Figure 5 EFVS II Operational Concept ........................................................................................ 20
Figure 6 Use of EFVS on a Precision Approach .......................................................................... 28
Figure 7 Use of EFVS on an Approach With Approved (Published) Vertical Guidance............. 28
Figure 8 Use of EFVS on a Nonprecision Approach .................................................................... 29
Table of Tables
Table 1 Required Visual References............................................................................................ 16
ii
07/26/13
1.
AC 90-106A
Introduction.
Purpose.
This advisory circular (AC) provides information about the operating rules pertaining to
Enhanced Flight Vision System (EFVS) operations and explains how to obtain authorization to
conduct EFVS operations.
Applicability.
This AC applies to all EFVS operations conducted to 100 feet above the touchdown zone
elevation (TDZE) and all EFVS operations conducted to touchdown and rollout under §§ 91.176,
91.189, 121.651, 125.381, and 135.225. This AC also applies to the EFVS provisions of
§§ 121.613, 121.615, 125.361, 125.363, and 135.219 for dispatch, flight release, and takeoff
under Instrument Flight Rules (IFR) when the reported or forecast visibility at the destination
airport is below authorized minimums. In addition, this AC applies to the EFVS provisions of
§§ 121.651, 125.325, 125.381, and 135.225 for initiating or continuing an approach when the
destination airport weather is below authorized visibility minimums for the runway of intended
landing.
Note: The European Aviation Safety Agency (EASA) and other foreign civil
aviation authorities (CAAs) use the term “Enhanced Vision System (EVS)” rather
than the term “Enhanced Flight Vision System (EFVS),” which is used by the
FAA. Both terms refer to a vision system that aviation authorities permit pilots to
use in lieu of natural vision for certain specified operations. You should not
confuse use of the term “EVS” in this context with an EVS that the FAA does not
permit pilots to use in lieu of natural vision to descend below DA/DH or MDA
(see Section 1.3.4).
Scope.
1.3.1. This AC provides the methods, procedures, and practices acceptable to the FAA for
complying with regulations. It is one means, but not the only means of obtaining
authorization to conduct EFVS operations. This AC does not alter regulatory
requirements.
1.3.2. The sections in this AC provide information on the following subject areas:





Regulatory background of EFVS operations;
Levels of EFVS operations which can be currently approved;
The concept of operation associated with each level of EFVS operation;
Regulatory requirements for conducting EFVS operations, including operating;
equipment, training, recent flight experience, proficiency, dispatch and flight release,
and maintenance requirements; and
How to obtain operational approval to conduct EFVS operations.
1.3.3. This AC does not address the use of EFVS for lower than standard takeoff minima.
Section 91.175(f) prescribes civil airport takeoff minimums that are applicable to persons
1
07/26/13
AC 90-106A
conducting operations under Part 121, 125, 129, or 135. Section 91.175(f) makes
provision for the FAA to authorize takeoff minimums other than those specifically
prescribed in that section. Using this provision, lower than standard takeoff minimums
can be authorized for EFVS through existing processes. The FAA, however, has not yet
developed operational requirements or guidance material for this operation. .
1.3.4. This AC does not address the use of EFVS on Category (CAT) II or CAT III Instrument
Approach Procedures (IAPs). While § 91.189 and existing operational approval processes
for CAT II and CAT III operations permit an appropriately certified EFVS to be used as
part of these operations, the FAA has not yet developed operational requirements or
guidance material for using an EFVS for other than situation awareness on a CAT II or
CAT III IAP.
1.3.5. This AC does not address the use of EVS. An EVS is an electronic means to provide the
flightcrew with a sensor-derived or enhanced image of the external scene using
millimeter wave radar, forward-looking infrared (FLIR), or other sensor technologies to
provide a real-time image of the external scene. An EVS is not the same as an EFVS,
however. Unlike an EFVS, an EVS may present a sensor image on a head-down display
(HDD), may not provide the additional flight information or symbology required by
§ 91.176, and may not be able to present the image and flight symbology in the same
scale and alignment as the outside view. It is important to note that an EVS can also use a
head-up display (HUD) as its display element, yet still not meet the regulatory
requirements for an EFVS. While an EVS that uses an HDD or HUD may provide
situation awareness to the pilot, it does not meet the airworthiness standards of Part 23,
25, 27, or 29 for an EFVS, nor does it meet the requirements for EFVS operations under
§§ 91.176, 121.651, 125.381, or 135.225. Consequently, a pilot cannot use an EVS in lieu
of natural vision to descend below DA/DH or MDA under these regulations.
1.3.6. This AC does not address the use of synthetic vision systems (SVS), which use a
computer-generated image of the external scene topography from the perspective of the
flight deck. The synthetic vision image is derived from aircraft attitude, a high-precision
navigation solution, and a database of terrain, obstacles, and relevant cultural features.
Unlike an EFVS, an SVS does not provide an independent, real-time source of forward
scene information. A pilot cannot use a synthetic vision image on an HDD or HUD in
lieu of natural vision to descend below DA/DH or MDA under the regulations.
Applicable Regulations.









Part 1, § 1.1
Part 23, § 23.773(c)
Part 25, § 25.773(e)
Part 27, § 27.773(c)
Part 29, § 29.773(c)
Part 61, §§ 61.31(l), 61.57(h) and (i)
Part 91, §§ 91.175(d)(1), 91.175(e)(1), 91.176, 91.189(d) and (e), 91.905
Part 121, §§ 121.613, 121.615(a), 121.651
Part 125, §§ 125.325, 125.361, 125.363(a), 125.381
2
07/26/13

AC 90-106A
Part 135, §§ 135.219, 135.225
Applicable Advisory Circulars.
1.5.1. Certification criteria for EFVS equipment used to conduct EFVS operations under
§ 91.176 is contained in AC 20-167A, Airworthiness Approval of Enhanced Vision
System, Synthetic Vision System, Combined Vision System, and Enhanced Flight Vision
System Equipment.
1.5.2. Certification criteria for HUDs is contained in AC 25-11A, Change 1, Electronic Flight
Deck Displays.
1.5.3. You can find a list of related or supporting ACs and publications in Appendix 3.
1.5.4. You can order copies of FAA ACs from the United States Department of Transportation,
Subsequent Distribution Office, M-30, Ardmore East Business Center, 3341 Q 75th
Avenue, Landover, MD 20785. You can also obtain copies from the FAA Web site at
www.airweb.faa.gov or www.faa.gov by clicking on the link “Regulatory and Guidance
Library.”
Cancellation.
This AC cancels AC 90-106, Enhanced Flight Vision Systems, dated June 2, 2010.
3
07/26/13
2.
AC 90-106A
Regulatory Background, Definitions, and Levels of EFVS Operations
EFVS Regulatory Background.
2.1.1. The requirements for operating below DA/DH or MDA under instrument flight rules
(IFRs) on instrument approaches to civil airports are contained in §§ 91.175 and
§ 91.176. The FAA has modified these requirements over the years to enable aircraft
operations during reduced visibility conditions while maintaining a high level of safety.
For many years, descent below DA/DH or MDA could only be accomplished using
natural vision (see § 91.175(c)). On January 9, 2004, the FAA published a final rule in
the Federal Register, Enhanced Flight Vision Systems (69 FR 1620), that expanded
operational capability by permitting EFVS to be used in lieu of natural vision to continue
descending below DA/DH or MDA to 100 feet above the TDZE on a straight-in IAP
other than CAT II or CAT III. At and below 100 feet, however, the lights or markings of
the threshold or the lights or markings of the touchdown zone (TDZ) had to be distinctly
visible and identifiable to the pilot using natural vision. A pilot could not continue to
descend below 100 feet by relying solely on the EFVS sensor imagery. The 2004 final
rule also established equipment requirements for EFVS operations and introduced
definitions for EFVS and enhanced flight visibility.
2.1.2. On (insert date of final rule), the FAA published a final rule in the Federal Register,
Revisions to Operational Requirements for the Use of Enhanced Flight Vision Systems
(EFVS) and to Pilot Compartment View Requirements for Vision Systems (__ FR ____),
that further expanded operational capability for EFVS by permitting pilots to use it in lieu
of natural vision to continue descending below 100 feet to touchdown and rollout on a
straight-in precision IAP or an IAP with a published vertical path. This regulatory action
effectively permitted a pilot to use an appropriately certified EFVS in lieu of natural
vision to descend below DA/DH all the way to touchdown and rollout. This final rule
also established equipment requirements for EFVS to touchdown operations and
amended the visual reference requirements for EFVS operations conducted below
DA/DH or MDA down to 100 feet and for EFVS operations conducted below DA/DH to
touchdown and rollout.
2.1.3. In addition to permitting pilots to use EFVS in lieu of natural vision to descend below
DA/DH to touchdown and rollout, the (insert year) final rule contained other amendments
that affect EFVS operations. The FAA amended the definition of EFVS in § 1.1 to more
precisely describe an EFVS and added a definition for EFVS operation. The FAA also
amended the regulations to specify conditions under which an aircraft equipped with
EFVS could be dispatched, released, or permitted to take off under IFR. It also specified
the conditions under which an operator of an EFVS-equipped aircraft may begin an
approach when the weather is reported to be below authorized minimums for the
approach to be flown. The FAA amended Part 61 to require initial training and establish
recent flight experience and proficiency requirements for EFVS operators conducting
approaches using EFVS to ensure that an appropriate level of safety is maintained for all
EFVS operations. As part of this rulemaking action, the FAA also amended the
regulations to permit operators to use an EFVS during CAT II and CAT III approaches.
4
07/26/13
AC 90-106A
2.1.4. Finally, the (insert year) final rule consolidated all of the EFVS requirements in Part 91
into new § 91.176 for organizational and regulatory clarity. The FAA moved and
restructured the regulations for EFVS to 100 feet operations that were located in
§§ 91.175(l) and (m) to § 91.176. Section 91.176(a) contains the new regulations for
EFVS operations to touchdown and rollout, and § 91.176(b) contains the regulations for
EFVS operations that are conducted to 100 feet above the TDZE. Sections 91.176(a) and
(b) are each organized into three main areas – equipment requirements, operating
requirements, and visibility and visual reference requirements.
Definition of an EFVS.
2.2.1. Imaging-sensor technologies can offer significant advantages in both safety and
capability for low-visibility flight operations. 14 CFR part 1, § 1.1 defines an EFVS as
follows: “Enhanced Flight Vision System (EFVS) means an installed aircraft system
which uses an electronic means to provide a display of the forward external scene
topography (the applicable natural or manmade features of a place or region especially in
a way to show their relative positions and elevation) through the use of imaging sensors,
such as forward-looking infrared, millimeter wave radiometry, millimeter wave radar, or
low-light level image intensification. The EFVS sensor imagery and required aircraft
flight information and flight symbology is displayed on a head-up display, or an
equivalent display, so that the imagery and symbology is clearly visible to the pilot flying
in his or her normal position with the line of vision looking forward along the flight path.
An EFVS includes the display element, sensors, computers and power supplies,
indications, and controls.”
Purpose of an EFVS.
2.3.1. An EFVS uses a transparent HUD to combine flight information, flight symbology,
navigation guidance, and a real-time image of the external scene to the pilot on one
display. Imaging sensors, which may be based on FLIR, millimeter wave radiometry,
millimeter wave radar, low-level light intensification, or other real-time imaging
technologies produce a real-time image of the outside scene. The EFVS aligns and scales
the sensor image, along with the aircraft flight information and flight symbology on the
HUD, with the external scene as viewed from the pilot’s perspective through the
windscreen. Depending on atmospheric conditions and the strength of energy emitted
and/or reflected from the outside scene, an EFVS can enable a pilot to see the approach
lights, visual references associated with the runway environment, and other objects or
features that might not be visible using natural vision alone.
2.3.2. During an instrument approach, the purpose of the EFVS image is to enhance the pilot’s
ability to detect and identify the visual references for the runway of intended landing
before they are visible naturally out the windscreen (See Figure 1). Combining the flight
information, navigation guidance, and sensor imagery on a HUD allows the pilot to
remain head up and to continue looking forward along the flight path throughout the
entire approach, landing, and rollout. The overall purpose of an EFVS is to enable a pilot
to use enhanced vision imagery in lieu of natural vision to descend below DA/DH or
MDA, depending on the level of EFVS operation for which the equipment and operator
5
07/26/13
AC 90-106A
are approved. Use of an EFVS may improve safety by enhancing situation and position
awareness, providing visual cues to maintain a stabilized approach, and minimizing
missed approach situations.
2.3.3. In addition to using an EFVS to satisfy the requirements of § 91.176, an EFVS may allow
the pilot to visually detect an obstruction on the runway, such as an aircraft or vehicle,
earlier in the approach, and avoid potential runway incursions during ground operations
in reduced-visibility conditions. Even in situations where the flight visibility under
§ 91.175(c)(2) is sufficient for a pilot to use natural vision to descend below DA/DH or
MDA, an EFVS may provide useful visual cues for enhanced situation awareness.
Figure 1 View during an approach with EFVS (left) and without EFVS (right). (Images courtesy of NASA
Langley Research Center)
Definition of an EFVS Operation.
2.4.1. Section 1.1 defines an EFVS operation as “an operation in which an EFVS is required to
be used to perform an approach or landing, determine enhanced flight visibility, identify
required visual references, or conduct the rollout.” This definition establishes the
conditions under which an EFVS is required to conduct specific operations. While an
EFVS can provide situation awareness in any phase of flight, such use would not
constitute an EFVS operation unless an EFVS is required to be used to perform an
approach or landing in lieu of natural vision, determine enhanced flight visibility, identify
required visual references, or conduct the rollout. A pilot who uses an EFVS to provide
situation awareness on that portion of an IAP down to DA/DH or MDA is not conducting
an EFVS operation. A pilot who uses an EFVS in lieu of natural vision to determine
enhanced flight visibility and to identify the required visual references to descend below
DA/DH or MDA, however, is conducting an EFVS operation. Similarly, a pilot who is
required to use an EFVS for rollout is also conducting an EFVS operation.
Levels of EFVS Operation.
2.5.1. Although the terms “EFVS I” and “EFVS II” are not included in the regulations, the FAA
uses these terms to facilitate the issuance of operational approvals. “EFVS I” refers to
operations that are conducted under the provisions of § 91.176(b), and “EFVS II” refers
6
07/26/13
AC 90-106A
to operations that are conducted under the provisions of § 91.176(a). Accordingly, the
FAA categorizes EFVS operations into two levels as follows:


EFVS I - The installed EFVS has been demonstrated to meet the criteria for
AC 20-167A for EFVS I to be used for instrument approach operations from DA/DH
or MDA down to 100 ft height above the touchdown zone elevation.
EFVS II - The installed EFVS has been demonstrated to meet the criteria for
AC 20-167A for EFVS II to be used for instrument approach and landing operations
that rely on sufficient visibility conditions to enable unaided rollout and to mitigate
for loss of EFVS function. An EFVS that meets the certification criteria for EFVS II
also meets the certification criteria for EFVS I.
Flight Standards (AFS) currently authorizes operators to conduct EFVS II operations
on a straight-in IAP from DA/DH to touchdown down to visibilities as low as a
Runway Visual Range (RVR) of 1000 feet, depending on what an applicant
demonstrated for the EFVS equipment during certification flight test.
2.5.2. It is important to understand that the EFVS regulations contained in § 91.176 do not
specify visibility limitations. Rather, they provide a regulatory framework that enables
the FAA to approve and manage EFVS operations to any visibility, including visibilities
lower than RVR 1000, based on the demonstrated capability of the EFVS equipment and
an operator’s ability to perform the EFVS operations for which they seek approval. This
regulatory framework permits Flight Standards to specify visibility and other operating
conditions and limitations through an operator’s Operations Specification (OpSpec),
Management Specifications (MSpec), or Letter of Authorization (LOA) for EFVS
operations. For certain future EFVS operations, § 91.176(a)(1)(ii) specifies that the
Administrator may require the display of the EFVS sensor imagery, required aircraft
flight information, and flight symbology to be provided to the pilot monitoring on a HUD
or other equivalent display appropriate to the operation being conducted. The FAA made
this regulatory provision to provide a means to respond to future advancements in sensor
or display technology that could operate in very low visibilities.
7
07/26/13
3.
AC 90-106A
Requirements for EFVS Operations
EFVS I Operations (§ 91.176(b))
3.1.1. Operational Concept for EFVS I Operations.
3.1.1.1. You can find the regulations pertaining to EFVS I operations in § 91.176(b). Under
§ 91.175(c) and § 91.176(b), there are two means of operating visually below DA/DH
or MDA in the visual segment of an IAP. One means is by using natural vision under
§ 91.175(c), and the other is by using enhanced vision provided by an EFVS under
§ 91.176(b). An EFVS I operation is an operation in which the pilot uses the enhanced
vision imagery provided by an EFVS in lieu of natural vision to descend below DA/DH
or MDA down to 100 feet above the TDZE on certain IAPs (see Figure 2). To use an
EFVS to descend below DA/DH or MDA, the pilot must meet certain enhanced flight
visibility, visual reference, and operating requirements. At 100 feet above the TDZE
and below, the pilot must transition from enhanced vision to natural vision and must be
able to identify the required visual references using natural vision without reliance on
the EFVS to continue to a landing. In other words, the pilot cannot continue to descend
below 100 feet by relying solely on the EFVS sensor image. The pilot must be able to
identify the required visual references using natural vision or the pilot cannot continue
to descend below 100 feet above the TDZE. The regulations do not require the pilot to
turn off or stow the EFVS to descend below 100 feet above the TDZE, nor do they
require removing the sensor image from the EFVS display to continue to a landing
without reliance on the sensor image. As long as the pilot can see the required visual
references that he or she would normally see through the HUD with natural vision, the
pilot can meet the regulatory requirement. The pilot must base the decision to continue
descending below 100 feet above the TDZE on seeing the required visual references
through the EFVS display by means of natural vision.
3.1.1.2. Section 91.176(b) permits a pilot to use an EFVS to identify the required visual
references and to determine that the enhanced flight visibility provided by the EFVS is
not less than the visibility prescribed in an IAP. Both the visual reference and enhanced
flight visibility requirements must be met before the pilot can descend below DA/DH or
MDA down to 100 feet above the TDZE. This AC discusses enhanced flight visibility
and required visual references associated with EFVS I operations in detail in Sections
3.1.4 and 3.1.5, respectively. In addition to the visual reference and enhanced flight
visibility requirements, the regulations require that the aircraft be continuously in a
position from which a pilot can descend to a landing on the intended runway at a normal
rate of descent using normal maneuvers. The regulations also require that the descent
rate allow touchdown to occur within the touchdown zone of the runway of intended
landing for operations conducted under Part 121 or 135.
3.1.1.3. It is important to understand that using an EFVS does not result in obtaining lower
minima with respect to the visibility specified in the IAP, the DA/DH, or the MDA. An
EFVS simply provides another means, other than that of natural vision, of operating in
the visual segment of an IAP. For example, a pilot who is using an EFVS on a CAT I
Instrument Landing System (ILS) approach that specifies a DA of 200 feet and a
8
07/26/13
AC 90-106A
required visibility of ½ statute mile (SM) must comply with a 200-foot DA and an
enhanced flight visibility of ½ SM, even though the pilot may not have ½ SM mile
flight visibility using natural vision or ½ SM reported visibility. The fact that the pilot
can use an EFVS in lieu of natural vision to descend below the DA in this example
down to 100 feet above the TDZE does not lower the DA or visibility minima specified
in the IAP. The DA is still at 200 feet, and the visibility requirement is still ½ SM. The
difference is whether the pilot assesses the ½ SM visibility prescribed by the IAP using
natural vision or whether the pilot assesses it using an EFVS. People often misinterpret
the benefit of EFVS by thinking it provides a lower decision altitude of 100 feet. This
is not correct. The decision altitude is specified by the IAP the pilot is flying, and it
does not change whether EFVS is used or not. The 100-ft altitude is simply an altitude
along the approach path where a different set of visual references must be seen to
continue descending. In the case of an EFVS I operation, the 100-ft altitude is also
where the pilot must transition to natural vision to identify the required visual
references to continue descending. What EFVS does, is give the pilot another means,
other than using natural vision, to operate below decision altitude. Specifically, it gives
the pilot another means to distinctly see and identify the required visual references
when he or she might not be able to do so using natural vision, and it gives the pilot a
means to see forward along the flightpath the distance required by the IAP -- called
enhanced flight visibility – when the pilot might not be able to do so using natural
vision.
Figure 2 EFVS I Operational Concept
9
07/26/13
AC 90-106A
3.1.2. Equipment Requirements for EFVS I Operations.
3.1.2.1. An EFVS installed on a U.S.-registered aircraft used to conduct an EFVS I operation
must be operable and must be installed in accordance with an FAA type design approval
(a type certificate (TC), amended type certificate (ATC), or supplemental type
certificate (STC)). A field approval is not an acceptable means of EFVS installation for
operations conducted under § 91.176(b). A foreign-registered aircraft used to conduct
EFVS operations that does not have an FAA type design approval must be equipped
with an operable EFVS that otherwise meets the requirements of the U.S. regulations.
3.1.2.2.An EFVS used to conduct EFVS I operations is an installed system that includes:





