1. GNSS IFR Installations & Approvals Ron Doggett Aircraft Certification Unit 1

2. Contents  GNSS AC Development  Installation Requirements and Issues  Autopilots & Instrument Switching  Other Requirements  Flight Testing  Future Requirements 2

3. GNSS AC Development  Part 19 Sub Part D out of date.  GNSS AC is an interim solution until Part 91 Rules are amended by PBN implementation.  Exemptions are required to Part 19 to recognise GNSS (GPS) maturity and enable AC provisions.  CAA 2129 will have operational capability added as Part B.  Goal: draft for public comment by the end of the year. 3

4. Installation Requirements  Equipment must be approved for Level 1 (TSO).  Installation must comply with FAA AC 20-138A Airworthiness Approval Of Global Navigation Satellite System (GNSS) Equipment requirements.  TSO C129a equipment requires a pressure altitude input (from an approved source). Recommended for TSO C129 equipment.  Relevant airworthiness requirements must be met. 4

5. Human Factors & System Safety Perception … Pilots are cool dudes who can hack anything… - including dealing with bad designs - 5

6. Human Factors & System Safety Reality … Design engineers must design for the “inverse” of the perception! 6

7. Installation Human Factors  System safety and human factors is not about how easy it is on a good day, but how hard it is to get it wrong on a bad day. Remember - The Domino Theory and Reason’s Swiss cheese are extensions to Murphy’s law – If it can happen, it will and at the worst possible time. 7

8. Installation Points  System(s) must be integrated with flight instruments.  Two crew aircraft require integration with both pilot’s flight instruments (FAR 23.1321).  CDUs must be clearly visible under all lighting conditions, and be easily reached.  Dual antenna installations require lateral separation.  Lit panels need to be properly modified. 8

9. Autopilots & Instrument Switching  Interface to flight instruments and autopilots has a high human factors risk, particularly for switching and pilot workload.  Clever switching is behind the panel, not in front.  Switching systems must be independently powered.  Autopilots must maintain the aircraft within half the CDI scale on straight segments.  Adjusting CDI scaling from default values for autopilot gain is not permitted. 9

10. Poor Installation Examples 10 Pilot ViewActual Display Control panels also need to be modified.

11. Other Requirements  Steering interfaces need output to input compatibility analysis, particularly for analogue systems.  Electrical Load Analysis is required for the aircraft.  GNSS installations are becoming essential systems.  The complete installation must be considered in the assessment, including interfaces to other systems.  Flight Manual Supplements need to address autopilot coupling, if applicable.  ICAW are not optional! 11

12. Flight Testing  A formal flight test plan is required.  A risk assessment must be carried out with any identified risks being mitigated or minimised.  Installations that change the instrument arrangement or couple to the autopilot require flight test and pilot workload assessment.  Production installations require flight validation only.  Pilots need to be experienced and rated on the aircraft and the equipment (Refer AC 19-1). 12

13. Flight Test Plans  Preamble identifies:  Changes made to the aircraft, prerequisites, personnel requirements, flight profile, etc.  Tests procedures state:  Test objective and pass / fail criteria.  Identifies each process step for the test.  Identifies any data to be recorded by the crew.  Short or generic test specifications are not acceptable. 13

14. Operational Approvals  TSO C129 systems require FAA Order 8110.60 approval for oceanic / remote continental use.  For dual installations, the software configuration must be the same.  Operational approval for an aircraft is endorsed on the CAA 2129.  Foreign STC installations will be accepted per Part 21.  Foreign and NZ modifications require CAA inspection and flight test. 14

15. Future Requirements  NZ will transition to area navigation with high reliance on GNSS.  Requirements will be defined during PBN implementation activity.  Air transport IFR GNSS will require dual systems fully integrated.  TSO C129 systems will require retention of legacy navigation systems; TSO C145/146 may not. 15

16. 16 Any questions?