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767 LOC Backcourse

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FCOM 2 pg. 4.10.13
Personal note: You MUST push B/CRS switch first, then LOC
3 Backcourse (B/CRS) Switch
Push – (Must be used concurrently with LOC switch), arms or engages AFDS in
B/CRS mode as follows:
B/CRS appears on each FMA prior to localizer capture.
• AFDS is armed to capture and track inbound on backcourse of localizer
• capture point varies based on range and intercept angle
• initial roll modes; LNAV, HDG SEL or HDG HOLD remain engaged
until B/CRS capture
• before localizer capture, pushing the LOC switch a second time disarms
both the LOC and B/CRS modes. Pushing only the B/CRS switch a
second time, disarms the B/CRS mode but the LOC mode remains
armed
B/CRS appears on each FMA after localizer capture.
• AFDS tracks inbound on backcourse
• if the LOC switch is selected and localizer is captured before B/CRS
switch is pushed, AFDS will track the localizer front course (outbound)
and B/CRS cannot be selected
• G/S, FLARE and ROLLOUT functions are not available
Note: The B/CRS mode is a single autopilot function only. Multiple autopilots
cannot be engaged with this mode.
------------------------------------------------------------------------------------------------------------FCOM 1 pg. NP .21 .51 & NP .21 .52
Landing Procedure - Non-Precision VNAV/Vertical Speed
Approach
Note: ATI crews may utilize the VNAV MCP mode for vertical path
guidance to fly a Non-Precision Approach down to an MDA +
50’ Derived Decision Altitude (DDA). ATI does not have
OPSPEC approval to request, accept, or initiate, a Non-Precision
Approach Procedure that includes a VNAV DA(H) in lieu of an
MDA(H). These approaches are characterized by a Glide Path
angle depicted in the FMC down to a Decision Altitude.
Non-Precision Approaches include:
VOR/DME RNAV, NDB, NDB/DME, LOC, LOC BC, LOC/BC/DME,
LOC/DME, NBD, NBD/DME, SDF, VOR, VOR/DME, VOR/DME/LOC,
LDA, and RNAV (GPS)
Use the autopilot during the approach to give:
• Autopilot alerts and mode fail indications.
• More accurate course and glide path tracking.
• lower RNP limits
Continuous Descent Final Approach (CDFA) Technique will be employed
for flying the final approach segment (FAS) of the instrument approach
procedure (IAP) using either Baro-VNAV as a reference or Vertical Speed
(VS) FMS functions with vertical flight path deviation guidance.
This procedure is not authorized using QFE.
FCOM 1 pg. NP .21 .51 & NP .21 .52 (USE LNAV for a B/CRS)
How To Set Up A "LOC BC" (With HSI)
If you're lucky enough to fly with a horizontal situation indicator (HSI), flying LOC BC approaches
gets significantly easier. The HSI combines a heading indicator with CDI needles. As long as you
tune the front course for the localizer, you won't get reverse sensing. When configured
properly, you can fly the LOC BC approach with normal sensing, and fly "to the needle" like you
do in all other navigation.
For example, if you were flying the LOC BC to runway 17R in Grand Forks, instead of dialing the
back course of 174 degrees, you'd dial the front course of 354 degrees, and fly to the needle to
navigate the approach.
hsi back course
Flying The LOC BC Approach
Once you're established on a LOC BC approach, flying is as simple as any non-precision
approach. You'll reference step down fixes and DME before leveling off at your minimum
descent altitude (MDA).
Unlike most localizer approaches, expect a missed approach point on a LOC BC approach to be
located more than half a mile before the runway. The reason? It would be impossible to fly all
the way to the runway threshold at MDA on a LOC BC approach. As you get closer and closer to
the localizer antenna, it becomes increasingly difficult to stay on course due to increasing signal
sensitivity. Since the localizer system you're using for the back course is located near the
runway threshold, as opposed to the departure end, the missed approach point is farther away
from the runway.
missed approach point
You will be making a manual descent to the MDA as there is no glide path guidance with a Back
Course approach.
The FAA offers a warning about flying back course approaches: "False glide slope signals may
exist in the area of the localizer back course approach which can cause the glide slope flag
alarm to disappear and present unreliable glide slope information. Disregard all glide slope
signal indications when making a localizer back course approach unless a glide slope is specified
on the approach and landing chart."
Using An Autopilot? PUSH THE "BACK COURSE BUTTON"
When you fly an autopilot-coupled LOC BC approach, ALWAYS push the "back course button" if
there's one installed for your autopilot system. By pushing this button, you're telling the
autopilot to turn inbound on the back course instead of outbound. Here's the scenario...