The display element, which is a HUD or an equivalent display, that presents the
aircraft flight information, features, and characteristics required by the regulations
such that they are clearly visible to the pilot flying in his or her normal position and
line of vision looking forward along the flight path. A head-down display (HDD)
does not meet the regulatory requirement for the display element because it is not a
head-up presentation that permits the pilot to see the EFVS sensor imagery and
aircraft flight symbology while seated in his or her normal position and line of
vision looking forward along the flight path. The regulations do make provision,
however, for head-up presentations, other than a HUD, that the FAA might find
acceptable;
Sensors that provide a real-time image of the forward external scene topography;
Computers and power supplies;
Indications; and
Controls.
3.1.2.3.At a minimum, the EFVS must display the following specific aircraft flight information:









Airspeed;
Vertical speed;
Aircraft attitude;
Heading;
Altitude;
Command guidance as appropriate for the approach to be flown;
Path deviation indications;
Flight path vector (FPV) cue; and
Flight path angle reference cue (FPARC).
10
07/26/13
AC 90-106A
3.1.2.4. The regulations also specify that the EFVS imagery, attitude symbology, FPV, FPARC,
and other cues that are referenced to the imagery and external scene topography must be
conformal. That is, they must be aligned with and scaled to the external view. In
addition, the EFVS must display the FPARC with the pitch scale, and the pilot must be
able to select the appropriate descent angle for the approach. The EFVS must display
the sensor imagery and aircraft flight symbology so that they do not adversely obscure
the pilot’s outside view or field of view through the cockpit window. Finally, the
display characteristics and dynamics must be suitable for manual control of the aircraft.
3.1.2.5. Many EFVS-equipped aircraft provide a display of the sensor imagery to the pilot
monitoring. For EFVS I operations, the aircraft is not required to be equipped with a
display that provides the pilot monitoring with EFVS sensor imagery. If the aircraft is
equipped with a display of sensor imagery for the pilot monitoring, however, it can be
an HDD, a dual EFVS installation, a head-mounted display, or other head up
presentation.
3.1.2.6. A radio altimeter is not required under § 91.176(b) to conduct an EFVS I operation. The
only exception to this would be an EFVS I operation that is conducted on a Special
Authorization (SA) CAT I IAP, which specifies the use of a DH based on radio altitude.
EFVS I operations conducted on a precision IAP or an approach with approved vertical
guidance that utilizes a DA, or a nonprecision instrument approach that utilizes an
MDA, are based on the use of a barometric altimeter.
3.1.2.7. An EFVS that has been certified only for EFVS I operations cannot be used to conduct
EFVS II operations.
3.1.2.8. The Aircraft Flight Manual (AFM) or Aircraft Flight Manual Supplement (AFMS) that
is approved for the aircraft must contain EFVS provisions appropriate to the EFVS
operations to be conducted. An EFVS that the FAA certified after (insert date of final
rule) will contain all of the following statements for EFVS I operations:


“The installed EFVS has been demonstrated to meet the criteria specified in
AC 20-167A for EFVS I to be used for instrument approach operations from
DA/DH or MDA down to 100 ft height above touchdown zone elevation.”
“During certification flight test, the lowest visibility and the maximum final
approach course offset angle at which the installed EFVS was demonstrated to be
used in lieu of natural vision to descend below DA/DH or MDA and complete a
landing in accordance with 14 CFR § 91.176(b) was<insert RVR value or SM
value> and <insert angle in degrees>, respectively.”
3.1.2.9. The AFM/AFMS for an EFVS that was certified before (insert date of final rule) will
contain one of the following statements (or a similar statement) for EFVS I operations:

“The installed <insert manufacturer’s name, make, and model> Enhanced Flight
Vision System complies with AC 20-Vision System performance criteria for
operational credit under 14 CFR § 91.175(l). The demonstrated lateral and vertical
displays meet the criteria for <types of approach>.” or
11
07/26/13
AC 90-106A

“EVS as installed meets the requirements of EFVS (Enhanced Flight Vision
System) as defined in FAR 91.175.”
3.1.2.10. In addition to the statements described in Sections 3.1.2.8 and 3.1.2.9, an AFM/AFMS
may contain additional operating conditions and limitations that are applicable to the
installed EFVS equipment.
3.1.3. Approaches Approved for EFVS I Operations.
3.1.3.1. A pilot may conduct an EFVS I operation on any standard or special IAP that is straightin and that uses published straight-in minima, provided all of the requirements of the
regulations are met (§§ 91.176, 121.651, 125.381, and 135.225, as appropriate). This
includes straight-in precision approaches such as ILS (CAT I, II, and III), microwave
landing system (MLS), Precision Approach Radar (PAR), and ground based
augmentation system [GBAS] landing system (GLS), straight-in approaches with
published vertical guidance such as lateral approach procedures with vertical guidance
(LPV), and lateral navigation/vertical navigation (LNAV/VNAV), and straight-in
nonprecision approaches such as VHF omni-directional range station (VOR),
nondirectional radio beacon (NDB), localizer (LOC), area navigation (RNAV), global
positioning system (GPS), localizer-type directional aid (LDA), simplified directional
facility (SDF), etc.
Note: While § 91.189 and existing operational approval processes for CAT II
and CAT III operations permit an operator to use an appropriately certified
EFVS as part of these operations, the FAA has not yet developed operational
requirements or guidance material for using an EFVS for other than situation
awareness on a CAT II or CAT III IAP.
3.1.3.2. An instrument approach with a circle-to-land maneuver or circle-to-land minimums
does not meet the criteria for straight-in landing minimums. While the regulations do
not prohibit a pilot from using EFVS during any phase of flight, they do prohibit a pilot
from using it in lieu of natural vision to descend below DA/DH or MDA on anything
but a straight-in IAP with straight-in landing minima. A pilot may only use EFVS
during a circle-to-land maneuver provided the visual references required throughout the
circling maneuver are distinctly visible using natural vision. An EFVS may not be used
to satisfy the § 91.175(e)(2) requirement that an identifiable part of the airport be
distinctly visible to the pilot during a circling maneuver at or above MDA or while
descending below MDA from a circling maneuver. The pilot must accomplish this
using natural vision.
3.1.4. Enhanced Flight Visibility Requirements for EFVS I Operations.
3.1.4.1. For EFVS I operations conducted under §§ 91.176, 121.651, 125.381, and 135.225, the
regulations state that no pilot may operate an aircraft at any airport below the authorized
DA/DH or MDA and land unless the pilot determines that the enhanced flight visibility
observed by use of a certified EFVS is not less than the visibility prescribed in the IAP
the pilot is using. The EFVS requirements for enhanced flight visibility under
12
07/26/13
AC 90-106A
§ 91.176(b) are analogous to the flight visibility requirements for natural vision under
§ 91.175(c). To descend below DA/DH or MDA using natural vision under § 91.175(c),
a pilot must make a determination that the flight visibility observed from the cockpit is
not less than what is prescribed in the IAP being flown. The same is true for EFVS.
Under § 91.176(b), a pilot must make a determination that the enhanced flight visibility
observed by using an EFVS is not less than what is prescribed in the IAP being flown
before descending below DA/DH or MDA. Essentially, a pilot must accomplish the
same basic tasks before descending below DA/DH or MDA using EFVS that he or she
would using natural vision to conduct an approach under § 91.175(c) – assess that the
“enhanced” flight visibility is not less than that specified in the IAP the pilot is flying,
identify the required visual references for descent below DA/DH or MDA, assure the
aircraft is continuously in a position to land on the intended runway at a normal rate of
descent using normal maneuvers, and for operations conducted under Part 121 or 135,
assure that the descent rate will allow touchdown to occur within the TDZ.
3.1.4.2. It is important to understand that, for a prescribed visibility value, the “sight picture” of
the relevant visual references that the pilot can see looking forward along the flight path
from the cockpit should be similar whether the pilot is using natural vision or an EFVS.
An EFVS often produces the required enhanced flight visibility when actual reported
visibility is much less. The point of this discussion is that even though actual visibility
may be less, as long as the EFVS provides the required enhanced flight visibility and a
pilot meets all of the other requirements of the regulations, the pilot can continue
descending below DA/DH or MDA using the EFVS. It is important that pilots receive
training on how to assess enhanced flight visibility and what the “sight picture” should
look like. How much of the forward scene, consisting of the approach lighting system
(ALS) or other elements, a pilot sees at DA/DH or MDA under prescribed visibility
conditions depends on individual instrument approach procedure construction
(geometry, threshold crossing height, slant range distance from the cockpit to relevant
visual references, etc.), cockpit cutoff angle, and other relevant factors. As visibility
conditions decrease, the ability of an EFVS to “see through” those conditions may also
decrease. Under low or deteriorating visibility conditions, the ability to properly assess
whether the required enhanced flight visibility exists to continue an approach becomes
even more critical. The purpose of this discussion is not to suggest that a pilot should
count approach lights to determine that the enhanced flight visibility is not less than
what the IAP prescribes. Rather, it is to emphasize that through proper training, a pilot
can learn to form a quick mental representation of what the visual scene should look
like. In this example, the pilot should be able to see slightly further than the 1000-foot
bar on the Medium-intensity Approach Lighting System with Runway Alignment
Indicator Lights (MALSR). If the pilot sees less than this, the required enhanced flight
visibility does not exist for this example approach and the pilot should execute a missed
approach. It is important to remember that the sight picture will vary depending on what
type of ALS is present. Figure 3 and Figure 4 show an example “sight picture” of what
a pilot might expect to see upon arrival at a 200-foot DA with a flight visibility of RVR
2400 feet on a 3-degree glideslope (GS).
13
07/26/13
AC 90-106A
Figure 3 Based on a 17o viewing angle from the cockpit and visibility limitations due to weather, a pilot might
expect to see three or four sequenced flashers and approximately five rows of approach lights on an ALSF-2
or MALSR lighting system upon arrival at a 200-foot DA with a flight visibility of RVR 2400 feet.
Figure 4 Graphic depiction of what a pilot’s view might be of a MALSR upon arrival at a 200-foot DA with a
flight visibility of RVR 2400 feet on a 3° GS.
3.1.4.3. For EFVS I operations, there are different visibility requirements in the part of the
visual segment extending from DA/DH or MDA down to 100 feet above the TDZE than
there are at and below 100 feet above the TDZE. From DA/DH or MDA down to 100
feet, the enhanced flight visibility observed by use of a certified enhanced flight vision
system cannot be less than the visibility prescribed in the instrument approach
procedure being used (§ 91.176(b)(3)(i)). At and below 100 feet above the TDZE,
14
07/26/13
AC 90-106A
however, the enhanced flight visibility requirement no longer applies. At and below 100
feet above the TDZE, a pilot cannot continue to rely on EFVS and must transition to
natural vision to identify the required visual references. At and below 100 feet above
the TDZE, the flight visibility only has to be sufficient for one of the required visual
references specified in § 91.176(b)(3)(iii) to be distinctly visible and identifiable.
3.1.5. Visual Reference Requirements for EFVS I Operations.
3.1.5.1. To descend below DA/DH or MDA, the following visual references specified in
§ 91.176(b)(3)(ii) for the runway of intended landing must be distinctly visible and
identifiable to the pilot using the EFVS:
1. The approach light system (if installed); or
2. The following visual references in both 2(a) AND 2(b) below:
a. The runway threshold, identified by at least one of the following:



The beginning of the runway landing surface;
The threshold lights; or
The runway end identifier lights (REIL).
b. The touchdown zone, identified by at least one of the following:




The runway touchdown zone landing surface;
The touchdown zone lights;
The touchdown zone markings; or
The runway lights.
3.1.5.2. The main differences between the visual reference requirements for an approach using
natural vision and one using EFVS are that, for EFVS operations, the visual glide slope
indicator (VGSI) lights cannot be used as a visual reference, and specific visual
references from both the threshold and TDZ must be distinctly visible and identifiable
to descend from DA/DH or MDA down to 100 feet above the TDZE. Under
§ 91.175(c)(3) where natural vision is used to descend from DA/DH or MDA down to
100 feet above the TDZE, however, only one of the specified visual references must be
visible and identifiable.
3.1.5.3. At 100 feet above the TDZE of the runway of intended landing and below that altitude,
the flight visibility using natural vision must be sufficient for one of the following
visual references specified in § 91.176(b)(3)(iii) to be distinctly visible and identifiable
to the pilot without reliance on the EFVS to continue to a landing:
1. The runway threshold;
2. The lights or markings of the threshold;
3. The runway touchdown zone landing surface; or
15
07/26/13
AC 90-106A
4. The lights or markings of the touchdown zone.
3.1.5.4. As stated in Section 3.1.1.1, above, a pilot cannot continue to descend below 100 feet
by relying solely on the EFVS sensor image to identify the required visual references.
The regulations do not require the pilot to turn off or stow the EFVS, nor do they
require the pilot to remove the sensor image from the EFVS display to continue to a
landing without reliance on the sensor image. As long as the pilot can see the required
visual references that he or she would normally see through the HUD with natural
vision, the regulatory requirement can be met. This enables the pilot to continue to
benefit from the HUD guidance and the additional situation and position awareness
provided by the sensor image on the EFVS display. However, the pilot must base the
decision to continue descending below 100 feet above the TDZE solely on seeing the
required visual references through the EFVS display by means of natural vision. Table 1
contains a list of the visual references the FAA requires the pilot to see to descend
below DA/DH or MDA and 100 feet above the TDZE using both natural vision and
EFVS.
Table 1 Required Visual References
Required Visual References Using
Natural Vision
Descent below DA/DH or MDA under 14
CFR § 91.175 (c) –
At least one of the following references using
natural vision:
Approach light system
Threshold
Threshold markings
Threshold lights
Runway end identifier lights
Visual approach slope indicator
Touchdown zone
Touchdown zone markings
Touchdown zone lights
Runway
Runway markings
Runway lights
Required Visual References Using an
Enhanced Flight Vision System
Descent below DA/DH or MDA under 14 CFR § 91.176 (a)
or (b) –
The following references, using the EFVS:
Approach light system
OR
BOTH paragraphs A and B -A. The runway threshold, identified by at least one of the
following –
-- beginning of the runway landing surface,
-- threshold lights, or
-- runway end identifier lights
AND
B. The touchdown zone, identified by at least one of the
following –
-- runway touchdown zone landing surface,
-- touchdown zone lights,
-- touchdown zone markings, or
-- runway lights.
16
07/26/13
AC 90-106A
At and below 100 feet above the TDZE
under 14 CFR § 91.175 (c) –
At least one of the following visual references:
Approach light system, as long as the red
terminating bars or red side row bars are also
distinctly visible and identifiable
Threshold
Threshold markings
Threshold lights
Runway end identifier lights
Visual approach slope indicator
Touchdown zone
Touchdown zone markings
Touchdown zone lights
Runway
Runway markings
Runway lights
At and below 100 feet above the TDZE under 14 CFR §
91.176 (a) or (b) –
At least one of the following visual references using natural
vision for EFVS I operations or using an EFVS for EFVS II
operations:
The runway threshold,
The lights or markings of the threshold,
The runway touchdown zone landing surface, or
The lights or markings of the touchdown zone.
3.1.6. When to Go Around.
3.1.6.1. During an EFVS I operation, a pilot must initiate a missed approach at or below DA/DH
or MDA whenever:
1. The enhanced flight visibility from DA/DH or MDA down to 100 feet above the
TDZE is less than the visibility minima prescribed for the IAP being used;
2. The required visual references for the runway of intended landing are no longer
distinctly visible and identifiable to the pilot using the EFVS imagery;
3. The aircraft is not continuously in a position from which a pilot can make a descent
to a landing on the intended runway, at a normal rate of descent, using normal
maneuvers;
4. The descent rate of the aircraft would not allow touchdown to occur within the TDZ
of the runway of intended landing for operations conducted under Part 121 or 135;
5. Required equipment malfunctions or becomes inoperative; or
6. An aircraft equipment malfunction, other than required equipment, precludes the
safe continuation of the EFVS I operation.
3.1.7. Other Operating Requirements for EFVS I Operations.
3.1.7.1. To conduct an EFVS I operation, the aircraft must be equipped with, and the pilot flying
must use, an operable EFVS that meets the equipment requirements specified in
§ 91.176(b)(1) and described in Section 3.1.2. While many EFVS-equipped aircraft
provide a display of the sensor imagery to the pilot monitoring, U.S. regulations do not
require it for EFVS I operations. When a display of the sensor imagery is not provided
to the pilot monitoring during EFVS I operations, the FAA considers it sufficient to
17
07/26/13
AC 90-106A
conduct these operations using EFVS-specific procedures and callouts that support crew
coordination and common situation awareness. At 100 feet above the TDZE, both pilots
are relying on natural vision to identify the required visual references to descend to a
landing. If the aircraft is equipped with a display of sensor imagery for the pilot
monitoring, however, an operator should develop procedures for using the display and
the pilot monitoring should receive training on how to use the display.
3.1.7.2. It is important that pilots possess the skills necessary to operate EFVS equipment, that
they receive training, and that the training they receive supports the EFVS operation to
be conducted. As a result, § 91.176(b)(2) specifies that each required pilot flight
crewmember must have adequate knowledge of, and familiarity with, the aircraft, the
EFVS, and the procedures to be used. Each required pilot flight crewmember also must
meet the applicable training, recent flight experience, and proficiency requirements of
§§ 61.31(l), 61.57(h), and 61.57(i) for EFVS operations. These requirements are
described in Sections 5 and 6. Parts 119 and 125 certificate holders must, in addition to
the Part 61 requirements for EFVS operations, meet the applicable training, testing, and
qualification provisions of Parts 121, 125, and 135, as applicable. For foreign persons
conducting EFVS operations in the United States, each required pilot flight
crewmember must meet the applicable training, recent flight experience, and
proficiency requirements for EFVS operations of the civil aviation authority of the State
of the Operator. Sections 5 and 6 address pilot training, recent flight experience, and
proficiency requirements in more detail.
3.1.7.3. The FAA requires an authorization for persons conducting EFVS I operations under
Part 91, subpart K, and Parts 121, 125, 129, and 135. A person who conducts these
operations under Part 91, subpart K must do so in accordance with Management
Specifications (MSpecs) authorizing the use of EFVS. Persons who conduct EFVS I
operations under Part 121, 129, or 135 must do so in accordance with Operations
Specifications (OpSpecs) authorizing the use of EFVS. A person who conducts EFVS I
operations under Part 125 must do so in accordance with OpSpecs authorizing the use
of EFVS, or in the case of a Part 125 Letter of Deviation Authority (LODA) holder, an
LOA for the use of EFVS. The FAA does not require Part 91 operators (other than Part
91, subpart K operators) to obtain an LOA to conduct EFVS I operations. Section 10
addresses authorization and operational approval requirements in more detail.
EFVS II Operations (§ 91.176(a)).
3.2.1. Operational Concept for EFVS II Operations.
3.2.1.1. You can find the regulations pertaining to EFVS II operations in § 91.176(a). Under
§ 91.175(c) and § 91.176(a), there are two means of operating visually below DA/DH in
the visual segment of an IAP. One means is by using natural vision under § 91.175(c),
and the other is by using enhanced vision provided by an EFVS under § 91.176(a). An
EFVS II operation is an operation in which the pilot uses the enhanced vision imagery
provided by an EFVS in lieu of natural vision to descend below DA/DH to touchdown
in reported visibility conditions as low as RVR 1000 feet on certain IAPs (see Figure 5).
18
07/26/13
AC 90-106A
To use an EFVS to descend below DA/DH, the pilot must meet certain enhanced flight
visibility, visual reference, and operating requirements.
3.2.1.2. Section 91.176(a) permits a pilot to use an EFVS to identify the required visual
references and to determine that the enhanced flight visibility provided by the EFVS is
not less than the visibility prescribed in the IAP the pilot is flying. The pilot must meet
both the visual reference and enhanced flight visibility requirements before the pilot can
descend below DA/DH to touchdown. Sections 3.2.4 and 3.2.5 discuss enhanced flight
visibility and required visual references, respectively, for EFVS II operations. In
addition to the visual reference and enhanced flight visibility requirements, the
regulations require that the aircraft be continuously in a position from which a pilot can
descend to a landing on the intended runway at a normal rate of descent using normal
maneuvers. Additionally, for EFVS II operations conducted under Part 91, 121, 125, or
135, the descent rate must allow touchdown to occur within the TDZ of the runway of
intended landing. This differs from the regulatory requirement applicable to EFVS I
operations. Only persons conducting EFVS I operations under Part 121 or 135 are
required to touch down in the TDZ. The FAA considers it prudent to require all
operators who conduct EFVS II operations to land within the TDZ to minimize any
potential for runway overrun in low-visibility conditions.
3.2.1.3. It is important to understand that using an EFVS does not result in obtaining lower
minima with respect to the visibility specified in the IAP or the DA/DH. An EFVS
simply provides another means, other than that of natural vision, of operating in the
visual segment of an IAP. For example, a pilot conducting an EFVS II operation on a
CAT I ILS approach that specifies a DA of 200 feet and a required visibility of ½
statute mile (SM) must comply with a 200-foot DA and an enhanced flight visibility of
½ SM, even though the pilot may not have ½ SM mile flight visibility using natural
vision or ½ SM reported visibility. The fact that the pilot can use an EFVS in lieu of
natural vision to descend below the DA to touchdown when the reported visibility is not
less than RVR 1000 feet does not lower the DA or the visibility minima specified by
the IAP. The DA is still at 200 feet in this example, and the visibility requirement is still
½ SM. The difference is whether the pilot assesses the ½ SM visibility prescribed by the
IAP using natural vision or whether the pilot assesses it using an EFVS. People often
misinterpret the benefit of EFVS by thinking it provides a lower decision altitude of 100
feet. This is not correct. The decision altitude is specified by the IAP the pilot is flying,
and it does not change whether EFVS is used or not. The 100-foot altitude is simply an
altitude along the approach path where a different set of visual references must be seen
to continue descending to touchdown. What EFVS does, is give the pilot another means,
other than using natural vision, to operate below decision altitude. Specifically, it gives
the pilot another means to distinctly see and identify the required visual references
when he or she might not be able to do so using natural vision, and it gives the pilot a
means to see forward along the flightpath the distance required by the IAP -- called
enhanced flight visibility – when the pilot might not be able to do so with natural vision.
3.2.1.4. The FAA authorizes pilots to conduct EFVS II operations from DA/DH to touchdown
down to a reported visibility of RVR 1000 feet. If RVR is not reported, then the lowest
visibility at which a pilot can conduct an EFVS II operation is ¼ SM, since a statute
19
07/26/13
AC 90-106A
mile visibility equivalent to RVR 1000 feet is not reported. The lowest specific
visibility value reported through Automated Surface Observing System (ASOS),
Automated Weather Sensor System (AWSS), or Automated Weather Observing System
(AWOS) is ¼ SM. ASOS, AWSS, and AWOS report visibility values lower than ¼ SM
as “less than ¼ SM,” except at certain locations where the service level provides
additional visibility increments of 1/8, 1/16, and 0.
Figure 5 EFVS II Operational Concept
3.2.2. Equipment Requirements for EFVS II Operations.
3.2.2.1. An EFVS installed on a U.S.–registered aircraft that is used to conduct an EFVS II
operation must be operable and must be installed in accordance with an FAA-type
design approval (a TC, ATC, or STC). A field approval is not an acceptable means of
EFVS installation for operations conducted under § 91.176(a). A foreign-registered
aircraft used to conduct EFVS operations that does not have an FAA-type design
approval must be equipped with an operable EFVS that otherwise meets the
requirements of the U.S. regulations.
3.2.2.2. An EFVS used to conduct EFVS II operations is an installed system that includes:




