AMC 20-XX presentation Airworthiness and Operational approval for RNAV (GNSS) Approach

1. AMC 20-XX presentationAirworthiness and Operational approval forRNAV (GNSS) Approach B. RABILLER OST Meeting 21st September 05

2. Contents • Introduction • AMC 20-XX Scope • System Description • Operational Criteria • Flight Crew training • Navigation Database Management. • Aerodrome competence and operator verification • Conclusion

3. Introduction (1/2) • AMC 20-XX is built on existing guidance material • EASA AMC 20-4 (TGL 2) for Basic RNAV • JAA TGL No. 10 for Precision RNAV • Contains both airworthiness and operational criteria • Completes family of RNAV guidance document (AMC or Leaflet) from departure to final approach • This AMC addresses only navigation systems based on GNSS technology. • Guidance on use of GPS for approach operations (contained within EASA AMC 20-5/JAA TGL 3) to be superseded by AMC 20-XX material

4. Introduction (2/2) • 2 AMCs are proposed to address RNAV Approaches operation: • AMC 20-XX “Airworthiness and operational approval for RNAV (GNSS) approach operation» • AMC 20-XZ “Airworthiness and operational approval for RNP approach operation»  • Apart from the RNP specifics, AMC 20-XX and AMC 20-XZ have common flight crew operating techniques.

5. AMC 20-XX Scope • Objective is to address approach operation : • having stand-alone “T” or “Y” transition to the final approach segment • With a straight in segment following a P-RNAV arrival • Applicable to: • stand-alone GNSS/map equipments (e.g TSO C 129a receiver) • and FMS without RNP-RNAV functionality • Defines criteria for the Lateral navigation part only as a first step. • Use of Baro VNAV on NPA and APV (Baro and SBAS) are not addressed in this document. • Should not be used for RNP 0.3 approval.

6. System Description • A lateral navigation system based on GNSS. • Accuracy of +/- 1Nm laterally for initial and intermediate approach segment and +/- 0.3 NM for the final segment. • AMC 20-XX describes all RNAV required function (deviation display, nav data base, Arinc 424 path terminator, integrity alert,…). • AMC 20-XX describes recommended function : • Autopilot/ FD coupling. • Enhance navigation display to support lateral situational awareness, navigation monitoring and flight plan verification. • Dual system installation is not requested for RNAV(GNSS) approach from an airworthiness point of view.

7. Operational criteria (1/2) • Consistent with already approved operational RNAV criteria (e.g TGL 10 for PRNAV). • Normal procedure • RNAV Approach should be GNSS one. • Approach loaded from the nav data base has been validated by the operator. • Prediction of the integrity availability (e.g RAIM) to be checked. • Check if a specific request exists for having a dual installation for this approach. • Missed approach procedure should be flown in accordance with the published procedure and can be based on conventional means (VOR, NDB), on RNAV or on Dead Reckoning.

8. Operational criteria (2/2) • Prior to commencing the procedure • Reasonableness check of the loaded procedure (track, distance,…) • For multisensor system, check GNSS sensor is active. • During the procedure • Final approach trajectory should be intercepted before the FAF. • Route modification (e.g. DIR TO FAF) may be requested by the ATC. • Approach mode is activated before FAF (typically 2 Nm before FAF) • Description of failures leading to a missed approach.

9. Flight Crew training • To conduct safely RNAV (GNSS) approach, each pilot should receive appropriate: • training • briefings, • guidance material • This should cover normal and abnormal procedures. • Standard training events such as proficiency check should include GNSS approach. • The operator should determine what constitutes a qualified crew.

10. Navigation Database Management • Navigation database Integrity is demonstrated if there is a LOA type 2 covering the airborne navigation system and its navigation database • if it is not the case the operator should develop an alternative method (manual verification, use of specific tools…) and demonstrate its acceptability to the Authority • Precaution in order to address the database loading is also defined (load nav database P/N compatible with the navigation system model and the aircraft type).

11. Aerodrome competence and Operator verification • Operator should determine the operational characteristic of the approach procedure to be flown (e.g hilly environment, missed approach trajectory with turns at low altitude, adequate knowledge for the aerodrome access, adequate aerodrome competence qualification,…). • Based on this assessment: • Appropriate information shall be given to the crew • Crew should have a validated competence if aerodrome access request it. • It is anticipated that in most cases no specific competence should be requested because AMC 20-XX is addressing only RNAV(GNSS) approaches designed with straight segment

12. Conclusion • AMC 20-XX was developed to address an operational need in Europe. • AMC 20-XX provides clear airworthiness and operational criteria for RNAV(GNSS) approach operation. • AMC 20-XX is consistent with other existing RNAV operational procedure practises (e.g PRNAV, BRNAV, RNP approach). • AMC 20-XX is more detailed than the approach part of AMC 20-5/ TGL 3 and reflect today operational environment.

13. Future Work • Future Version of AMC 20-XX should include APV criteria (Baro-VNAV and SBAS). • Discussion with JAA OPS and AWOSG is necessary for the Baro-VNAV aspect in particular to be consistent with NPA-OPS 41 CDFA concept. • Use of Baro VNAV on NPA . • MDA versus DA • …….

14. Discussion