Navigation Applications perspective on ADQ
ADQ Implementation Workshop
Lendina Smaja
Navigation specialist
28/05/2013
Table of Content

Transition to PBN

Importance of Data quality

Focus on PBN Approaches (RNP APCH)

Activities prior to procedure publication

Precision approach example: GBAS/GLS Data Integrity Management

Conclusions
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Transition to PBN
B
A
• The aircraft’s RNAV system uses positioning sensors such as GNSS (or DME) to determine its
position and establish the required track normally using navigation data from an on-board navigation
database
• Today, PBN distinguished between RNAV and RNP applications (RNP requires on-board
performance monitoring and alerting) navigation specifications for application in the oceanic, en
route, terminal and approach phases of flight
• Similarly, GBAS which is a precision approach (xLS) relies on navigation data for defining the final
approach path
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The impact of bad data
Runway
Data Quality




The successful and safe implementation of PBN and xLS applications depends upon high integrity
navigation data.
The more demanding the application, the more important this becomes; particularly terminal and
approach operations.
There is a need to ensure the originated data is accurate and sufficiently precise
There is a need to ensure the integrity of data within the data chain (depicted below)
Data Origination
(surveyor/designer)
Data Publication
(States)
Nav Database
Providers
Data Packers
OEMs
Aircraft Operators
Coding
AIP
Nav DB
If unclear or ambiguous procedure
description
Failure to implement adequate quality
procedures
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Aircraft fly
wrong tracks
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Focus on PBN Approach (RNP APCH)
LATERAL dimension
IAF
VERTICAL dimension
IF
FAF
FAF
Decision Height
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PBN procedures are coded as a series of waypoints and legs which define specific nominal
tracks
The Final Approach record (FAS DB) of RNP APCH is stored in each and every NAV
database of the aircraft flying this procedure.
CONCERN: higher risk for data corruption…
Data Formatting
Data Origination
(surveyor/designer)
Data Publication
(States)
Nav Database
Providers
AIP


Coding
(ARINC 424)
Aircraft Operators
Nav DB
PANS-OPS require electronic transfer of FAS DB. CONCERN: any electronic file created by
procedure designer will be transformed before entering the NAV database…
Procedure design propose a coding (legs). CONCERN: what gets finally coded in NAV database
reveal to be different sometimes (translation to ARINC 424 and then to avionic specific format)…



Data Packers
OEMs
Procedure designers need to understand RNAV system limitations
Same ARINC 424 legs can be differently executed in aircraft types
FAS DB is not the only data required for coding in the database. CONCERN on the format for
publication and transfer of these data…
Activities prior to procedure publication

Ground Validation
 Obstacle Clearance
 Charting
 Coding
 Flyability

Flight Inspection
 Infrastructure

Flight Validation
 Obstacle Verification (optional)
 Flyability (workload, charting, manoeuvring)
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Activities prior to approach procedure publication (cont.)
Data Origination
(surveyor/designer)
Data Publication
(States)
Nav Database
Providers
Data Packers
OEMs
Validate the
procedure
here?
Aircraft Operators
Usually flight
validation is
done with preproduction
navigation
databases
•Some issues:
•Flight validation: What NAV database to use for a flight validation?
- Should this be an official database? CONCERNS on the chronology (publication before procedure is
actually checked) or on extra cost (to get an pre-production nav. database outside of the normal publication
process)
- What is the completeness of this check? CONCERN is what is validated is also what is coded (other
coding available on the market)
•Validation tools: How should these tools be validated
Precision approach example: GBAS/GLS Data Integrity Management

GBAS is the first precision approach system to rely on aeronautical data for generation of the
precision approach path. The data quality (accuracy, confidence level and integrity) has a direct
impact on the position error on the approach
Airport survey
Procedure Design
•Reference Path Id.
•Horizontal Reference Datum
•GBAS Ground Station info.
•All waypoints of procedure
Initial segments of the
procedures before final
(FAS)
Approach Plates
FAS DB creation
AIP Data
Upload in GBAS
Ground Station
Data on Aircraft
NAV DB
Flight validation
•Final Approach Segment (FAS)
•FASVAL and FASLAL
VDB Transmission
Data flow for GBAS
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Safety Critical Data Chain for GBAS


Determination of WGS84 coordinates for

Runway coordinates (threshold – LTP/FTP, FPAP)

GNSS reference antenna phase centre coordinates
Procedure design

Typically uses threshold coordinates of the runway as input

Outputs FAS data block file – Cyclic Redundancy Check (CRC) wrapped- in binary format for each precision
approach

Procedure publication (AIP)

Transfer and Load into the GBAS Ground Station

GBAS Ground & Flight Testing (ICAO Doc.8071)


Use VDB or GBAS receiver to check the data content and CRC

Fly all procedures
VDB transmission of data to the aircraft

Ground station monitors data content and CRC internally

Airborne receiver checks FAS data file and CRC
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GBAS/GLS FAS Data Block

The FAS Data Block contains the safety critical information for a precision approach

The FAS Path is a line in space defined by:

Landing threshold point/fictitious threshold point (LTP/FP)

Flight path alignment point (FPAP)

Threshold crossing height (TCH)

Glide path angle (GPA)

The FAS data block is protected by CRC

The transfer of FAS DB to the GBAS ground station should transferred electronically via media or
via network
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Conclusions
 Navigation with respect to waypoints and not beacons
The high integrity navigation data is of utmost importance for the
implementation of PBN and xLS applications.
 The ADQ IR Mandate and EUROCONTROL Data Origination
Specification contribute to improve the quality of navigation data,
thus facilitating future applications
 The activities prior to instrument flight procedures publication still
need additional guidelines to be harmonised
Questions?
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