The display element, which is a HUD or an equivalent display, that presents the
aircraft flight information, features, and characteristics required by the regulations
such that they are clearly visible to the pilot flying in his or her normal position
and line of vision looking forward along the flight path. An HDD does not meet
the regulatory requirement for the display element because it is not a head-up
presentation that permits the pilot to see the EFVS sensor imagery and aircraft
flight symbology while seated in his or her normal position and line of vision
looking forward along the flight path. The regulations do make provision,
however, for head-up presentations, other than a HUD, that the FAA might find
acceptable;
Sensors that provide a real-time image of the forward external scene topography;
Computers and power supplies;
Indications; and
20
07/26/13
AC 90-106A

Controls.
3.2.2.3. At a minimum, the EFVS must display the following specific aircraft flight information:











Airspeed;
Vertical speed;
Aircraft attitude;
Heading;
Altitude;
Command guidance as appropriate for the approach to be flown;
Path deviation indications;
Flight path vector (FPV) cue;
Flight path angle reference cue (FPARC);
Height above ground level such as that provided by a radio altimeter or another
device capable of providing equivalent performance. While the DA and 100-foot
decision points on a precision IAP (other than those where a DH is specified) and
an approach with approved vertical guidance are based upon barometric altitude,
the supplementary information provided by a radio altimeter below 100 feet
contributes to altitude awareness and can be used to help perform the flare and
landing during EFVS II operations conducted to touchdown and rollout. While
this is not a requirement for EFVS I operations, most aircraft used to conduct
EFVS I operations have a radio altimeter; and
Flare prompt or flare guidance, as appropriate, for achieving acceptable
touchdown performance. Each applicant for type design approval would be
required to demonstrate acceptable touchdown performance for their particular
EFVS implementation using either flare prompt or flare guidance. This
requirement is necessary to provide the pilot with additional information to
conduct the flare maneuver during conditions of low visibility typically
encountered during EFVS II operations to touchdown and rollout. Flare prompt
or flare guidance is not required for EFVS I operations; however, an EFVS used
to conduct EFVS I operations must be able to demonstrate acceptable touchdown
performance.
3.2.2.4. When a minimum flightcrew of more than one pilot is required, the aircraft must be
equipped with a display that provides the pilot monitoring with EFVS sensor imagery.
The pilot monitoring display can be a HUD or an HDD. If it is a HUD, it can be a dualEFVS installation, a head mounted display, or other head up presentation the FAA
might find acceptable. If it is an HDD, it must be located within the maximum primary
field of view of the pilot monitoring and any aircraft flight information or symbology
displayed must not adversely obscure the sensor imagery of the runway environment.
While this is a requirement for EFVS II operations, it is not a requirement for EFVS I
operations. Many aircraft used for EFVS I operations, however, provide a display of the
sensor imagery to the pilot monitoring.
3.2.2.5. The regulations also specify that the EFVS imagery, attitude symbology, FPV, FPARC,
and other cues that are referenced to the imagery and external scene topography must be
21
07/26/13
AC 90-106A
conformal. That is, they must be aligned with and scaled to the external view. In
addition, the EFVS must display the FPARC with the pitch scale, and the pilot must be
able to select the appropriate descent angle for the approach. The EFVS must display
the sensor imagery and aircraft flight symbology such that they do not adversely
obscure the pilot’s outside view or field of view through the cockpit window. Finally,
the display characteristics and dynamics must be suitable for manual control of the
aircraft.
3.2.2.6. An EFVS that meets the certification criteria for EFVS II can also be used to conduct
EFVS I operations.
3.2.2.7. The AFM or AFMS that the FAA approved for the aircraft must contain EFVS
provisions appropriate to the EFVS operations to be conducted. An EFVS that the FAA
certified after (insert date of final rule) will contain all of the following statements for
EFVS I operations:


“The installed EFVS has been demonstrated to meet the criteria specified in AC
20-167A for EFVS II to be used for instrument approach and landing operations
that rely on sufficient visibility conditions to enable unaided rollout and to
mitigate for loss of EFVS function. An EFVS that meets the certification criteria
for EFVS II also meets the certification criteria for EFVS I.” and
“During certification flight test, the lowest visibility and the maximum final
approach course offset angle at which the installed EFVS was demonstrated to be
used in lieu of natural vision to descend below DA/DH or MDA and complete a
landing in accordance with 14 CFR § 91.176(b) was<insert RVR value or SM
value> and <insert angle in degrees>, respectively.”
22
07/26/13
AC 90-106A
3.2.2.8. In addition to the statements described in Section 3.2.2.7, an AFM/AFMS may contain
additional operating conditions and limitations that are applicable to the installed EFVS
equipment.
3.2.3. Approaches Approved for EFVS II Operations.
3.2.3.1. A pilot may conduct an EFVS II operation on a straight-in precision IAP or an approach
with approved vertical guidance, provided the pilot meets all of the requirements of the
regulations (§§ 91.176, 121.651, 125.381, and 135.225, as appropriate). To ensure
obstacle clearance and stabilized approach to touchdown, the approach must have
published straight-in minima, a published vertical path, and a published DA, DH, or
alert height (AH). This includes straight-in precision approaches such as ILS (CAT I, II,
and III), MLS, PAR, and GLS, and straight-in approaches with published vertical
guidance such as LPV and LNAV/VNAV. The FAA does not permit EFVS II
operations on nonprecision approaches.
(Note: While § 91.189 and existing operational approval processes for CAT II
and III operations could permit an appropriately certified EFVS to be used as
part of these operations, criteria for using an EFVS for other than situation
awareness on a CAT II or CAT III IAP has not yet been developed.)
3.2.3.2. An instrument approach with a circle-to-land maneuver or circle-to-land minimums
does not meet the criteria for straight-in landing minimums. While the regulations do
not prohibit a pilot from using EFVS during any phase of flight, they do prohibit a pilot
from using it in lieu of natural vision to descend below DA/DH or MDA on anything
but a straight-in IAP with straight-in landing minima. A pilot may only use EFVS
during a circle-to-land maneuver provided the visual references required throughout the
circling maneuver are distinctly visible using natural vision. An EFVS may not be used
to satisfy the § 91.175(e)(2) requirement that an identifiable part of the airport be
distinctly visible to the pilot during a circling maneuver at or above MDA or while
descending below MDA from a circling maneuver. The pilot must accomplish this
using natural vision.
3.2.4. Enhanced Flight Visibility Requirements for EFVS II Operations.
3.2.4.1. For EFVS II operations conducted under §§ 91.176, 121.651, 125.381, and 135.225, the
regulations state that no pilot may operate an aircraft at any airport below the authorized
DA/DH and land unless the pilot determines that the enhanced flight visibility observed
by use of a certified EFVS is not less than the visibility prescribed in the IAP being
used. The EFVS requirements for enhanced flight visibility under § 91.176(a) are
analogous to the flight visibility requirements for natural vision under § 91.175(c). To
descend below DA/DH using natural vision under § 91.175(c), a pilot must make a
determination that the flight visibility observed from the cockpit is not less than what is
prescribed in the IAP the pilot is flying. The same is true for EFVS. Under § 91.176(a),
a pilot must make a determination that the enhanced flight visibility observed by using
an EFVS is not less than what is prescribed in the IAP the pilot is flying before
descending below DA/DH to touchdown. Essentially, a pilot must accomplish the same
23
07/26/13
AC 90-106A
basic tasks before descending below DA/DH using EFVS that he or she would using
natural vision to conduct an approach under § 91.175(c) – assess that the “enhanced”
flight visibility is not less than that specified in the IAP the pilot is flying, identify the
required visual references for descent below DA/DH, assure the aircraft is continuously
in a position to land on the intended runway at a normal rate of descent using normal
maneuvers, and for all operators, assure that the descent rate will allow touchdown to
occur within the TDZ.
3.2.4.2. It is important to understand that, for a prescribed visibility value, the “sight picture” of
the relevant visual references that the pilot can see looking forward along the flight path
from the cockpit should be similar whether the pilot is using natural vision or an EFVS.
An EFVS often produces the enhanced flight visibility prescribed by an IAP when
actual reported visibility is much less. The point of this discussion is that even though
actual visibility may be less, as long as the EFVS provides the required enhanced flight
visibility and a pilot meets all of the other requirements of the regulations, the pilot can
continue descending below DA/DH to touchdown and rollout using the EFVS. It is
important that pilots receive training on how to assess enhanced flight visibility and
what the “sight picture” should look like. How much of the forward scene, consisting of
the ALS or other elements, a pilot sees at DA/DH under prescribed visibility conditions
depends on individual IAP construction (geometry, threshold crossing height, slant
range distance from the cockpit to relevant visual references, etc.), cockpit cutoff angle,
and other relevant factors. As visibility conditions decrease, the ability of an EFVS to
“see through” those conditions may also decrease. Under low or deteriorating visibility
conditions, the ability to properly assess whether the required enhanced flight visibility
exists to continue an approach becomes even more critical. The purpose of this
discussion is not to suggest that a pilot should count approach lights to determine that
the enhanced flight visibility is not less than what the IAP prescribes. Rather, it is to
emphasize that through proper training, a pilot can learn to form a quick mental
representation of what the visual scene should look like. In this example, the pilot
should be able to see slightly further than the 1000-foot bar on the MALSR. If the pilot
sees less than this, the required enhanced flight visibility does not exist for this example
approach and the pilot should execute a missed approach. It is important to remember
that the sight picture will vary depending on what type of approach lighting system is
present, Figure 3 and Figure 4 show an example “sight picture” of what a pilot might
expect to see upon arrival at a 200-foot DA with a flight visibility of RVR 2400 feet on
a 3-degree GS.
3.2.5. Visual Reference Requirements for EFVS II Operations.
3.2.5.1. To descend below DA/DH, the following visual references specified in
§ 91.176(a)(3)(ii) for the runway of intended landing must be distinctly visible and
identifiable to the pilot using the EFVS:
1. The approach light system (if installed); or
2. The following visual references in both 2(a) AND 2(b) below:
24
07/26/13
AC 90-106A
a. The runway threshold, identified by at least one of the following:



The beginning of the runway landing surface;
The threshold lights; or
The runway end identifier lights.
b. The touchdown zone, identified by at least one of the following:




