Validate ATC Validated ATS procedures to support the
procedures services provided for ADS-B equipped aircraft
Project ICAO SASPOperational Use of ADS-B in Non Radar Airspace
Hazard No. 37 Altitude Display
Generic Description Possibility of controllers confusing Barometric and Geometric levels on display
Hazard Cause/Initiating Events Geometric level is displayed if the aircraft is at or below the transition altitude AND either Barometric Level is not available or the aircraft is not in a QNH defined area
Geometric Level displayed in a different colour to distinguish it from Barometric Level (displayed in
Initial Risk Residual
Risk
Likelihood Occasional Occasional
Consequence Cat 4 Cat 4
Risk D D
Existing Mitigation
track colour)
Geometric level will only be used for separation if checked within 200 ft of pilot report. This issue will be covered
during training.
Safety Requirement Details
Validate ATC Validated ATS procedures to support the procedures services provided for ADS-B equipped aircraft
Use of Barometric and Ensure ATC procedures and training Geometric levels adequately cover the use of Barometric and Geometric levels in ADS B
Project ICAO SASPOperational Use of ADS-B in Non Radar Airspace
Hazard No. 38 Altitude incorrect and not checked
Generic Description If separate pressure encoders are used for the ADS-B and SSR transponders, then there will be a requirement to check the altitude display with the display in the cockpit whenever the aircraft initially enters either ADS-B or radar airspace
Hazard Cause/Initiating Events Separate pressure encoders used for ADS-B and SSR transponders, hence aircraft altitude source depends on type
of
surveillance being used.
Initial Risk Residual
Risk
Likelihood
Consequence
Risk
Existing Mitigation
Safety Requirement Details
Project ICAO SASPOperational Use of ADS-B in Non Radar Airspace
Hazard No. 39 Track couples to wrong Flight Plan
Generic Description 24-bit code and registration in Flight Plan is for another aircraft. The result is that an aircraft's ADS-B track may couple to the wrong Flight Plan.
Hazard Cause/Initiating Events 24-bit code and registration in Flight Plan is for another aircraft. Could be a result of an aircraft substitution that is not followed by cancellation and re-issue of flight plan.
Initial Risk Residual
Risk
Likelihood
Consequence
Risk
Existing Mitigation
Safety Requirement Details
APPENDIX 3
AMENDMENT PROPOSAL FOR PANS-ATM Doc 4444