If you're flying with an HSI, you should have tuned the front course for the localizer to avoid
reverse sensing. Your CDI needle will thus point away from the runway. If ATC clears you to
track inbound on the localizer and you click "NAV" mode on the autopilot, the autopilot will
turn the wrong way, outbound!
The autopilot doesn't know that you're flying a back course approach. If you've engaged NAV
mode, it will intercept and fly the course you've set. By pushing the "BC" button, you're telling
the autopilot to track inbound on the back course, which will avoid you making an inadvertent
and potentially dangerous outbound turn.
autopilot back course button
Think you're ready to fly the approach? Take this quiz: Could You Fly This Localizer Back Course
Approach?
How many times have you had to fly a LOC BC approach? Tell us in the comments below.
==============================================================================
==================
The Localizer Back Course
The localizer antenna array is located at the far end of the runway, away from the approaching
aircraft. Its antennas are arranged and manufactured in such a way to transmit a narrow signal
on the runway approach path. That localizer signal is so accurate that with its guidance, along
with the glide slope signal, an aircraft can safely land when the visibility is zero and when the
ceiling is zero.
However, the Localizer antenna array also radiates a narrow signal beam in the opposite
direction of the approach path. That signal is called the Localizer Back Course.
A prime advantage of the Back Course is that the airport gets it for free. It need only be tested
and certified to become available to pilots "coming in from the other direction." Approach
plates are published specifically for the localizer back course.
Too many pilots shy away from a back course approach because of the reverse sensing of the
needle. On the back course, one must correct drift with a turn away from the needle. Keep your
wits about you, though, and you will quickly master the reverse sensing needle.
The Back Course localizer approach is a non-precision approach. There is no glide-path guidance
with it. Glide-path signals from the front course may be received while on the back course, but
you should ignore them.
Crossing the IAF (Initial Approach Fix) begin your descent. Remember, this is a manual descent
to the MDA as there is no glide-path guidance. Upon reaching the MDA you may fly that
altitude until reaching the DME of the Missed Approach Point (MAP), at which you must see the
runway for landing OR fly the missed approach.
===========================================================================
FCOM 2 pg. 4.10.13
Personal note: You MUST push B/CRS switch first, then LOC
3 Backcourse (B/CRS) Switch
Push – (Must be used concurrently with LOC switch), arms or engages AFDS in
B/CRS mode as follows:
B/CRS appears on each FMA prior to localizer capture.
• AFDS is armed to capture and track inbound on backcourse of localizer
• capture point varies based on range and intercept angle
• initial roll modes; LNAV, HDG SEL or HDG HOLD remain engaged
until B/CRS capture
• before localizer capture, pushing the LOC switch a second time disarms
both the LOC and B/CRS modes. Pushing only the B/CRS switch a
second time, disarms the B/CRS mode but the LOC mode remains
armed
B/CRS appears on each FMA after localizer capture.
• AFDS tracks inbound on backcourse
• if the LOC switch is selected and localizer is captured before B/CRS
switch is pushed, AFDS will track the localizer front course (outbound)
and B/CRS cannot be selected
• G/S, FLARE and ROLLOUT functions are not available
Note: The B/CRS mode is a single autopilot function only. Multiple autopilots
cannot be engaged with this mode.
------------------------------------------------------------------------------------------------------------FCOM 1 pg. NP .21 .51 & NP .21 .52
Landing Procedure - Non-Precision VNAV/Vertical Speed
Approach
Note: ATI crews may utilize the VNAV MCP mode for vertical path
guidance to fly a Non-Precision Approach down to an MDA +
50’ Derived Decision Altitude (DDA). ATI does not have
OPSPEC approval to request, accept, or initiate, a Non-Precision
Approach Procedure that includes a VNAV DA(H) in lieu of an
MDA(H). These approaches are characterized by a Glide Path
angle depicted in the FMC down to a Decision Altitude.
Non-Precision Approaches include:
VOR/DME RNAV, NDB, NDB/DME, LOC, LOC BC, LOC/BC/DME,
LOC/DME, NBD, NBD/DME, SDF, VOR, VOR/DME, VOR/DME/LOC,
LDA, and RNAV (GPS)
Use the autopilot during the approach to give:
• Autopilot alerts and mode fail indications.
• More accurate course and glide path tracking.
• lower RNP limits
Continuous Descent Final Approach (CDFA) Technique will be employed
for flying the final approach segment (FAS) of the instrument approach
procedure (IAP) using either Baro-VNAV as a reference or Vertical Speed
(VS) FMS functions with vertical flight path deviation guidance.
This procedure is not authorized using QFE.
FCOM 1 pg. NP .21 .51 & NP .21 .52 (USE LNAV for a B/CRS)
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