The runway touchdown zone landing surface;
The touchdown zone lights;
The touchdown zone markings; or
The runway lights.
3.2.5.2. The main differences between the visual reference requirements for an approach using
natural vision and one using EFVS are that, for EFVS operations, the VGSI lights
cannot be used as a visual reference, and the pilot must be able to distinctly see and
identify specific visual references from both the threshold and TDZ to descend from
DA/DH or MDA down to 100 feet above the TDZE. Under § 91.175(c)(3) where
natural vision is used to descend from DA/DH or MDA down to 100 feet above the
TDZE, however, the pilot must be able to distinctly see and identify only one of the
specified visual references.
3.2.5.3. At 100 feet above the TDZE of the runway of intended landing and below that altitude,
the pilot using EFVS must be able to distinctly see and identify one of the following
visual references specified in § 91.176(a)(3)(iii) –
1. The runway threshold;
2. The lights or markings of the threshold;
3. The runway touchdown zone landing surface; or
4. The lights or markings of the touchdown zone.
3.2.5.4. A pilot who uses an EFVS that is certified for EFVS II operations can continue to
descend below 100 feet relying solely on the EFVS sensor image to identify the
required visual references provided the enhanced flight visibility requirements for
descending below DA/DH to touchdown and rollout continue to be met and the other
operating requirements of § 91.176(a) are met. In contrast to an EFVS I operation, no
transition to natural vision is required at 100 feet above the TDZE. Table 1 contains a
list of the visual references the pilot must see to descend below DA/DH and 100 feet
above the TDZE using both natural vision and EFVS.
3.2.6. When to Go Around.
3.2.6.1. The regulatory requirements for when a pilot must execute a missed approach under
§ 91.175(c), using natural vision, and § 91.176, using EFVS, are different. While these
two sets of requirements provide a parallel decisionmaking process, the requirements
25
07/26/13
AC 90-106A
for when a pilot must execute a missed approach differ. During an EFVS II operation, a
pilot must initiate a missed approach at or below DA/DH whenever:
1. The reported visibility is less than that specified in the operator’s OpSpec, MSpec,
or LOA;
2. The enhanced flight visibility required to descend below DA/DH is less than the
visibility minima prescribed for the IAP the pilot is flying;
3. The required visual references for the runway of intended landing are no longer
distinctly visible and identifiable to the pilot using the EFVS imagery;
4. The aircraft is not continuously in a position from which a descent to a landing can
be made on the intended runway, at a normal rate of descent, using normal
maneuvers;
5. The descent rate of the aircraft would not allow touchdown to occur within the TDZ
of the runway of intended landing;
6. Required equipment malfunctions or becomes inoperative; or
7. An aircraft equipment malfunction, other than required equipment, precludes the
safe continuation of the EFVS II operation.
3.2.7. Other Operating Requirements for EFVS II Operations.
3.2.7.1. To conduct an EFVS II operation, the aircraft must be equipped with, and the pilot
flying must use, an operable EFVS that meets the equipment requirements specified in
§ 91.176(a)(1). When a minimum flightcrew of more than one pilot is required,
§ 91.176(a)(2)(iii) requires the pilot monitoring to use a display that provides EFVS
sensor imagery to monitor and assess the safe conduct of the approach, landing, and
rollout. During EFVS operations where the pilot flying relies on EFVS from DA/DH
through touchdown and rollout, one cannot assume that the monitoring pilot sees
anything of the outside environment using natural vision. Providing the pilot monitoring
with a display of EFVS sensor imagery supports that pilot’s view of the outside
environment and provides common situation awareness. The pilot monitoring would
carry out his or her normal approach monitoring tasks and use the display of EFVS
sensor imagery to confirm the required visual references, verify visual acquisition of
and alignment with the runway of intended landing, and assist in determining that the
runway is clear of aircraft, vehicles, or other obstructions. Section 3.2.2.4 discusses the
requirements applicable to the pilot monitoring display.
3.2.7.2. It is important that pilots possess the skills necessary to operate EFVS equipment, that
they receive training, and that the training they receive supports the EFVS operation to
be conducted. As a result, § 91.176(a)(2) specifies that each required pilot flight
crewmember must have adequate knowledge of, and familiarity with, the aircraft, the
EFVS, and the procedures to be used. Each required pilot flight crewmember also must
meet the applicable training, recent flight experience, and proficiency requirements of
26
07/26/13
AC 90-106A
§§ 61.31(l), 61.57(h), and 61.57(i) for EFVS operations. Parts 119 and 125 certificate
holders must, in addition to the part 61 requirements for EFVS operations, meet the
applicable training, testing, and qualification provisions of parts 121, 125, and 135, as
applicable. For foreign persons conducting EFVS operations in the United States, each
required pilot flight crewmember must meet the applicable training, recent flight
experience, and proficiency requirements for EFVS operations of the civil aviation
authority of the State of the Operator. Sections 5 and 6 address training, recent flight
experience, and proficiency requirements in more detail.
3.2.7.3. The FAA requires an authorization for all persons conducting EFVS II operations under
Parts 91, 121, 125, 129, and 135. A person who conducts EFVS II operations under Part
91 (other than Part 91, subpart K) must do so in accordance with an LOA for EFVS II
operations. A person conducting EFVS II operations under Part 91, subpart K must
conduct them in accordance with MSpecs authorizing the use of EFVS. Persons who
conduct EFVS II operations under Parts 121, 129, or 135 must do so in accordance with
OpSpecs authorizing the use of EFVS. A person who conducts EFVS II operations
under Part 125 must do so in accordance with OpSpecs authorizing the use of EFVS, or
in the case of a Part 125 LODA holder, an LOA for the use of EFVS. Section 10
addresses authorization and operational approval requirements in more detail.
3.2.8. Example Approaches using EFVS.
3.2.8.1. In the instrument segment of an IAP, which extends down to DA/DH or MDA, a pilot’s
primary reference for maneuvering the aircraft is based on aircraft instruments,
displays, and onboard navigation system. In the instrument segment, an EFVS provides
supporting information and enhances a pilot’s situation awareness by providing a realtime image of the external scene. In the visual segment of an IAP, which extends from
DA/DH or MDA down to the runway, a pilot’s primary reference for maneuvering the
aircraft is based on what he or she sees using natural vision, or in the case of an EFVS
operation, what he or she sees using the EFVS. In the visual segment, the aircraft
instruments, displays, and onboard navigation system provide supporting information.
The visual information provided by an EFVS serves as independent verification of the
position information provided by the aircraft’s displays and systems. The visual
information provided by an EFVS also contributes to assessing the enhanced flight
visibility, helps a pilot align the aircraft with the runway, and provides position, lateral
roll, rate of closure, and distance remaining information.
3.2.8.2. Figure 6 provides an example of how a pilot might use an EFVS on a straight-in
precision approach and includes distances from relevant points along the flight path. For
a CAT I ILS approach, pilots should be aware that the CAT I GS signal is typically only
flight inspected to 100 feet to support published minimums as low as 200 feet above the
threshold. The localizer signal is only flight inspected for CAT I certification purposes
to the missed approach point (MAP). Though many localizers provide acceptable
guidance on the runway, the necessary localizer critical area to ensure signal integrity is
not maintained for CAT I ILS operations. For ILS critical area limitations, pilots should
refer to the Aeronautical Information Manual (AIM) paragraphs in Chapter 1, Section 1,
27
07/26/13
AC 90-106A
titled “Instrument Landing System (ILS),” and the paragraphs in Chapter 2, Section 3,
titled “Mandatory Instruction Signs” and “Location Signs.”
Figure 6 Use of EFVS on a Precision Approach
3.2.8.3. Figure 7 provides an example of how a pilot might use an EFVS on a straight-in
approach with published vertical guidance and includes distances from relevant points
along the flight path. The descent angle shown on the approach plate depicts a
computed vertical path from the Final Approach Fix (FAF) to the runway threshold at
the published threshold crossing height (TCH). By using this published vertical path,
the pilot maintains a stabilized approach that ensures obstacle clearance.
Figure 7 Use of EFVS on an Approach With Approved (Published) Vertical Guidance
28
07/26/13
AC 90-106A
3.2.8.4. Figure 8 provides an example of how a pilot might use an EFVS on a straight-in
nonprecision approach and includes distances from relevant points along the flight path.
When VNAV is not available, a pilot may use other methods for achieving a constant
rate of descent, such as using a self-computed descent rate or using an FPARC and FPV
cue to fly a vertical path that safely clears obstacles. On a nonprecision approach, it is
the pilot’s responsibility to determine a safe path to the runway that clears obstacles. A
pilot who conducts a straight-in nonprecision approach should also verify lateral
alignment with the runway centerline before descending from the MDA because actual
lateral course alignment can vary depending upon facility type, distance from the
facility, or signal variations that can cause an offset from the intended course centerline.
Figure 8 Use of EFVS on a Nonprecision Approach
29
07/26/13
AC 90-106A
Considerations for EFVS I and EFVS II Operations.
3.3.1. EFVS Sensor Performance.
3.3.1.1. During some reduced-visibility conditions, an EFVS can display imagery that may
significantly improve the pilot’s capability to detect approach lights and visual
references of the runway environment and aircraft, vehicles, and animals encroaching
on the landing runway that may not otherwise be visible using natural vision. Pilots
using an EFVS should be careful not to conclude that the flight path is free of hazards
merely because no hazards are visible in the image. In some situations, imaging sensor
performance can be variable and unpredictable. Additionally, to assure a safe obstacle
clearance margin, certain nonprecision instrument approaches may require a pilot to
visually identify known obstacles near the normal approach path when maneuvering in
the visual phase for landing.
3.3.2. Stabilized Approach.
3.3.2.1. Controlled Flight Into Terrain (CFIT) is one of the primary causes of aviation fatal
accidents worldwide. Unstabilized approaches are a key contributor to CFIT events.
Nonprecision approach design may require pilots to perform one or more “step-downs”
during the final approach segment, necessitating multiple thrust, pitch, and altitude
adjustments inside the FAF, thereby increasing pilot workload and the potential for
error during a critical phase of flight. Additionally, on approaches designed without
“step-down” fixes, pilots may descend to the MDA immediately after the FAF. This
practice, commonly referred to as “dive and drive,” can result in extended level flight as
low as 250 feet above the obstacle environment in instrument meteorological conditions
(IMC). The concept of a stabilized approach has been widely promoted for air carrier
operators as a means to help eliminate approach and landing accidents. The goal is to
have the aircraft in the proper landing configuration, at the proper approach speed, and
on the proper flight path before descending below the minimum stabilized approach
height. AC 120-71 considers minimum stabilized approach height to be 1000 feet above
the airport elevation or TDZ Elevation (TDZE) during IMC.
3.3.3. Offset Approaches.
3.3.3.1. Criteria contained in the U.S. Standard for Terminal Instrument Procedures (TERPS)
permits IAPs to be offset by prescribed amounts and still be considered straight-in with
straight-in minima. A non-RNAV nonprecision approach, for example, can be offset up
to 30 degrees from the runway centerline, cross the final approach course up to 5200
feet from the runway threshold, be considered straight-in, and have straight-in minima.
A GPS or RNAV (GPS) approach with LNAV or LNAV/VNAV minimums can be
offset as much as 15 degrees and still be considered straight in, and an ILS or LPV
approach can be offset as much as 3 degrees. Pilots must be especially knowledgeable
of the approach conditions and approach course alignment when considering whether to
rely on EFVS during a nonprecision approach with an offset final approach course.
Depending upon the combination of crosswind correction, approach course offset, and
the lateral field of view provided by a particular EFVS, the required visual references
30
07/26/13
AC 90-106A
may or may not be within the pilot’s view looking through the EFVS display upon
reaching the missed approach point (MAP).
3.3.4. Visual Segment Obstacle Clearance.
3.3.4.1. Precision approaches (e.g., ILS/ MLS) or approaches with computed vertical paths (e.g.,
LNAV/VNAV, LPV, etc.) provide the highest level of safety for both obstacle
clearance and controlled rate of descent. If there is no published vertical guidance to a
runway, the use of the HUD’s FPV and FPARC may assist the pilot in safely flying a
vertical path to clear all obstacles. Since the aircraft is in the visual segment of the
approach, it is incumbent on the pilot to select an appropriate vertical path that ensures
obstacle clearance.
3.3.4.2. The presence of a charted vertical descent angle (VDA) does not guarantee obstacle
protection in the visual segment and does not change any of the requirements for flying
a nonprecision approach. The published VDA is for information only, and is strictly
advisory in nature. There is no implicit additional obstacle protection below the MDA.
3.3.4.3. Additional protection for the visual segment below the MDA is provided if a vertical
descent point (VDP) is published and descent below the MDA is started at or after the
VDP. VDPs provide pilots with a reference for the optimal location to begin descent
from the MDA, based on the designed VDA for the approach procedure, assuming the
required visual references are available. Approaches without VDPs have not been
assessed for terrain or obstacle clearance below the MDA, and may not provide a clear
vertical path to the runway at the normally expected descent angle. Therefore, pilots
must be especially vigilant when descending below the MDA at locations without
VDPs. This does not necessarily prevent flying the normal angle; it only means that
obstacle clearance in the visual segment could be less and pilots should exercise greater
care in looking for and avoiding obstacles in the visual segment.
3.3.4.4. The use of a VGSI can help the pilot determine if the aircraft is in a position to make a
descent from the MDA. However, when the visibility is close to minimums, the VGSI
may not be visible at the start descent point for a normal glide path due to its location
down the runway. Obstacle protection is provided if a VGSI (e.g., VASI or PAPI) is
installed and the aircraft remains on the VGSI glide path angle from the MDA. In some
cases, the VDA and VGSI angles are not coincident and a chart note will indicate that
they are not coincident. In addition, depending on the visibility and the distance the
aircraft is from the VGSI, the color of the VGSI lights might not be seen through the
EFVS or through the HUD (without EFVS) using natural vision. Operators should be
aware that light color can generally be seen through an EFVS when it can be seen
through a HUD with natural vision because the HUD is transparent.
3.3.4.5. Pilots should carefully review approach procedures, prior to initiating an approach, to
identify the optimum position(s), and any unacceptable positions, from which a descent
to landing can be initiated. One can find additional information with respect to obstacle
clearance, VDA, and VDP in the AIM and the Instrument Procedures Handbook.
31
07/26/13
AC 90-106A
3.3.5. Missed Approach Obstacle Clearance.
3.3.5.1. The published missed approach procedure provides obstacle clearance only when the
missed approach is conducted on the missed approach segment from or above the
missed approach point, and assumes a climb rate of 200 ft/NM or higher, as published.
If the aircraft initiates a missed approach at a point other than the missed approach
point, from below MDA or DA/DH, obstacle clearance is not necessarily provided by
following the published missed approach procedure, nor is separation assured from
other air traffic in the vicinity.
3.3.5.2. Prior to initiating an IAP, the pilot should assess the actions to be taken in the event of a
balked (rejected) landing beyond the missed approach point or below the MDA or
DA/DH considering the anticipated weather conditions and available aircraft
performance. Section 91.175(e) authorizes the pilot to fly an appropriate missed
approach procedure that ensures obstruction clearance, but it does not necessarily
consider separation from other air traffic. The pilot must consider other factors such as
the aircraft’s geographical location with respect to the prescribed missed approach
point, direction of flight, and/or minimum turning altitudes in the prescribed missed
approach procedure. The pilot must also consider aircraft performance, visual climb
restrictions, charted obstacles, published obstacle departure procedures, takeoff visual
climb requirements as expressed by nonstandard takeoff minima, other traffic expected
to be in the vicinity, and other factors not specifically addressed by the approach
procedures.
3.3.6. Light Emitting Diode (LED) Lighting.
3.3.6.1. The FAA has replaced incandescent lights with LEDs on certain obstacles and at certain
airport locations throughout the United States. LEDs may also appear in taxiway
centerline lights, taxiway edge lights, low-intensity runway edge lights, beacons, and
obstruction lights. The FAA also has future plans to replace incandescent lamps with
LEDs in MALSRs and green threshold lamps. It is important for pilots to be aware that
certain IR-based EFVS cannot sense, nor do they image, LEDs. The use of LEDs may
diminish the benefits of these EFVS systems, but they do not completely eliminate
them. While the ability to sense approach lights enables EFVS to be used over a wider
range of low-visibility conditions, EFVS also images the runway environment and
runway markings, which are also visual references permitted to be used to descend
below DA/DH or MDA. Future EFVS systems may utilize other sensor technologies
that are not dependent on sensing light output, such as millimeter wave radar, or that are
capable of imaging LEDs by other means. The FAA and industry are working together
to resolve the current issues associated with EFVS and LED interoperability.
3.3.7. Low-Visibility Operations and Surface Movement Guidance and Control System
(LVO/SMGCS) Operations.
3.3.7.1. FAA Order 8000.94, Procedures for Establishing Airport Low-Visibility Operations
and Approval of Low-Visibility Operations/Surface Movement Guidance and Control
System Operations, provides policy for Low-Visibility Operations/Surface Movement
32
07/26/13
AC 90-106A
Guidance and Control System (LVO/SMGCS) operations at Part 139 airports in the
United States. For the purposes of FAA Order 8000.94, LVO means those airport
operations conducted at visibilities of less than RVR 1200. Order 8000.94 provides for
consistent low-visibility (less than RVR 1200) airport operations, establishes standards
for low-visibility airport equipment and enhancements, and implements uniform air
traffic control practices and expectations. Because operating in low-visibility conditions
can be difficult, increased control over aircraft and ground vehicle movement is
essential to protecting the runway from incursions during high-speed LVO. Over the
years, the LVO/SMGCS program has proven to be an effective means of improving
safety by increasing control over aircraft and ground vehicle movement during periods
of low visibility.
3.3.7.2. FAA Order 8000.94 describes two levels of LVO/SMGCS operations. One level begins
at less than RVR 1200 and extends down to RVR 500. The second level begins at less
than RVR 500 and extends down to RVR 300. The 500 RVR value which defines the
transition between the two levels of LVO/SMGCS operations was recently changed
from RVR 600 to RVR 500 by Order 8000.94. As a result, airports are are in the
process of transitioning from RVR 600 to RVR 500. While each airport’s
LVO/SMGCS plan may be different, each airport’s plan will specify their criteria for
entering and exiting LVO/SMGCS operations, the applicable authorized RVR for
ground movement, and the criteria for determining when the airport reaches the lowest
approved LVO/SMGCS level. Based on those criteria, the air traffic control tower or
other appointed air traffic facility specified in the LVO/SMGCS plan will determine
when the airport starts and stops LVO/SMGCS operations.
3.3.7.3. Any use of EFVS and other emerging technologies as a suitable substitute for
established LVO/SMGCS requirements will undergo a specific FAA Headquarters
review and approval to determine whether the proposed technology meets an FAAdetermined equivalent level of safety. If the FAA approves a proposed technology as a
suitable substitute and approves the technology for use at a specific airport, the airport
will incorporate specific provisions for using that technology into their individual
airport LVO/SMGCS plan.
3.3.7.4. Authorizations to conduct EFVS operations will require operators to comply with the
LVO/SMGCS plan at the airports they operate to. An operator who wishes to conduct
an EFVS operation at an airport that has an LVO/SMGCS plan should be aware that
some taxiways and runways may not be available when LVO/SMGCS operations are in
effect if those taxiways and runways are not specified for use in the airport’s
LVO/SMGCS plan. Operators should receive training on the levels of LVO/SMGCS
operations, procedures associated with LVO/SMGCS operations, and the lighting,
marking, and signage requirements associated with those levels. You can find additional
information on LVO/SMGCS operations in FAA Order 8000.94 and AC 120-57,
Surface Movement Guidance and Control System. You can find FAA Airports design
standards, system descriptions, and criteria for Part 139 airports in 150-series ACs.
3.3.8. International Operations.
33
07/26/13
AC 90-106A
3.3.8.1. Currently, most foreign civil aviation authorities (CAAs) require an authorization to
conduct EFVS operations. As a result, a foreign CAA may require a U.S. operator who
wishes to conduct EFVS operations in their country to submit their FAA EFVS
authorization as a condition for the foreign CAA’s approval. The FAA strongly
recommends that operators contact the CAA of each foreign country in which they plan
to conduct EFVS operations to determine the equipment requirements, operational
approval requirements, and requirements for conducting EFVS operations, since those
requirements may be different from those of the United States. Operators of U.S.registered civil aircraft outside of the United States are reminded that they must comply
with § 91.703 and other applicable regulations pertaining to operations that are
conducted outside the United States. This results in complying with the U.S. regulations
and the regulations of the country in which operations are being conducted, whichever
is more restrictive.
34
07/26/13
4.
AC 90-106A
EFVS Operations When the Reported or Forecast Visibility at the Destination
Airport is Below Authorized Minimums
Dispatch, Flight Release, or Takeoff Under IFR When the Reported or Forecast
Visibility at the Destination Airport is Below Authorized Minimums.
4.1.1. The enhanced flight visibility provided by an EFVS enables a pilot to conduct instrument
approach operations safely in lower visibilities than would be possible using natural
vision. Under §§ 121.613, 121.615, 125.361, 125.363, and 135.219, operators of EFVSequipped aircraft are permitted to dispatch or release a flight under Part 121, release a
flight under Part 125, or takeoff under IFR under part 135 when weather reports and
forecasts indicate that weather conditions will be below the minimums authorized for the
approaches the pilot will fly at the estimated time of arrival at the airport or airports to
which dispatched or released. This enables operators to take advantage of the operational
capabilities provided by EFVS and thus improve access to runways, increase service
reliability, and reduce the costs associated with operational delays without compromising
safety. These EFVS provisions apply only to destination airports and do not apply to
alternate airports.
4.1.2. Operators of EFVS-equipped aircraft are authorized to dispatch, flight release, or takeoff
under IFR when the weather conditions at the destination airport are reported or forecast
to be below authorized minimums at the estimated time of arrival through an OpSpec for
EFVS operations conducted under Part 121, 125, or 135, or for Part 125 Letter of
Deviation Authority (LODA) holders, their Letter of Authorization (LOA) for EFVS
operations. The authorization applies to both EFVS I operations conducted under
§ 91.176(b) and EFVS II operations conducted under § 91.176(a). The Principal
Operations Inspector (POI) will develop OpSpec or LOA conditions and limitations
based on the EFVS capabilities that were demonstrated for the aircraft during
certification flight test and documented in the AFM or AFMS, additional data the
operator may have collected through an operational evaluation with respect to the EFVS
sensor’s ability to perform in low-visibility conditions, other rationale the FAA might
find acceptable, and the operator’s ability to perform EFVS operations during the
operational use suitability demonstration (OUSD) period which is part of the operational
approval process. Section 4.2 discusses this in more detail. The purpose of developing
these conditions and limitations is to ensure that an increase in the rate of missed
approaches at the destination airport does not occur during EFVS operations. Because
EFVS performance can vary by sensor technology and design, meteorological conditions,
and other factors, the POI may make adjustments to an operator’s EFVS authorization if
the POI observes an increase in the number of missed approaches during an operator’s
EFVS operations. Managing an authorization in this manner ensures that the FAA is able
to maintain an appropriate level of safety, enables the FAA to effectively respond to new
technology developments, and provides a means to tailor an authorization to fit an
operator’s particular EFVS capabilities.
4.1.3. Operators who plan to conduct these operations should establish operating procedures,
pilot training, and training for dispatchers and persons authorized to exercise operational
control under these conditions. The procedures and training should consider the
35
07/26/13
AC 90-106A
limitations of the EFVS the operator will use and the weather conditions that may exceed
the sensor’s ability to provide the enhanced flight visibility required to complete the
approach and landing. Section 7 contains recommended training for dispatchers and other
persons authorized to exercise operational control. Section 5 contains training
requirements and recommendations for pilots.
Initiating or Continuing an Approach When the Destination Airport Visibility is
Below Authorized Minimums.
4.2.1. Years of EFVS operational experience show that, under certain reduced-visibility
conditions, an EFVS can increase the likelihood that a pilot can successfully complete an
approach and landing. In cases where the visibility is marginal, such as during rapidly
changing weather conditions, or when the reported visibility hovers at or near the
minimum authorized, natural vision may be inadequate for a pilot to detect the required
visual references necessary to complete the approach. EFVS can provide a significant
operational advantage under these circumstances by reducing ground stops, holding
delays, and diversions to an alternate airport.
4.2.2. Under §§ 121.651, 125.325, 125.381, and 135.225, persons conducting operations under
Part 121, 125, or 135 are permitted to initiate or to continue an approach when the
reported visibility is below the authorized minimum visibility prescribed in the IAP the
pilot will be flying, provided the aircraft is equipped with, and a properly trained pilot
uses, an EFVS in accordance with § 91.176. This provision, combined with the dispatch,
flight release, and takeoff provisions discussed in Section 4.1 enables operators of
appropriately equipped EFVS aircraft to take full advantage of the operational
capabilities provided by EFVS without compromising safety.
4.2.3. Operators of EFVS-equipped aircraft are authorized to initiate or to continue an approach
when the reported visibility is below the authorized visibility minimums prescribed in the
IAP through an OpSpec for EFVS operations conducted under Part 121, 125, or 135, or
for Part 125 LODA holders, through their LOA for EFVS operations. The authorization
applies to both EFVS I operations conducted under § 91.176(b) and EFVS II operations
conducted under § 91.176(a).
4.2.4. Operators who plan to conduct EFVS operations should establish pilot procedures and
training for initiating or continuing an approach when the reported visibility is below the
authorized visibility minimums for the approach to be flown. Operators should also
develop procedures and training for dispatchers or persons authorized to exercise
operational control that address initiating or continuing an approach under the EFVS
provisions of §§ 121.651, 125.325, 125.381, and 135.225. These procedures should
consider the limitations of the EFVS the operator will use and the weather conditions that
exceed the sensor’s ability to provide the enhanced flight visibility required to complete
the approach and landing. Section 7 contains recommended training for dispatchers and
persons authorized to exercise operational control, and Section 5 contains required and
recommended training for pilots.
36
07/26/13
AC 90-106A
4.2.5. An operator’s POI will also develop OpSpec conditions and limitations for part 121, 125
or 135 operators or LOA conditions and limitations for part 125 LODA holders for
initiating or continuing an approach when the reported visibility is below the authorized
minimum visibility prescribed in the IAP the pilot will fly. The POI will develop these
conditions and limitations based on the EFVS capabilities that were demonstrated for the
aircraft during certification flight test and documented in the AFM or AFMS, additional
data the operator may have collected through an operational evaluation with respect to
the EFVS sensor’s ability to perform in low-visibility conditions, other rationale the FAA
might find acceptable, and the operator’s ability to perform EFVS operations during the
OUSD period which is part of the operational approval process. The purpose of
developing these conditions and limitations is to ensure that an increase in the rate of
missed approaches at the destination airport does not occur during EFVS operations.
Because EFVS performance can vary by sensor technology and design, meteorological
conditions, and other factors, the POI may make adjustments to an operator’s EFVS
authorization if the POI observes an increase in the number of missed approaches during
an operator’s EFVS operations. As discussed in Section 4.1, managing the authorization
in this manner ensures that the FAA is able to maintain an appropriate level of safety,
enables the FAA to effectively respond to new technology developments, and provides a
means to tailor an authorization to fit an operator’s particular EFVS capabilities.
4.2.6. The operational goal of the EFVS provisions discussed in Sections 4.1 and 4.2 is to
ensure that no more than 5 percent of the approaches conducted using EFVS during a
Part 121, 125, or 135 operation terminates in a missed approach due to the EFVS sensor’s
inability to provide the enhanced flight visibility required to conduct the EFVS operation.
The OUSD will address these and other aspects of an operator’s EFVS operation and
should be conducted over a combination of visibility conditions down to, and including,
the lowest visibility for which the operator is seeking authorization. Inability to achieve
this operational goal during the OUSD period may require an extended OUSD period
while the POI and the operator work together to adjust the authorization so that it
achieves this operational goal. The POI may also apply similar adjustments to an
operator’s authorization for dispatch, flight release, or takeoff under IFR.
4.2.7. Pilots should be aware that some foreign Civil Aviation Authorities (CAAs) permit
operators to deduct 1/3 of the visibility required by an IAP to initiate or continue an
approach using an EFVS when the visibility is reported to be below minimums for the
approach to be flown. For example, if the authorized minimum visibility for an IAP is
RVR 2400 feet, a person operating an EFVS-equipped aircraft could reduce the minimum
visibility required for an approach by 1/3, resulting in an adjusted required minimum
visibility of RVR 1600 feet for the approach. Years of EFVS operations have shown this
to be a valid approach that accommodates most EFVSs currently in use. The FAA
strongly recommends that operators contact the CAA of each foreign country in which
they plan to conduct EFVS operations to determine the requirements for conducting
EFVS operations, since those requirements may be different from those of the United
States.
37
07/26/13
5.
AC 90-106A
Pilot Training Requirements for EFVS Operations
Regulatory Requirement for Training.
5.1.1. A pilot typically conducts EFVS operations in lower than standard visibility conditions.
Over the years, EFVS operations have expanded, increasing the number and mix of
aircraft and operators conducting low-visibility operations at airports throughout the
national airspace system (NAS). Because of the conditions under which a pilot conducts
EFVS operations, it is important that pilots possess the skills necessary to safely and
effectively operate EFVS equipment and that the training they receive supports the EFVS
operation they are conducting.
5.1.2. 14 CFR §§ 91.176(a)(2) and (b)(2) specify that no person may conduct an EFVS
operation in an aircraft, except a military aircraft of the United States, at any airport
below the authorized DA/DH or MDA for EFVS I operations or below DA/DH for EFVS
II operations unless each required pilot flight crewmember has adequate knowledge of,
and familiarity with, the aircraft, the EFVS, and the procedures the pilot will use. The
regulations further state that each required pilot flight crewmember must also meet the
applicable training, recent flight experience and proficiency requirements of §§ 61.31(l),
61.57(h), and 61.57(i) for EFVS operations. In addition to the Part 61 requirements for
EFVS operations, Part 119 and 125 certificate holders must meet the training, testing, and
qualification provisions of Parts 121, 125, and 135, as applicable.
5.1.3. Pilot training shall be comprised of both ground and flight training that meets the
requirements of § 61.31(l). In addition to the training guidance provided in this AC,
operators and training providers should refer to the Flight Standardization Board (FSB)
report for the EFVS-equipped aircraft they will be flying, if such a report is available.
The FAA Aircraft Evaluation Group (AEG) has conducted operational suitability
evaluations of EFVS equipment installed on certain aircraft and has documented through
FSB reports areas for special emphasis in addition to the training, checking, and currency
tasks necessary to safely operate EFVS equipment. You can find FSB reports at
http://fsims.faa.gov/PICResults.aspx?mode=Publication&doctype=FSB%20Reports.
Initial Ground Training.
5.2.1. Sections 61.31(l)(1) and (2) contain the ground training requirements for EFVS I and
EFVS II operations. Under § 61.31(l)(1), any person manipulating the controls of an
aircraft or acting as pilot in command (PIC) of an aircraft during an EFVS operation must
receive ground training from an authorized instructor under a training program approved
by the Administrator. The pilot must obtain a logbook or other endorsement from the
authorized instructor who certifies that he or she satisfactorily completed the ground
training. These ground-training requirements apply to both EFVS I and EFVS II
operations. You can find the definition of an “authorized instructor” in § 61.1(b)(2), and
Section 5.7.1 of this AC explains what a “training program approved by the
Administrator” means.
38
07/26/13
AC 90-106A
5.2.2. The regulations also require any person who serves as a required pilot flight crewmember
during an EFVS II operation, but who does not manipulate the controls or serve as PIC of
that aircraft, to obtain ground training. An authorized instructor must conduct the ground
training, and the ground training must be a training program that is approved by the
Administrator. The required pilot flight crewmember must obtain a logbook or other
endorsement from an authorized instructor who certifies that he or she satisfactorily
completed the ground training.
5.2.3. 14 CFR § 61.31(l)(7) contains certain exceptions to the § 61.31(l)(1) ground training
required to conduct EFVS operations. Section 5.4 explains these exceptions.
5.2.4. Under § 61.31(l), a person who serves as a required pilot flight crewmember during an
EFVS I operation, but who does not manipulate the controls or serve as PIC of that
aircraft, is not required to receive EFVS ground training. Pilots should be aware,
however, that § 61.55 requires any person serving as second-in-command to be familiar
with the operational procedures applicable to an aircraft’s powerplant; equipment and
systems; performance specifications and limitations; normal, abnormal, and emergency
procedures; and flight manual, placards and markings. Part 61 contains the minimum
training requirements for EFVS operations. In addition to the Part 61 requirements, pilots
must also comply with the training provisions of the part under which they conduct flight
operations. Part 121, for example, requires ground and flight training appropriate to the
particular assignment of the pilot flight crewmember.
5.2.5. Ground training must, at a minimum, consist of the following subjects in accordance with
§ 61.31(l)(2):
1. Applicable portions of 14 CFR that relate to EFVS flight operations and limitations,
including AFM limitations;
2. EFVS display, controls, modes, features, symbology, annunciations, and associated
systems and components;
3. EFVS sensor performance, sensor limitations, scene interpretation, visual anomalies,
and other visual effects;
4. Preflight planning and operational considerations associated with using EFVS during
taxi, takeoff, climb, cruise, descent, and landing phases of flight, including the use of
EFVS for instrument approaches, operating below DA/DH or MDA, executing
missed approaches, landing, rollout, and balked landings;
5. Weather associated with low-visibility conditions and its effect on EFVS
performance;
6. Normal, abnormal, emergency, and crew coordination procedures when using EFVS;
and
7. Interpretation of approach and runway lighting systems and their display
characteristics when using an EFVS.
39
07/26/13
AC 90-106A
5.2.6. For certain ground training requirements listed in Section 5.2.5, the FAA recommends
that the ground training cover the following additional subject areas:
1. Applicable portions of 14 CFR that relate to EFVS flight operations and limitations,
including AFM limitations:
a. Regulatory requirements pertinent to the operation being conducted (e.g.,
§§ 61.31(l), 61.57(h) and (i), 91.175(d)(1), 91.175(e)(1), 91.176, 91.189(d),
121.613, 121.615(a), 121.651, 125.325, 125.361, 125.363(a), 125.381, 135.219,
and 135.225). With respect to § 91.189(d), pilots should note that criteria for
using EFVS on CAT II or CAT III approaches has not yet been developed;
b. Enhanced flight visibility requirements (§ 91.176);
c. Visual reference requirements (§ 91.176); and
d. AFM or AFMS limitations.
2. EFVS display, controls, modes, features, symbology, annunciations, and associated
systems and components accompanied by a review of the AFM or AFMS sections
that relate to EFVS, including system description, operating procedures and
limitations:
a. Use of on/off switch “clear” mode;
b. Warm-up requirements, system alignment, display adjustments for brightness and
contrast, contrast differences between daytime and nighttime approach conditions
and display field of view;
c. Understanding and interpreting HUD symbology during EFVS operations;
d. Importance of cross-checking the HUD instrumentation presentations against the
EFVS sensor image:
- Recognition of malfunctions of the navigation equipment;
- Recognition of improper presentation of elements in the visual scene during
the approach;
e. EFVS system limitations, including specific differences between the pilot flying’s
(PF’s) EFVS display and the pilot monitoring’s (PM’s) display, if a PM display is
installed;
f. Proper use of aircraft flight directors and autopilots:
- Autopilot minimum use height considerations;
- Altitude alerting systems during EFVS operations;
g. Use of barometric and/or radio altitude at low heights, including temperature
correction if applicable;
h. Use of the FPV cue and FPARC; and
i. Use and limitations of supplementary or advisory vertical information for
situation awareness below DA/DH or MDA.
3. EFVS sensor performance, sensor limitations, scene interpretation, visual anomalies,
and other visual effects:
a. The specific sensor technology, sensor performance in varying weather
conditions, the sensor’s ability to detect or not detect obstacles in the
40
07/26/13
AC 90-106A
environment, and limitations where sensor performance can be variable and
unpredictable;
b. Effect of crosswinds on EFVS field of view, including the use of caged and
uncaged modes (if applicable) in crosswind conditions;
c. Visual anomalies such as “noise,” “blooming,” parallax, thermal crossover, and
other visual effects; and
d. EFVS sensor limitations associated with specific types of lighting such as
incandescent lamps and LEDs.
4. Preflight planning and operational considerations associated with using EFVS during
taxi, takeoff, climb, cruise, descent, and landing phases of flight, including the use of
EFVS for instrument approaches, operating below DA/DH or MDA, executing
missed approaches, landing, rollout, and balked landings:
a. IAP considerations:
- Use of EFVS on precision approaches, approaches with approved vertical
guidance, and nonprecision approaches;
- Effects of various approach types on aircraft alignment with the runway at
DA/DH or MDA during EFVS operations;
- Understanding of published VDAs, published VDPs, operator-calculated
points for descent below MDA, VGSI angles, and the significance of VDA
and VGSI angles that are not coincident; and
- Obstacle clearance awareness, including the potential for close-in obstacles on
nonprecision approaches with no published VDP.
b. Transition from EFVS imagery to natural vision for detecting required visual
references;
c. Normal and rejected landings, including loss of visual cues from the runway,
TDZ, and rollout area;
d. Detecting runway incursions;
e. Missed approach considerations below DA/DH or MDA and after passing the
MAP, including obstacle clearance awareness;
f. Crew briefings, procedures, callouts, and coordination items for EFVS operations,
including annunciation of published minima and operation below the DA/DH or
MDA:
- Duties of the PF and the PM during EFVS operations, as applicable;
- Flight planning, dispatch, or flight release considerations applicable to the
operator’s EFVS authorization when flying into very low or below minimum
conditions;
- Flight considerations for continuing past the FAF when below minimum
conditions are reported.
5. Interpretation of approach and runway lighting systems and their display
characteristics when using an EFVS:
a. Approach lighting systems;
b. Runway lighting systems;
c. Taxiway lighting systems; and
41
07/26/13
AC 90-106A
d. LVO/SMGCS-specific lighting systems.
42
07/26/13
AC 90-106A
Initial Flight Training.
5.3.1. 14 CFR §§ 61.31(l)(3) and (4) contain the flight training requirements for EFVS I and
EFVS II operations. Under § 61.31(l)(3), any person manipulating the controls of an
aircraft or acting as PIC of an aircraft during an EFVS operation must receive flight
training from an authorized instructor under a training program approved by the
Administrator. In addition, the pilot must obtain a logbook or other endorsement from the
authorized instructor who certifies that he or she satisfactorily completed the flight
training and is proficient in the use of EFVS. To provide the endorsement, the authorized
instructor must also meet the requirements of § 61.31(l). These flight training
requirements apply to both EFVS I and EFVS II operations. Section 61.31(l)(7) contains
certain exceptions to the § 61.31(l)(3) flight training required to conduct EFVS
operations. Section 5.4 explains these exceptions. The definition of an “authorized
instructor” can be found in § 61.1(b)(2), and section 5.7 of this AC explains what a
“training program approved by the Administrator” means.
5.3.2. Under § 61.31(l), a person who serves as a required pilot flight crewmember during an
EFVS I or EFVS II operation, but who does not manipulate the controls or serve as PIC
of that aircraft, is not required to receive EFVS flight training. As discussed in Section
5.2.4, pilots should be aware that § 61.55 requires any person serving as second-incommand to be familiar with the operational procedures applicable to an aircraft’s
powerplant; equipment and systems; performance specifications and limitations; its
normal, abnormal, and emergency procedures; and flight manual, placards and markings.
Part 61 contains the minimum training requirements for EFVS operations. In addition to
the Part 61 requirements, pilots must also comply with the training provisions of the part
under which they conduct flight operations. Part 121, for example, requires ground and
flight training appropriate to the particular assignment of the pilot flight crewmember.
Error! Reference source not found.
5.3.3. Flight training must, at a minimum, consist of the following subjects in accordance with
§ 61.31(l)(4):
1. Preflight and inflight preparation of EFVS equipment for EFVS operations, including
EFVS setup and use of display, controls, modes, and associated systems, including
adjustments for brightness and contrast under day and night conditions;
2. Proper piloting techniques associated with using EFVS during taxi, takeoff, climb,
cruise, descent, landing, and rollout, to include missed approaches and balked
landings;
3. Proper piloting techniques for the use of EFVS during instrument approaches, to
include operations below DA/DH or MDA in accordance with § 91.176, as
applicable, under both day and night conditions;
4. Determining enhanced flight visibility;
5. Identifying required visual references appropriate to EFVS operations;
43
07/26/13
AC 90-106A
6. Transitioning from EFVS sensor imagery to natural vision acquisition of required
visual references and the runway environment;
7. Using EFVS sensor imagery to touchdown and rollout, if EFVS operations as
specified in § 91.176(a) are to be conducted; and
8. Normal, abnormal, emergency, and crew coordination procedures when using an
EFVS, including crew procedures for using the pilot monitoring (PM) display.
5.3.4. For certain flight training requirements listed in Section 5.3.3, the FAA recommends that
flight training address the following additional subject areas:
1. Preflight and inflight preparation of EFVS equipment for EFVS operations, including
EFVS setup and use of display, controls, modes, and associated systems, including
adjustments for brightness and contrast under day and night conditions:
a. Importance of the “design eye position” in acquiring the proper EFVS image;
b. Crew briefings, procedures, callouts, and coordination items for preflight and
inflight preparation of EFVS equipment.
2. Proper piloting techniques associated with using EFVS during taxi, takeoff, climb,
cruise, descent, landing, and rollout, to include missed approaches and balked
landings:
a. Crew briefings, procedures, callouts, and coordination items for EFVS operations,
including annunciation of published minima and operation below the DA/DH or
MDA;
b. Missed approach procedures – all engines and engine inoperative; and
c. Use of on/off switch “clear” mode.
3. Proper piloting techniques for the use of EFVS during instrument approaches, to
include operations below DA/DH or MDA in accordance with § 91.176, as
applicable, under both day and night conditions:
a. Training items should be consistent with the operator’s authorization to conduct
EFVS operations. For example, training to conduct EFVS operations on
nonprecision approaches is not required if the operator does not conduct them and
their authorization does not permit them. Other conditions and/or limitations may
affect an operator’s training curriculum content;
b. Straight-in precision approaches, approaches with approved vertical guidance, and
nonprecision instrument approaches:
- In day and night Visual Flight Rules (VFR) and IFR conditions;
- Under various ceiling and low-visibility conditions;
- Using the FPV cue and FPARC during IFR approaches;
- Using different approach lighting configurations;
- Under various crosswind conditions;
44
07/26/13
AC 90-106A
-
-
To the extent practicable, approach to airports where there is a lack of on/off
airport visual cues, no runway centerline lights, and no TDZ lights using the
FPV cue and FPARC to simulate a “black hole” approach;
IAPs flown to flare, touchdown, and rollout consistent with the operator’s
authorization to conduct EFVS I or EFVS II operations;
Maximum offset angles associated with the various types of straight-in
instrument approach procedures the FAA has authorized an operator to
conduct, consistent with the operator’s authorization or the equipment
limitations of the AFM(S);
Use of caged and uncaged modes in crosswind conditions; and
Use of the EFVS repeater display (if installed).
4. Determining enhanced flight visibility:
a. Determining enhanced flight visibility over a range of actual or simulated lowvisibility conditions.
45
07/26/13
AC 90-106A
5. In addition to normal, abnormal, emergency, and crew coordination procedures when
using an EFVS, fight training should include crew procedures for using the pilot
monitoring (PM) display if such a display is installed in the operator’s aircraft.
5.3.5. The FAA recognizes that an operator may choose to limit their EFVS operations in
specific ways. For example, an operator may choose to conduct EFVS I operations only
on precision approaches and approaches with published vertical guidance, but not on
nonprecision approaches. Another operator may choose to tailor its EFVS operation in
other specific ways. In the example given, training to conduct EFVS I operations on
nonprecision approaches would not be required. The FAA can tailor an operator’s
authorization and training to the type of EFVS operation to be conducted and any
applicable operating limitations would be specified in the operator’s OpSpec, MSpec, or
LOA. In the example given, the operator’s OpSpec, MSpec, or LOA would authorize
them to conduct EFVS I operations only on precision approaches and approaches with
published vertical guidance. The FAA would not authorize nonprecision approaches for
that operator’s EFVS I operations.
5.3.6. The FAA assumes that an operator who conducts EFVS II operations will also train their
pilots to conduct EFVS I operations; specifically, the operator must train on the transition
from enhanced vision to natural vision at 100 feet above the TDZE. Under certain
circumstances, an operator authorized to conduct EFVS II operations might find it
necessary to conduct an EFVS I operation. One example could be when equipment, such
as the PM display, is inoperative. A PM display is required for an EFVS II operation
when a minimum of more than one pilot flightcrew member is required. It is not required
for an EFVS I operation, however. In this example, the flightcrew cannot conduct an
EFVS II operation because the PM display is inoperative, but they can conduct an EFVS
I operation provided they meet all of the other regulatory requirements for EFVS
operations.
5.3.7. The FAA considers it essential that pilots be trained and checked on the various types of
IAPs the FAA authorizes them to conduct. If an operator conducts EFVS I operations on
straight-in nonprecision approaches, they should conduct EFVS training on a range of
offset angles over a range of standard and lower-than-standard visibilities. A non-RNAV
nonprecision approach, for example, can be offset by as much as 30 degrees and be
considered straight-in. If an operator conducts EFVS I or EFVS II operations on straightin precision approaches and approaches with approved vertical guidance (i.e., published
vertical guidance), they should conduct training on the range of offset angles associated
with those IAPs and at various standard and lower-than-standard visibilities. Section
3.3.3., Offset Approaches, addresses offset angles associated with specific IAPs.
Exceptions to the Initial Ground and Flight Training Requirements of 14 CFR
61.31(l)(1) and (l)(3).
5.4.1. The ground training requirements of § 61.31(l)(1) and the flight training requirements of
§ 61.31 (l)(3) do not apply if a person has satisfactorily completed the following:
46
07/26/13


AC 90-106A
A pilot proficiency check on EFVS I or EFVS II operations as specified in
§ 91.176(a) or (b); or
A training program, proficiency check, or other course of instruction applicable to
EFVS I operations conducted under § 91.176(b) that is found to be acceptable to the
Administrator and was completed before [INSERT DATE TWO YEARS AFTER
THE EFFECTIVE DATE OF THE FINAL RULE].
5.4.2. A pilot who is excepted from the initial ground and flight training requirements of
§§ 61.31(l)(1) and (l)(3), based on having satisfactorily completed a pilot proficiency
check on EFVS I or EFVS II operations as specified in § 91.176(a) or (b), must have a
logbook endorsement stating that the pilot has satisfactorily completed the check. In
addition, the proficiency check must be applicable to the specific type of EFVS operation
the pilot will conduct – EFVS I and/or EFVS II. For example, a proficiency check
conducted for EFVS I operations would not meet the requirement for a proficiency check
for EFVS II operations. An EFVS I operation requires a transition from sensor imagery to
natural vision at 100 feet above the touchdown zone elevation, whereas, an EFVS II
operation relies on the sensor image to touchdown. Additionally, a proficiency check for
EFVS II operations may not meet all of the requirements for a proficiency check for
EFVS I operations because it may not include nonprecision approaches. A proficiency
check for EFVS II operations could be combined with a proficiency check for EFVS I
operations that addresses the conduct of nonprecision approaches, however. The purpose
of this exception is to give credit for EFVS ground and flight training a pilot may have
received other than through a Part 141 pilot school or a Part 142 training center or to
provide a means of demonstrating EFVS proficiency that may have been obtained by
other means. Under this provision, the pilot proficiency check must be conducted by:




An FAA inspector or designated examiner;
A person authorized by the U.S. Armed Forces to administer EFVS proficiency
checks, provided the person receiving the check was a member of the U.S. Armed
Forces at the time the check was administered;
An authorized instructor employed by a Federal, State, county, or municipal agency
to administer an EFVS proficiency check, provided the person receiving the check
was employed by that agency at the time the check was administered; or
A check airman under Part 121, 125, or 135, or a program manager check pilot under
check pilot under Part 91, subpart K.
5.4.3. The ground and flight training requirements of §§ 61.31(l)(1) and (l)(3) also do not apply
if a person has satisfactorily completed a training program, proficiency check, or other
course of instruction applicable to EFVS I operations conducted under § 91.176(b) that is
acceptable to the Administrator before [INSERT DATE 24 MONTHS AFTER THE
EFFECTIVE DATE OF THE FINAL RULE]. The purpose of this exception is to provide
pilots who were conducting EFVS I operations prior to the establishment of EFVS
training requirements in § 61.31 a reasonable means of demonstrating compliance with
the additional ground and flight training requirements of §§ 61.31(l)(1) and (l)(3). The
training program, proficiency check, or other course of instruction could have been
completed prior to the establishment of EFVS training requirements in § 61.31, but not
47
07/26/13
AC 90-106A
later than [INSERT DATE 24 MONTHS AFTER THE EFFECTIVE DATE OF THE
FINAL RULE]. To qualify for this exception, a pilot must be able to show a logbook
endorsement or other training record that indicates he or she satisfactorily completed a
training program, proficiency check, or other course of instruction applicable to EFVS I
operations that the FAA finds acceptable. Training the FAA finds acceptable under this
provision could be training conducted under Part 61, Part 141, Part 142, training
conducted by an air carrier, the military, a Federal, State, county, or municipal agency, a
corporate flight department, or another course of instruction the FAA might find
acceptable. The training need not be a training program that is approved by the FAA, but
to be acceptable, the course of instruction should cover the subjects required by
§ 61.31(l). If a proficiency check is used to establish the basis for this exception, the
proficiency check must be performed by:





An FAA Inspector or designated examiner who is qualified to perform EFVS
operations in that same aircraft category;
A person who is authorized by the U.S. Armed Forces to perform EFVS proficiency
checks, provided the person being administered the check is also a member of the
U.S. Armed Forces;
A company check pilot who is authorized to perform EFVS proficiency checks under
part 121, 125, 135, or subpart K of part 91 of 14 CFR, provided that both the check
pilot and the pilot being tested are employees of that operator or fractional ownership
program manager, as applicable;
An authorized instructor who meets the additional training requirements for EFVS
operations specified in § 61.31(l); or
A person approved by the FAA to perform EFVS proficiency checks.
Recurrent or Differences Training.
5.5.1. Recurrent and differences training for EFVS I and EFVS II operations should consist of
the same subject areas covered by initial training. Differences training for a new EFVS
system should also include special conditions or considerations associated with
conducting EFVS operations using the new system.
5.5.2. An operator may conduct less than the full range of EFVS operations permitted by the
regulations as a result of equipment limitations, operator choice, or other operating
considerations and limitations. For example, an operator’s aircraft may currently be
certified to only conduct EFVS I operations, and its pilots are only trained to conduct
those operations. That operator may later decide to certify its aircraft for EFVS II
operations. Because the operator’s pilots would have already completed initial EFVS I
ground and flight training, the FAA would only require them to complete differences
training applicable to EFVS II operations. In this case, the operator would be required to
complete ground and flight training that addresses the differences between the two types
of EFVS operations and amend their OpSpec, MSpec, or LOA authorization, as
applicable. Another example of when differences training is appropriate would be when
an operator who is authorized to conduct EFVS I operations only on precision approaches
applies for approval to also conduct them on approaches with approved vertical guidance
and on nonprecision approaches. As discussed in Sections 5.3.5 through 5.3.7, ground
48
07/26/13
AC 90-106A
and flight training that addresses the additional considerations applicable to the additional
approach procedures is required. Yet another example is an operator who conducts
operations under Part 135 whose OpSpec to conduct EFVS operations does not currently
authorize them to take off under IFR or begin an IAP when the weather at the destination
airport is reported to be below the authorized landing minimums for that airport. To
takeoff under IFR or to begin the IAP, the operator in this example would have to amend
their OpSpec authorization and complete differences training applicable to the new
operations the operator will conduct.
5.5.3. Successful completion of recurrent and differences training must be documented by a
logbook or other endorsement from an authorized instructor. In lieu of completing
recurrent or differences training, a pilot could complete a proficiency check on the
additional EFVS operations administered by an FAA inspector, designated examiner, a
check airman under Part 121, 125, or 135, or a program manager check pilot under Part
91, subpart K.
Aircraft or Flight Simulator Training.
5.6.1. Flight training for EFVS must be accomplished in the actual aircraft or in a simulator that
meets the requirements of § 61.31(l)(5). A flight simulator used to meet the flight training
requirements specified in § 61.31(l)(3) must be equipped with an EFVS and must be a
level 'C' simulator with a daylight visual display, or a level 'D' simulator. The National
Simulator Program must qualify each simulator for EFVS. You can find additional
information about the FAA National Simulator Program (NSP) at
http://www.faa.gov/safety/programs_initiatives/aircraft_aviation/nsp/.
5.6.2. In FSB Reports, the FAA recommends that each pilot who manipulates the controls
during an EFVS operation should receive at least a minimum of 4 hours of initial ground
training followed by a minimum of 2 hours of flight training using an EFVS in an EFVSequipped aircraft or in an EFVS-equipped and qualified flight simulator. This assumes
the pilot is already trained and proficient in the use of the HUD installed on the aircraft. If
the pilot is not trained and proficient in the use of the HUD, the pilot may require more
training time. The pilot may accomplish HUD training concurrently with EFVS training.
Additional training time may also be required depending on the EFVS operations the
operator expects to conduct.
5.6.3. The simulator’s out-the-window visibility and EFVS enhanced flight visibility should be
adjustable and should be set to realistic values during training.
Approved EFVS Training Program.
5.7.1. The regulations require a pilot to receive training from an authorized instructor under a
training program approved by the Administrator. A training program approved by the
Administrator could include EFVS training received through a training program approved
under Part 121, 125 or 135, a Part 141 pilot school, a Part 142 training center, or FAAapproved training given under Part 61. The FAA approves EFVS training conducted
under Part 121, 125, 135, 141, or 142 using existing processes. An operator or training
49
07/26/13
AC 90-106A
provider who wishes to obtain approval to provide EFVS training under Part 61 should
submit the ground and/or flight training curriculum for EFVS to the Flight Standards
District Office with geographic responsibility for the operator or for the training provider,
as appropriate. At a minimum, the training program must contain the subject areas
specified in § 61.31(l).
50
07/26/13
6.
AC 90-106A
Recent Flight Experience and Proficiency Requirements for EFVS Operations
Recent Flight Experience Requirements for EFVS Operations.
6.1.1. EFVS operations are complex operations involving the use of a HUD with a sensor image
that a pilot typically conducts in low-visibility conditions. Because the occurrence of
low-visibility conditions is infrequent, and because the skills necessary to operate EFVS
equipment under these conditions are perishable, recent EFVS flight experience is
necessary to prevent the loss of skill. The purpose of requiring recent EFVS flight
experience is to ensure that a pilot remains proficient in the use of all EFVS components
and operating procedures and to ensure that the pilot conducts EFVS operations safely.
As EFVS equipment evolves to permit operations in lower visibility environments than
are currently permitted, and as the scope and number of EFVS operations increases over
time, the need for pilots to maintain recent flight experience becomes even more critical.
6.1.2. 14 CFR § 61.57(h) specifies that a person who manipulates the controls of an aircraft
during an EFVS operation or who acts as PIC of an aircraft during an EFVS operation,
can do so only if, within 6 calendar months preceding the month of the flight, that person
performs and logs six instrument approaches as the sole manipulator of the controls using
an EFVS. The recent flight experience requirements specified in § 61.57(h) apply to both
EFVS I and EFVS II operations. Unlike the instrument experience requirements specified
in § 61.57(c), these approaches need not be conducted in actual weather conditions or
under simulated conditions using a view-limiting device. Since the EFVS can present a
sensor image to the pilot in both IFR and VFR weather conditions, the pilot may conduct
these approaches under any weather conditions. One approach must terminate in a full
stop landing. Pilots who conduct EFVS II operations must conduct the full stop landing
using the EFVS.
6.1.3. In accordance with the provisions of § 61.57(e)(2), the recent flight experience
requirements specified in § 61.57(h) do not apply to a PIC who is employed by an air
carrier certificated to conduct operations under Part 121 or 135. The pilot, however, must
be engaged in a flight operation under Part 91, 121, or 135 for that air carrier and in
compliance with §§121.437 and 121.439, or §§135.243 and 135.247, as appropriate.
Additionally, § 91.176 requires each pilot flight crewmember to meet the applicable
training, testing, and qualification provisions of Part 121 or 135, as appropriate.
6.1.4. The recent flight experience requirements of § 61.57(h) can be met in an aircraft or in a
simulator equipped with an EFVS. If an EFVS-equipped simulator is used, it must be a
level “C” simulator, with a daylight visual display, or a level “D” simulator that the FAA
National Simulator Program (NSP) has qualified for EFVS.
Proficiency Check Requirements for EFVS Operations.
6.2.1. Under § 61.57(i), a person acting as PIC or a person who is manipulating the controls of
an aircraft in an EFVS operation must either meet the recent flight experience
requirements of § 61.57(h) or pass an EFVS proficiency check. The proficiency check
must consist of the training tasks specified in § 61.31(l) and must be performed in the
51
07/26/13
AC 90-106A
category of aircraft for which the person is seeking the EFVS privilege or in a flight
simulator that is representative of that category of aircraft. If the pilot uses a flight
simulator to accomplish the proficiency check, it must be equipped with an EFVS and
must be a level “C” simulator, with a daylight visual display, or a level “D” simulator that
the FAA NSP has qualified for EFVS.
6.2.2. An EFVS proficiency check must be performed by:





An FAA Inspector or designated examiner who is qualified to perform EFVS
operations in that same aircraft category;
A person who is authorized by the U.S. Armed Forces to perform EFVS proficiency
checks, provided the person being administered the check is also a member of the
U.S. Armed Forces;
A company check pilot who is authorized to perform EFVS proficiency checks under
Part 121, 125, or 135 or subpart K of Part 91 of 14 CFR, and provided that both the
check pilot and the pilot being tested are employees of that operator or fractional
ownership program manager, as applicable;
An authorized instructor who meets the additional training requirements for EFVS
operations specified in § 61.31(l) and when conducting a proficiency check in an
aircraft the recent flight experience specified in § 61.57(h) or (i); or
A person the FAA has approved to perform EFVS proficiency checks.
52
07/26/13
7.
AC 90-106A
Training for Dispatchers and Other Persons Authorized to Exercise Operational
Control for EFVS Operations
Dispatch, Flight Release and Flight Following Considerations.
7.1.1. The regulatory requirements pertaining to dispatch, flight release, and takeoff under IFR
for operators conducting EFVS operations under Part 121, 125, or 135 when the
destination airport visibility is below authorized minimums are discussed in detail in
Section 4.1. Section 4.2 addresses the regulatory requirements pertaining to initiating or
continuing an approach using EFVS when the reported visibility is below the minimum
authorized visibility for the approach to be flown for operations conducted under Part
121, 125, or 135. This section addresses training for dispatchers and other persons
authorized to exercise operational control for EFVS operations.
7.1.2. With careful flight planning, detailed weather analysis, and proper training, EFVS
equipment can greatly enhance operational safety and access to airports. To ensure that
an approach and landing can be successfully completed using EFVS, it is essential that
dispatchers and other persons authorized to exercise operational control fully understand
the capabilities and limitations of the specific EFVS equipment installed in the operator’s
aircraft. Unique weather conditions that cause variability in how an EFVS sensor
performs, or weather conditions that exceed the sensor’s ability to provide the enhanced
flight visibility required to complete the approach and landing, should be understood and
accounted for when dispatching an aircraft, releasing an aircraft, or taking off under IFR
for the purpose of conducting EFVS operations. Operators who do not have dispatch or
flight release personnel, such as an operation conducted under Part 135, should be
especially aware of weather and operational factors that could affect EFVS performance
when they are considering takeoff under IFR, or when conditions at their destination
airport are forecasted or reported to be below visibility minimums for the approach to be
flown. Operational planning and continuous monitoring of weather conditions at the
destination airport are especially important under these circumstances.
7.1.3. It is also important to understand that air traffic flow at many airports is constrained by
weather conditions other than wind. Dispatching or releasing an aircraft to an airport
where the pilot must conduct an EFVS operation due to low visibility should consider air
traffic flow to that airport. During some CAT II or III approach conditions, a pilot who
wishes to conduct an approach using EFVS to a different runway than is being used for
CAT II or III operations may not be cleared by air traffic control to conduct an approach
to that runway due to traffic flow or other conditions, irrespective of the provisions of the
EFVS regulations or the aircraft’s capability to conduct EFVS operations. As a result,
increased fuel for holding could be required due to limited runway capacity.
7.1.4. Airports certificated under Part 139 will have restrictions affecting surface movement
operations when RVR values are reported to be approaching or are less than RVR 1200
feet. Each airport approved for operations below RVR 1200 feet develops LVO/SMGCS
taxi routes, surface movement restrictions, and air traffic coordination procedures. The
FAA-approved LVO/SMGCS plan can limit availability of runways for takeoff and
landing. Taxiways not included in the LVO/SMGCS plan may not be available to an
53
07/26/13
AC 90-106A
operator, even though EFVS may provide significant visual benefits during ground
movement. Operators, dispatchers, and other persons authorized to exercise operational
control should check with the airport operator for specific airport procedures. FAA Order
8000.94, Procedures for Establishing Airport Low-Visibility Operations and Approval of
Low-Visibility Operations/Surface Movement Guidance and Control System Operations,
and AC 120-57, Surface Movement Guidance and Control System, provides standards
and guidance for LVO/SMGCS operations.
Initial Training for Dispatchers and Other Persons Authorized to Exercise
Operational Control.
7.2.1. Initial training for dispatchers and other persons authorized to exercise operational
control should consist of the following:
1. Regulatory requirements applicable to the EFVS operation(s) the operator will
conduct (e.g., EFVS I or EFVS II):
a. Operational concept for EFVS I and EFVS II operations;
b. Regulatory requirements for EFVS operations contained in §§ 91.175(d)(1),
91.175(e)(1), 91.176, and 91.189(d) and (e);
c. Regulatory requirements for pilot training, recent flight experience, and
proficiency contained in §§ 61.31(l) and 61.57(h) and (i);
d. Regulatory requirements contained in §§ 121.613, 121.615(a), 125.361,
125.363(a), and 135.219, as applicable, for dispatch, flight release, or takeoff
under IFR using an EFVS-equipped aircraft when the reported or forecast
visibility at the destination airport is below authorized minimums ;
e. Regulatory requirements contained in §§ 121.651, 125.325, 125.381, and
135.225, as applicable, for initiating or continuing an approach when the
destination airport visibility is below authorized minimums;
f. IAPs approved and not approved for EFVS I and EFVS II operations;
g. Enhanced flight visibility requirements contained in §§ 91.176(a) and (b);
h. Visual reference requirements contained in §§ 91.176(a) and (b), including a
comparison of visual references required by § 91.175(c) using natural vision and
§§ 91.176(a) and (b) using EFVS;
i. OpSpec or LOA requirements pertinent to the EFVS operation the pilot will
conduct; and
j. Exemptions or deviations from the regulations that pertain to the use of EFVS, if
any.
2. AFM/AFMS material pertinent to EFVS operations:
a. Type of EFVS operation the FAA has certified the operator’s aircraft to conduct;
b. EFVS system description and operating limitations; and
c. Normal, abnormal, and emergency procedures pertaining to the operator’s EFVS,
including an understanding of pilot flying and pilot monitoring duties, and
decision points throughout the EFVS operation.
54
07/26/13
AC 90-106A
3. Sensor technology, performance, and limitations:
a. Understanding the specific EFVS sensor technology or technologies installed on
the operator’s aircraft;
b. EFVS sensor performance in varying weather conditions;
c. EFVS sensor limitations, including variable, unpredictable, or unusual
performance characteristics;
d. Weather conditions that exceed the EFVS sensor’s ability to provide the enhanced
flight visibility required to complete the approach and landing;
e. The EFVS sensor’s ability to detect or not detect obstacles in the environment;
and
f. EFVS sensor performance and limitations associated with specific types of
lighting such as incandescent lamps and LEDs.
4. EFVS dispatch or flight release requirements for destination airports and for initiating
and continuing an approach using EFVS when the destination airport visibility is
below authorized minimums;
5. Considerations for diverting to alternate airports;
6. Procedures for redispatch en route with respect to EFVS operations;
7. MEL/CDL dispatch/flight release requirements and considerations;
8. Use of barometric and/or radio altitude at low heights, including temperature
correction if applicable;
9. Use and limitations of supplementary or advisory vertical information for situation
awareness below DA/DH or MDA;
10. Effect of crosswinds on EFVS field of view for approaches aligned with the runway
centerline and for straight-in approaches that are offset from the runway centerline;
11. Runway, taxiway, and approach lighting system configurations; and
12. Capabilities and limitations of EFVS for low-visibility taxi, including operating
considerations when LVO/SMGCS plans are in effect.
7.2.2. During initial training, the FAA encourages dispatchers or other persons authorized to
exercise operational control to experience a training event in a flight simulator or an
actual airplane that allows them to observe a flight crew conducting an EFVS I or EFVS
II operation. If a flight simulator is used, it should be equipped with an EFVS, and should
be a level 'C' simulator with a daylight visual display, or a level 'D' simulator that has
been qualified by the NSP for EFVS. The purpose of this training event is to provide an
opportunity for dispatchers and other persons authorized to exercise operational control
to understand what an EFVS operation is, what the enhanced flight visibility and visual
reference requirements for the operation are, the challenges that variable sensor
performance present to the flight crew, and how critical the dispatch, flight release, or
55
07/26/13
AC 90-106A
flight following functions are. If a training event in a flight simulator or airplane is not
possible, training material that addresses these elements during the conduct of an EFVS I
or EFVS II operation may be developed and shown to the person being trained. For
persons conducting operations under Part 121, the simulator training event could fulfill
the annual operating familiarization required by § 121.463.
Recurrent and Differences Training for Dispatch and Flight Release Personnel.
7.3.1. Recurrent and differences training for dispatchers and other persons authorized to
exercise operational control should consist of the same subject areas covered by initial
training. Differences training for a new EFVS system should also include special
conditions or considerations associated with conducting EFVS operations using the new
system.
56
07/26/13
8.
AC 90-106A
Aircraft Qualification and Maintenance Program Requirements
General.
8.1.1. This section contains guidance on aircraft qualification and maintenance program
requirements associated with EFVS I and EFVS II operations. Operators should address
these requirements in applications submitted to the FAA for authorization to conduct
EFVS operations. Section 10 contains additional information about the application
process.
Applicability.
8.2.1. Aircraft qualification and maintenance requirements apply to EFVS I and EFVS II
operations that are conducted under Parts 91, 91 subpart K, 121, 125, 129, and 135. All
operators must submit an application for approval to conduct EFVS I operations, except
for Part 91 operators (other than Part 91, subpart K operators) who wish to conduct only
EFVS I operations. Operators other than a Part 91 operator who wish to conduct only
EFVS I operations must submit an application that addresses the qualification and
maintenance requirements, as applicable, that are specified in this section. All operators,
including Part 91 operators, who wish to conduct EFVS II operations must submit an
application that addresses the qualification and maintenance requirements as applicable,
that are specified in this section.
8.2.2. Part 91 operators who wish to conduct only EFVS I operations should be aware that their
aircraft must still be qualified to conduct EFVS I operations. That is, their U.S.-registered
aircraft must comply with the equipment requirements of 91.176(b)(1) and must have a
TC, STC, or ATC to conduct EFVS I operations. Accordingly, a Part 91 operator of a
U.S.-registered aircraft must maintain the aircraft in accordance with the maintenance,
preventive maintenance, and alterations requirements specified in Parts 91 and 43.
Aircraft Qualification Requirements.
8.3.1. An EFVS installed on a U.S.-registered aircraft that is used to conduct EFVS I and EFVS
II operations must be operable and must be installed in accordance with an FAA type
design approval (a TC, ATC, or STC). A field approval is not an acceptable means of
EFVS installation for operations conducted under § 91.176(a) or (b). A foreign-registered
aircraft used to conduct EFVS operations that does not have an FAA type design
approval must be equipped with an operable EFVS that otherwise meets the requirements
of the U.S. regulations.
8.3.2. Applications for authorization to conduct EFVS I or EFVS II operations should contain
the following documentation and information to establish that the aircraft qualifies for
EFVS operations:
1. Applicable EFVS airworthiness documentation that indicates the EFVS was installed
pursuant to an FAA type design approval or for foreign-registered aircraft, that the
EFVS otherwise meets the requirements of the U.S. regulations
57
07/26/13
AC 90-106A
2. EFVS manufacturer’s Instructions for Continued Airworthiness (ICA) as accepted by
the FAA, and
3. Proposed Minimum Equipment List (MEL) revisions, if applicable, listing any
limitations associated with EFVS I or EFVS II operations.
Maintenance Program.
8.4.1. Applications for authorization to conduct EFVS I or EFVS II operations should include
the operator’s maintenance program and should address specific policy and procedures
that apply to continuing airworthiness of the EFVS.
8.4.2. Except for operators conducting EFVS I operations under Part 91, applications for
authorization to conduct EFVS operations under Parts 91 subpart K, 121, 125, 129, and
135 should include the following:
1. The General Maintenance Manual (GMM) must incorporate the EFVS
manufacturer’s ICA, as accepted by the FAA, and identify any special techniques,
maintenance/inspection frequencies, and test equipment required to support the
continued airworthiness of the system;
2. Indicate whether the EFVS maintenance program is integrated into an existing
approved maintenance program (e.g., lower landing minima program) or a separate
program;
3. Identify the GMM revision and update procedures, if not previously approved by the
FAA;
4. Identify how maintenance personnel will be trained and qualified on the EFVS and
the method to record and maintain their qualifications;
5. Procedures for EFVS software installation, updating, evaluation, testing and control;
6. Procedures used to make modifications, additions, and changes to the EFVS;
7. Procedures for EFVS discrepancy reporting and recording;
8. Procedures for MEL and logbook pertaining to upgrade/downgrade/deferral of the
EFVS;
9. Procedures for MEL (remarks section, limitations, upgrade/downgrade) that ensure
the EFVS status is placarded properly and clearly documented in the aircraft log
book;
10. Procedures for notification between maintenance control, engineering, flight
operations, and dispatch, or equivalent, when an aircraft’s EFVS status changes;
58
07/26/13
AC 90-106A
11. Procedures to ensure the downgrade of an aircraft’s EFVS status, if applicable, when
maintenance was performed on the EFVS by nonqualified persons;
12. Procedures to monitor and identify aircraft with chronic EFVS discrepancies and
restrict the aircraft from EFVS operations until appropriate corrective action and tests
have been performed;
13. Procedures for return to service (RTS) of an EFVS following routine/nonroutine
maintenance or completion of corrective action on an aircraft flagged for chronic
discrepancies, including:
a.
b.
c.
d.
Required tests for RTS
Functional flight test requirements
Component mount or rack removal/installation
Structural damage or modification affecting EFVS optical alignment or system
performance, and
e. Interchange of EFVS I or EFVS II component allowances/restrictions.
14. Integration of EFVS program into Quality Control and Analysis (QA) Program;
15. Procedures for periodic performance sampling;
16. Procedures to ensure appropriate EFVS I and EFVS II parts handling, if applicable:
a. Identification/segregation
b. Component tracking and control procedures, and
c. Component modification tracking procedures resulting from Airworthiness
Directives, engineering orders, etc.).
17. Required Inspection Item (RII) components, systems, and software (if applicable).
8.4.3. Maintenance personnel should be familiar with the operator’s approved program, their
individual responsibilities with respect to that program, and the availability of any
resources within or outside of the maintenance organization necessary to ensure program
effectiveness.
59
07/26/13
9.
AC 90-106A
Maintenance Training for EFVS Operations
General.
9.1.1. This section contains guidance on maintenance personnel training requirements
associated with EFVS I and EFVS II operations. Operators should address these
requirements in proposals submitted to the FAA for authorization to conduct EFVS
operations. Section 10 contains additional information about the application process.
Maintenance Training
9.2.1. Maintenance personnel should be knowledgeable of the guidance contained in this AC
and applicable regulations. Operator and contract maintenance personnel, including
mechanics, maintenance controllers, avionics technicians, and inspection/quality
assurance personnel should receive initial and recurrent training to establish and maintain
an effective EFVS maintenance program.
9.2.1.1. Applications submitted for authorization to conduct EFVS I or EFVS II operations
should address the following maintenance training items:
1. Identify the person(s) responsible for ensuring EFVS maintenance and inspection
personnel are properly trained, knowledgeable, and current in accordance with the
GMM
2. Identify how the EFVS training will be conducted (i.e., in-house or outside training
provider)
3. Include policy and procedures that address the qualification requirements of EFVS
maintenance and inspection personnel
4. Identify the methods and techniques used to conduct initial and recurrent training
(e.g., instructor led, computer-based, OJT, etc)
5. Identify the procedures used to record and maintain the training required for initial
and recurrent EFVS qualifications
6. Include the EFVS maintenance and inspection training curriculum that addresses the
following topics:
a.
b.
c.
d.
e.
Operational overview
EFVS system overview
EFVS maintenance and inspection procedures
EFVS personnel training qualification requirements for EFVS I and EFVS II
EFVS I and EFVS II upgrade/downgrade procedures, including applicable
status change notifications
f. MEL procedures
g. Test equipment and use
h. Return to service tests and procedures, and
60
07/26/13
AC 90-106A
i. EFVS parts handling procedures, including handling of outside vendor parts.
61
07/26/13
10.
AC 90-106A
Operational Approval Process for EFVS Operations
Approval Process Overview.
10.1.1. The approval process is an orderly method used by FAA Flight Standards inspectors to
ensure operators meet regulatory standards and provide for safe operating practices. The
process consists of five distinct, yet related, phases and can result in approving or not
approving an operator’s proposal. The process consists of the following five phases:
10.1.1.1. Phase One – Pre-Application. Phase One of the approval process begins when an
operator requests authorization from the FAA to conduct EFVS operations. The FAA
Certificate-Holding District Office (CHDO) or Flight Standards District Office
(FSDO) responsible for that operator and the operator must reach a common
understanding of what the operator must do, what role the FAA will have, and what
form, content, and documents are required for submission.
10.1.1.2. Phase Two – Formal Application. Phase Two begins when the operator submits a
proposal to the FAA for formal evaluation. During this phase, the FAA reviews the
operator’s submission to ensure that the operator has clearly defined the proposal and
provides the documentation specified in Phase One. The required information must be
complete and detailed enough to permit a thorough evaluation of the operator’s
capability and competence to satisfy fully the applicable regulations, national policy,
and safe operating practices. The POI facilitates coordination with the appropriate
Aircraft Evaluation Group (AEG) and Aircraft Certification Office (ACO), and the
Regional Flight Standards Division (RFSD), as necessary.
10.1.1.3. Phase Three – Document Compliance. Phase Three begins when the FAA starts its
indepth review and analysis of the operator’s proposal. In this phase, the FAA
evaluates the proposal to determine that it is not contrary to applicable FAA
regulations, FAA guidance, or other safety-related documents, and provides for safe
operating practices. Planning for Phase Four also begins as the FAA starts to
formulate plans to observe and evaluate the operator’s ability to perform.
10.1.1.4. Phase Four – Demonstration and Inspection. Phase Four is the major validation
phase of the process referred to as the Operational Use Suitability Demonstration
(OUSD). It is an operational evaluation of the operator’s ability to function in
accordance with the proposal evaluated in Phase Three. The purpose of an OUSD is to
demonstrate and validate the ability of the operator to:



Maintain and operate its EFVS equipment;
Achieve an acceptable level of EFVS equipment reliability; and
Perform EFVS operations during line operations in a manner consistent with the
concepts specified in this AC.
OUSD requirements may include criteria and special emphasis items from FSB reports
applicable to the EFVS/aircraft installation, previous operator service experience,
experience other operators may have with a specific EFVS/aircraft installation,
62
07/26/13
AC 90-106A
experience the operator’s crews have with EFVS, and other factors the FAA deems
appropriate. In this phase, the FAA finalizes plans to observe and evaluate the
operator’s demonstration of its ability to perform in accordance with the procedures,
guidelines, and parameters described in the formal proposal. Phase Four concludes
when the operator provides sufficient proof to satisfy the FAA’s requirements for
meeting all the plan objectives or when the operator is unable to complete them
satisfactorily.
10.1.1.5. Phase Five – Approval. In Phase Five, the FAA approves the operator’s proposal. If
the FAA does not approve the proposal, they notify the operator in Phase Three or
Four. The operations inspector with oversight responsibility for the operator grants
approval for the operational use of the EFVS through the issuance of OpSpecs,
MSpecs, or an LOA.
Authorizations to Conduct EFVS Operations.
10.2.1. The FAA requires an authorization for persons conducting EFVS I operations under Parts
91, subpart K, 121, 125, 129, and 135 as follows:




A person who conducts EFVS I operations under Part 91, subpart K must do so in
accordance with MSpecs authorizing the use of EFVS;
Persons who conduct EFVS I operations under Part 121, 129, or 135 must do so in
accordance with OpSpecs authorizing the use of EFVS;
A person who conducts EFVS I operations under Part 125 must do so in accordance
with OpSpecs authorizing the use of EFVS, or in the case of a Part 125 LODA holder,
an LOA for the use of EFVS; and
Part 91 operators (other than Part 91, subpart K operators) are not required to obtain
an LOA to conduct EFVS I operations.
10.2.2. The FAA requires an authorization for all persons conducting EFVS II operations under
Parts 91, 121, 125, 129, and 135 as follows:




A person who conducts EFVS II operations under Part 91 (other than Part 91, subpart
K) must do so in accordance with an LOA for EFVS II operations;
A person conducting EFVS II operations under Part 91, subpart K must conduct them
in accordance with MSpecs authorizing the use of EFVS;
Persons who conduct EFVS II operations under Part 121, 129, or 135 must do so in
accordance with OpSpecs authorizing the use of EFVS; and
A person who conducts EFVS II operations under Part 125 must do so in accordance
with OpSpecs authorizing the use of EFVS, or in the case of a Part 125 LODA holder,
an LOA for the use of EFVS.
10.2.3. The FAA authorizes EFVS operations through a specific OpSpec, MSpec, or LOA,
depending on the level of EFVS operation the operator will conduct and whether the
operator plans to dispatch, release a flight, or takeoff under IFR or to initiate and continue
an approach when the destination airport weather is below authorized visibility
63
07/26/13
AC 90-106A
minimums for the runway of intended landing. Following are the specific OpSpec,
MSpec, or LOA designations and authorizations:



The FAA issues OpSpec C048, MSpec MC048, or LOA C048 to an operator who is
conducting an EFVS I operation, but who is not requesting authorization to dispatch,
release a flight, or takeoff under IFR or to initiate and continue an approach when the
destination airport weather is below authorized visibility minimums for the runway of
intended landing;
The FAA issues OpSpec C348, MSpec MC348, or LOA C348 to an operator who is
conducting an EFVS I operation and who is also requesting authorization to dispatch,
release a flight, or takeoff under IFR or to initiate and continue an approach when the
destination airport weather is below authorized visibility minimums for the runway of
intended landing; and
The FAA also issues OpSpec C348, MSpec MC348, or LOA C348 to an operator
who is conducting EFVS II operations whether or not they are also requesting
authorization to dispatch, release a flight, or takeoff under IFR or to initiate and
continue an approach when the destination airport weather is below authorized
visibility minimums for the runway of intended landing.
64
07/26/13
AC 90-106A
Approval Process for EFVS I Operations Conducted Under Part 91 subpart K, 121,
125, or 135 and EFVS II Operations Conducted Under Part 91, 121, 125, or 135.
10.3.1. Application Process. After meeting with the CHDO or FSDO, as applicable, operators
should submit a request for authorization to use an EFVS, along with supporting
information and documentation, to the FAA POI identified during the initial Phase One
meeting. The major components of an EFVS application should include the following
required documents:
1. Application letter describing the level of EFVS operation to be conducted (i.e., EFVS
I, EFVS II, or both), including whether the operator is requesting authorization to
dispatch, release a flight, or takeoff under IFR or to initiate and continue an approach
when the destination airport weather is below authorized visibility minimums for the
runway of intended landing;
2. Description of aircraft and equipment the operator proposes to use for EFVS
operations;
3. Applicable EFVS airworthiness documentation that indicates the EFVS was installed
pursuant to an FAA type design approval or for foreign-registered aircraft, that the
EFVS otherwise meets the requirements of the U.S. regulations;
4. Evidence that the applicant has reviewed and addressed the recommendations
specified in the applicable FSB report;
5. EFVS provisions contained in the AFM/AFMS, Airplane Operations Manual (AOM),
Flight Operations Manual (FOM), Pilot’s Operating Handbook (POH),
QuickReference Handbook (QRH), as applicable;
6. MEL for EFVS operations and any proposed changes, if the operator seeks MEL
relief for EFVS;
7. EFVS operating procedures -- checklists, crew coordination and monitoring
procedures, callouts, crew briefings, nonnormal operations and procedures related to
EFVS, and special environmental considerations for EFVS, if any;
8. Proposed flightcrew training program -- PIC, Second in Command, ground,
simulator, actual aircraft, initial, recurrent, upgrade, differences, and any other type of
training the flightcrew will conduct;
9. Procedures and training program, as applicable, for dispatchers and other persons
authorized to exercise operational control for EFVS operations;
10. Maintenance program, policies, procedures, and training, as applicable, for EFVS
operations; and
11. OpSpec/MSpec/LOA sought by the operator and any proposed amendments.
65
07/26/13
AC 90-106A
Approval Process for EFVS Operations Conducted Under Part 129.
10.4.1. Foreign Air Carrier Operations in the United States.
10.4.1.1. A foreign-registered aircraft used to conduct EFVS operations that does not have an
FAA-type design approval must be equipped with an operable EFVS that otherwise
meets the requirements of the U.S. regulations. That is, it must comply with all of the
EFVS equipment requirements of the U.S. regulations, be equipped with an EFVS that
meets § 1.1, and have the characteristics set forth in § 91.176 for the level of EFVS
operation to be conducted (i.e., EFVS I or EFVS II).
10.4.1.2. The appropriate International Field Office (IFO) or International Field Unit (IFU) is
responsible for authorizing Part 129 foreign air carriers for EFVS operations. This
authorization is based primarily on an EFVS authorization from the State of the
Operator. The major components of a foreign air carrier’s application to conduct
EFVS operations in the United States should include:
1. Application letter;
2. Description of aircraft and equipment proposed to be used for EFVS operations;
3. Airworthiness documentation;
4. AFM provisions for EFVS. Foreign-registered aircraft used by a foreign air
carrier for EFVS operations within the United States must have AFM provisions
reflecting an appropriate level of EFVS capability that meets the display, features,
and characteristics of § 91.176;
5. MEL approval, including any EFVS provisions. (FAA-approved MEL required
for U.S.-registered aircraft.) In accordance with § 129.14(b), no foreign air carrier
or foreign person may operate a U.S.-registered aircraft with inoperable
instruments or equipment unless a Master Minimum Equipment List (MMEL)
exists for the aircraft type, and the foreign operator submits for review and
approval its aircraft MEL, based on the MMEL, to the FAA. For EFVS
operations, the foreign operator should take the EFVS system and components
into consideration during MEL submission, review, and approval, if the foreign
operator is seeking MEL relief for EFVS;
6. EFVS operational approval issued by the CAA of the State of the operator;
7. EFVS training program approval issued by the CAA of the State of the operator;
8. Maintenance program approval, including EFVS provisions. (FAA-approved
maintenance program required for U.S.-registered aircraft.) In accordance with
§ 129.14, “each foreign air carrier and each foreign person operating a U.S.registered aircraft within or outside the United States in common carriage, will
ensure that each aircraft is maintained in accordance with a program approved by
the Administrator.” This maintenance program must contain maintenance
66
07/26/13
AC 90-106A
provisions for EFVS equipment; and
9. OpSpecs and any proposed amendments the operator is seeking.
10.4.1.3. U.S. and foreign regulations with respect to EFVS operations may differ. Foreign air
carriers operating aircraft under Part 129 in the United States should be familiar with
the equipment and operating requirements of the U.S. regulations. Additionally,
foreign operators that expect to conduct all of the approach operations authorized by
§ 91.176 must provide training appropriate to the approach operations to be conducted
and must be authorized by their CAA to conduct those operations.
10.4.2. Operations of U.S.-Registered Aircraft Solely Outside the United States. EFVS
operations conducted under Part 129 in U.S.-registered aircraft solely outside the United
States in common carriage by a foreign person or a foreign air carrier do not require
operational approval; however, those operations must comply with those sections of Part
129 specified in § 129.1(b).
Waivers to Conduct EFVS Operations
10.5.1. 14 CFR §§ 91.176(a)(1)(i), 91.176(a)(2)(ii), 91.176(b)(1)(i) and (ii), and 91.176(b)(2)(ii)
specify that no person may conduct an EFVS operation in an aircraft, except a military
aircraft of the United States, at any airport below the authorized DA/DH or MDA under
IFR unless the aircraft is equipped with an operable EFVS that has either an FAA type
design approval certified for EFVS operations to touchdown and rollout or an FAA type
design approval certified for EFVS operations down to 100 feet above the TDZE. An
operator who is conducting EFVS operations for research, development, or certification
purposes whose EFVS does not have an FAA type design approval may not descend
below DA/DH or MDA under IFR while relying on the EFVS unless they obtain a
certificate of waiver from the FAA to do so.
10.5.2. 14 CFR Section § 91.903 specifies that the Administrator may issue a certificate of
waiver authorizing the operation of aircraft in deviation from any rule listed in that
subpart if the Administrator finds that the proposed operation can be safely conducted
under the terms of the certificate of waiver. Section 91.905 contains a list of rules subject
to waiver, and § 91.176, Operation below DA/DH or MDA using an enhanced flight
vision system (EFVS) under IFR, is one of many rules listed. Operators should note that a
certificate of waiver may not be issued for any operation conducted under 121, 125, 129,
or 135.
10.5.3. Operators who seek a certificate of waiver must complete FAA Form 7711-2, Application
for a Certificate of Waiver or Authorization, and submit it to the FSDO having
jurisdiction over the area where the operator’s principal business office is located. The
application should be submitted a minimum of 30 days before the EFVS research,
development, or certification activity is scheduled to occur. In addition to Form 7711-2,
the FSDO may request supporting documentation consisting of the flight test plan, test
cards, hazard analysis and proposed mitigations, safety review board documents,
67
07/26/13
AC 90-106A
experimental operating limitations, or other documentation necessary to process the
application.
68
07/26/13
AC 90-106A
Appendix A
Appendix A. Acronyms and Abbreviations
Acronym
Definition
14 CFR
AC
ACO
AEG
AFM
AFMS
AFS
AIM
ALS
AOM
ATC
CAA
CAT I
CAT II
CAT III
CFIT
CFR
CHDO
CMU
DA
DH
EASA
EFVS
EVS
FAA
FAF
FLIR
FPARC
FPV
FOM
FPARC
FPV
FSB
FSDO
GLS
GMM
GPS
Title 14 of the Code of Federal Regulations
Advisory Circular
Aircraft Certification Office
Aircraft Evaluation Group
Aircraft Flight Manual
Airplane Flight Manual Supplement
Flight Standards Service
Aeronautical Information Manual
Approach Lighting System
Airplane Operations Manual
Amended Type Certificate
Civil Aviation Authority
Category I
Category II
Category III
Controlled Flight into Terrain
Code of Federal Regulations
Certificate-Holding District Office
Certificate Management Unit
Decision Altitude
Decision Height
European Aviation Safety Agency
Enhanced Flight Vision System
Enhanced Vision System
Federal Aviation Administration
Final Approach Fix
Forward-Looking Infrared
Flight Path Angle Reference Cue
Flight Path Vector
Flight Operations Manual
Flight Path Angle Reference Cue
Flight Path Vector
Flight Standardization Board
Flight Standards District Office
Ground Based Augmentation System [GBAS] Landing System
General Maintenance Manual
Global Positioning System
A-I
07/26/13
AC 90-106A
Appendix A
Acronym
Definition
GS
HAT
HDD
HUD
IAP
IFO
IFR
IFU
ILS
IMC
LDA
LED
LNAV
LOA
LODA
LP
LPV
LVO
MALSR
Glideslope
Height Above Touchdown
Head-Down Display
Head-Up Display
Instrument Approach Procedure
International Field Office
Instrument Flight Rules
International Field Unit
Instrument Landing System
Instrument Meteorological Conditions
Localizer-Type Directional Aid
Light-Emitting Diode
Lateral Navigation
Letter of Authorization
Letter of Deviation Authority
Localizer Performance
Localizer Performance with Vertical Guidance
Low Visibility Operations
Medium Intensity Approach Lighting System With Runway Alignment
Indicator Lights
Missed Approach Point
Minimum Aviation System Performance Standards
Minimum Descent Altitude
Minimum Equipment List
Microwave Landing System
Master Minimum Equipment List
Management Specification
National Airspace System
Non-Directional Radio Beacon
National Simulator Program
Operations Specification
Operational Use Suitability Demonstration
Precision Approach Radar
Pilot Flying
Pilot in Command
Pilot Monitoring
Pilot’s Operating Handbook
Principal Operations Inspector
MAP
MASPS
MDA
MEL
MLS
MMEL
MSpec
NAS
NDB
NSP
OpSpec
OUSD
PAR
PF
PIC
PM
POH
POI
A-II
07/26/13
AC 90-106A
Appendix A
Acronym
Definition
QRH
REIL
RFSD
RII
RNAV
RTS
RVR
SCO
SDF
SIAP
SIC
SM
SMGCS
STC
SVS
TC
TCH
TDZ
TDZE
TERPS
TSO
VOR
VDA
VDP
VFR
VGSI
VHF
VNAV
Quick Reference Handbook
Runway End Identifier Lights
Regional Flight Standards Division
Required Inspection Item
Area Navigation
Return to Service
Runway Visual Range
Special Certification Office
Simplified Directional Facility
Standard Instrument Approach Procedure
Second in Command
Statute Mile
Surface Movement Guidance and Control System
Supplemental Type Certificate
Synthetic Vision System
Type Certificate
Threshold Crossing Height
Touchdown Zone
Touchdown Zone Elevation
U.S. Standard for Terminal Instrument Procedures
Technical Standard Order
Very High Frequency Omni-Directional Range Station
Vertical Descent Angle
Vertical Descent Point
Visual Flight Rules
Visual Glide Slope Indicator
Very High Frequency
Vertical Navigation
A-III
07/26/13
AC 90-106A
Appendix B
Appendix B. Definitions
For the purpose of operations under this AC, appendix B provides the following definitions:
1.
Aircraft Certification Office (ACO). The aircraft certification directorate’s engineering
operational element. This office administers and secures compliance with agency
regulations, programs, standards, and procedures governing the type design of aircraft,
aircraft engines, and propellers. The office offers certification expertise on investigating and
reporting aircraft accidents, incidents, and service difficulties. The term “ACO” refers to an
Engine Certification Office (ECO), the Rotorcraft Certification Office (RCO), the Special
Certification Office (SCO), the Aircraft Certification Office (ACO), and all other ACOs.
2.
Aircraft Evaluation Group (AEG). A Flight Standards Service (AFS) field element that
helps support the certification and operational suitability determinations of new and
modified type-certificated products. AEGs are the primary AFS liaison between Flight
Standards elements and the accountable aircraft certification directorate and/or the
manufacturers. AEGs may be colocated with an accountable directorate or one of its
elements.
3.
Amended Type Certificate (ATC). An ATC is issued when the holder of the type
certificate receives FAA approval to modify an aircraft design from its original design. An
amended type certificate approves not only the modification, but also how that modification
affects the original design.
4.
Certificate-Holding District Office (CHDO). A Federal Aviation Administration (FAA)
Flight Standards District Office (FSDO), certificate management office (CMO),
International Field Office (IFO), or Certificate Management Unit (CMU) assigned by the
FAA to have oversight responsibility for a particular certificate holder.
5.
Enhanced Flight Vision System (EFVS). An installed aircraft system that uses an
electronic means to provide a display of the forward external scene topography (the
applicable natural or manmade features of a place or region especially in a way to show their
relative positions and elevation) through the use of imaging sensors, such as FLIR,
millimeter wave radiometry, millimeter wave radar, or low-light level image intensification.
The EFVS sensor imagery and required aircraft flight information and flight symbology is
displayed on a HUD, or an equivalent display, on which the imagery and symbology is
clearly visible to the PF in his or her normal position with the line of vision looking forward
along the flight path. An EFVS includes the display element, sensors, computers and power
supplies, indications, and controls.
6.
Enhanced Flight Visibility. The average forward horizontal distance from the cockpit of an
aircraft in flight at which a pilot using an EFVS may clearly distinguish and identify
prominent topographical objects by day or night.
7.
Enhanced Flight Vision System I. The installed EFVS has been demonstrated to meet the
criteria for AC 20-167A for EFVS I to be used for instrument approach operations from
DA/DH or MDA down to 100 ft height above TDZ elevation.
B-I
07/26/13
AC 90-106A
Appendix B
8.
Enhanced Flight Vision System II. The installed EFVS has been demonstrated to meet the
criteria for AC 20-167A for EFVS II to be used for instrument approach and landing
operations that rely on sufficient visibility conditions to enable unaided rollout and to
mitigate for loss of EFVS function. An EFVS that meets the certification criteria for EFVS
II also meets the certification criteria for EFVS I.
9.
Enhanced Vision System (EVS). An electronic means to provide the flightcrew with a
sensor-derived or -enhanced image of the external scene (e.g., millimeter wave radar or
FLIR).
10. Flight Standardization Board (FSB). A designated group of operations inspectors who
determine type rating, certification, and training requirements for new or modified aircraft.
11. Head-Up Display (HUD). An aircraft system that provides head-up guidance to the pilot
during flight. It includes the display element, sensors, computers, power supplies,
indications, and controls. It may receive inputs from an airborne navigation system or flight
guidance system. This system allows the pilot to look for the outside visual references in the
same location as they appear in the EFVS image.
12. Head-Down Display (HDD). A display or suite of displays that provide control,
performance, and navigation information that is presented to the pilot on conventional headdown instrumentation, or integrated electronic flight displays.
13. Glide Slope. Vertical guidance for an aircraft during approach and landing.
14. Master Minimum Equipment List (MMEL). A list of equipment that the FAA has
determined may be inoperative under certain operational conditions and still provide an
acceptable level of safety. The MMEL contains the conditions, limitations, and procedures
required for operating the aircraft with these items inoperative. The MMEL is used as a
starting point in the development and review of an individual operator’s minimum
equipment list (MEL).
15. Minimum Equipment List (MEL). The MEL is a list derived from the MMEL for a
particular make and model of aircraft by an individual operator. The operator’s MEL takes
into consideration the operator’s particular aircraft configurations, operating procedures, and
conditions with certain inoperative equipment.
16. Natural Vision. The means by which a pilot observes objects without benefit of any visionenhancing technology (except personal corrective lenses).
17. Nonprecision Approach Procedure. A standard instrument approach procedure (IAP) for
which no electronic glideslope (GS) information is provided.
18. Precision Approach Procedure. A standard instrument approach procedure (SIAP) for
which an electronic GS information is provided, such as instrument landing system (ILS)
and precision approach radar (PAR).
B-II
07/26/13
AC 90-106A
Appendix B
19. Special Instrument Approach Procedure. An IAP authorized for use only by an air carrier
or some other segment of the aviation industry that is not published in the Federal Register
and identified as a “Special Procedure.” Special Procedures may be developed for public or
private use based on aircraft performance, aircraft equipment, or crew training, and may
require the use of landing aids, communications, or weather services not available for public
use.
20. Standard Instrument Approach Procedure (SIAP). An IAP promulgated under Title 14
of the Code of Federal Regulations (14 CFR) part 97.
21. Straight-In Nonprecision Approach. An approved IAP in which the final approach course
alignment and descent gradient permits authorization of straight-in landing minima. The
angle of convergence of the final approach course and the extended runway centerline will
not exceed 30 degrees (15 degrees for Area Navigation (RNAV)/global positioning system
(GPS)) and the point of intersection will normally be within 5,200 feet outward from the
runway threshold. The maximum descent gradient is 400 ft/NM.
22. Straight-In Precision Approach. An approved IAP in which the final approach course
alignment does not exceed 3 degrees of the extended runway centerline.
23. Supplemental Type Certificate (STC). An STC is issued for a major design change to a
type certificate (TC) when the change is not so extensive as to require application for a new
TC, except that the holder of a TC for a product may apply for amendment of the original
TC.
24. Synthetic Vision. A computer-generated image of the external scene topography from the
perspective of the flightdeck that is derived from aircraft attitude, high-precision navigation
solution, database of terrain, obstacles, and relevant cultural features.
25. Synthetic Vision System (SVS). An electronic means to display a synthetic vision image of
the external scene topography to the flight crew. An SVS display does not provide an
independent, real-time source of forward scene information.
26. Type Certificate (TC). A design approval that certifies that an applicant’s design for a new
(or new model) aircraft, engine, or propeller meets the minimum FAA requirements. It
includes the type design, the operating limitations, the type certificate data sheet, the
applicable regulations the type design was certified to, and any other conditions or
limitations required in 14 CFR, Subchapter C.
27. Touchdown Zone (TDZ) Elevation (TDZE). The highest elevation in the first 3,000 feet of
the landing surface. TDZE is indicated on the IAP chart when straight-in landing minimums
are authorized.
B-III
Appendix C. Related Publications
C-1. Related Publications.
a. Federal Aviation Administration Documents:
1. AC 20-167, Airworthiness Approval of Enhanced Vision System, Synthetic Vision
System, Combined Vision System, and Enhanced Flight Vision System Equipment
2. AC 25-11A, Electronic Flight Deck Displays
3. AC 91-16, Category II Operations General Aviation Airplanes
4. AC 120-28, Criteria for Approval of CAT III Weather Minima for Takeoff, Landing,
and Rollout
5. AC 120-29, Criteria for Approval of Category I and Category II Weather Minima for
Approach
6. AC 120-57, Surface Movement Guidance and Control System
7. AC 120-71, Standard Operating Procedures for Flight Deck Crewmembers
8. AC 120-76, Guidelines for the Certification, Airworthiness, and Operational
Approval of Electronic Flight Bag Computing Devices
9. FAA Order 8000.94, Procedures for Establishing Airport Low-Visibility Operations
and Approval of Low-Visibility Operations/Surface Movement Guidance and Control
System Operations
10. FAA Order 8900.1, Flight Standards Information Management System (FSIMS)
11. Flight Standardization Board (FSB) reports:
http://fsims.faa.gov/PICResults.aspx?mode=Publication&doctype=FSB%20Reports.
12. National Simulator Program (NSP) information:
http://www.faa.gov/about/initiatives/nsp/.
NOTE: You may obtain ACs and Policy Memorandums by clicking on the
link “Regulatory and Guidance Library” on the FAA public Web site:
http://www.faa.gov/.
b. RTCA, Inc. Documents
1. DO-315, Minimum Aviation System Performance Standards (MASPS) for Enhanced
Vision Systems, Synthetic Vision Systems, Combined Vision Systems, and Enhanced
Flight Vision Systems.
C-I
07/07/13
AC 90-106A
Appendix F
2. DO-341, Minimum Aviation System Performance Standards (MASPS) for an
Enhanced Flight Vision System to Enable All-Weather Approach, Landing and RollOut to a Safe Taxi Speed
c. Society of Automotive Engineers (SAE) International.
1. AS 5703, Minimum Performance Standard for Enhanced Vision System.
2. AS 8055, Minimum Performance Standard for Airborne Head Up Display (HUD).
C-2. How to Get Publications.
a. Order copies of 14 CFR, parts from the Superintendent of Documents, Government
Printing Office, P.O. 979050, St. Louis, MO 63197. For general information, telephone (202)
512-1800 or fax (202) 512-2250. You can order copies online at www.access.gpo.gov. Select
“Access” then “Online Bookstore.” Select “Aviation,” then “Code of Federal Regulations.”
b. Order copies of FAA advisory circulars from the U.S. Department of Transportation,
Subsequent Distribution Office, M-30, Ardmore East Business Center, 3341 Q 75th Avenue,
Landover, MD 20785. You can also get copies from our FAA website at www.airweb.faa.gov or
www.faa.gov.
c. You can find a current list of technical standard orders on the FAA Internet website
Regulatory and Guidance Library at www.airweb.faa.gov/rgl. You will also find the Technical
Standard Order (TSO) Index of Articles at the same site.
d. Order copies of RTCA documents from RTCA, Inc., 1828 L St., NW, Suite 805,
Washington, DC 20036, telephone (202) 833-9339, Fax (202) 833-9434, or website:
www.rtca.org.
e. Order copies of SAE documents from SAE World Headquarters, 400 Commonwealth
Drive, Warrendale, PA 15096-0001, USA, telephone: (877) 606-7323, or website:
http://www.sae.org.
C-II