RNAV AIRBORNE SYSTEM AIRWORTHINESS REGULATION AND CERTIFICATION ISSUES

1. RNAV AIRBORNE SYSTEMAIRWORTHINESS REGULATION AND CERTIFICATION ISSUES B. RABILLER / French DGAC SFACT/ Aircraft Certification Office ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR

2. INTRODUCTION PRNAV RNP 5 GPS LNAV/VNAV BRNAV RNP 0.3 INS RNP-RNAV RNP 10 DME-DME VOR/DME RNAV IS A COMPLEX WORLD !

3. INTRODUCTION • TO DESCRIBE THE AIRCRAFT CERTIFICATION PROCESS • TO DESCRIBE RNAV IMPLEMENTATION TROUGH TWO EXAMPLES FROM AN AIRCRAFT POINT OF VIEW • BRNAV FOR ENROUTE CONTINENTAL • PRNAV FOR TERMINAL AREA • TO TALK A LITTLE BIT ABOUT RNP CONCEPT

4. INTRODUCTIONRNAV SYSTEM FOR GENERAL AVIATION(EXAMPLE) External annunciator GPS antenna NAV WPT GNSSMSG APPR GPS Receiver Aircraft interfaces (Power, Altitude,..). HSI (Horizontal Situation Indicator)

5. INTRODUCTIONRNAV SYSTEM FOR AIR TRANSPORT AIRCRAFT (EXAMPLE) External annunciator GPS antenna NAV WPT FMS MSG APPR ADI Via Autopilot MCDU GPS Sensor FMS Computer (Flight Management System) Others sensor : IRS, VOR,DME,.. HSI Aircraft interfaces (Altitude,..).

6. AIRCRAFT CERTIFICATION PROCESS ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR

7. Airworthiness general Approval Process A SAFETY Issue • A process permitting to issue a Certificate of Airworthiness for an aircraft. Yes Is my aircraft airworthy? Aircraft manufacturer C of A Compliance with Airworthiness regulation Authority (JAA,FAA,...)

8. Airworthiness general Approval ProcessType Certificate (TC) • For a new aircraft Model. • A dedicated certification team at Authority level. • Certification basis issued for this aircraft. • Multidiscipline program (engine, structure, cabin safety, avionics, electricity,...) • At the End TC is issued with a C of A and an aircraft flight manual is approved • This is not an operational approval!

9. Airworthiness general Approval ProcessAircraft modification • Check if initial aircraft certification basis need to be revised. • Authority team is reduced and includes only relevant specialist ( avionics, powerplant,…). • C of A is « extended » for this modification. • Aircraft Flight Manual may be amended or a supplement may be issued depending on aircraft modification. • Applicant may be either the airframer or an approved design organisation.

10. Airworthiness general Approval ProcessCertification basis and compliance • JAR and FAR airworthiness regulation • JAR/FAR 25 for aircraft > 5.7 t • JAR/FAR 23 for aircraft < 5.7 t • Special condition and Interpretative material • Due to aircraft technology (electrical flight control system, very large transport aircraft,...) • Due to system fitted (Aircraft digital bus, Enhanced Ground Proximity Warning System, predictive windshear,.) • Due to lack of «consolidated» regulation or material (JAA leaflet, AC,..) for this technology/system.

11. Airworthiness general Approval ProcessCertification basis and compliance (Cont’d) • Compliance with requirement material • Means of compliance • Analysis (safety, design robustness,...) • Laboratory test (integration) • Ground test • Flight test • Equipment qualification (environmental, software, minimum operational performance) • Compliance check-list at the end for final airworthiness assessment.

12. Airworthiness general Approval ProcessAircraft modification RNAV example APPLICANT AUTHORITY Aircraft XXX JAR 25 Change 13 RNAV multisensor system installation (GPS/DME). Applicant proposes a Certification plan Cert basis need to be revised due to RNAV system installation? NO Verification of applicable regulation paragraph and interpretative material (AMJ, ACJ,AC). Validation of certification plan Applicant issue documentation, test plan (i.e. ground, flight) and system safety assessment Validation of different document and plan Applicant proceed to relevant test and issue final compliance statement Document and AFM approval. Modification is approved by authority APPROVAL

13. General approval process Operational approval • An airline may operate an aircraft if: • An AOC has been issued by the authority ( Airline Operational Certificate) • Compliance with OPS regulation has been demonstrated (i.e. JAR OPS 1 for transport aircraft category in JAA states) • For certain operation (i.e. CAT III approach, RNP 10……), a dedicated operational approval should be issued by the authority ( for a specific aircraft type, consideration for dedicated crew training and/or maintenance, ...).

14. General approval process AIRWORTHINESS APPROVAL C of A OPERATIONAL APPROVAL AOC AIRCRAFT MAINTENANCE

15. BRNAV ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR

16. Overview of BRNAV certification criteriaCONTENT • Generality • Accuracy • Availability and Integrity • Required functions for BRNAV • Recommended functions for BRNAV • Aircraft Flight Manual (AFM) • Limitation on the use of navigation systems • Operational criteria for use of GPS Stand-alone equipment • BRNAV Certification issues

17. Overview of BRNAV certification criteriaGenerality • Airworthiness criteria defined in a European document (JAA Leaflet 2) • An RNAV system based on navigation sensor. • Sensor may be either VOR/DME, DME/DME, INS/IRS or GPS. • May be a single sensor or multi sensor • BRNAV is sometimes called RNP 5 which may be misleading in certain cases.

18. Overview of BRNAV certification criteriaAccuracy • Track keeping accuracy of 5NM for 95% of the flight time including : • Signal source error (signal transmission error) • Airborne receiver source error • Display system error • Flight technical error 95% 5 NM 5 NM 95%

19. Overview of BRNAV certification criteriaAvailability and Integrity • Total loss of navigation must be improbable (occurrence less than 10-5/per flight hour) • Erroneous displayed information must be improbable (occurrence less than 10-5/ per flight hour) during Enroute operation • Single RNAV system acceptable • Other traditional navigation system installed • System monitored by flight crew

20. Overview of BRNAV certification criteriaAvailability and Integrity : FAR/JAR 1309 Classification

21. Overview of BRNAV certification criteriaRequired functions for BRNAV • Continuous indication of aircraft position relative to track on a navigation display situated in pilot primary field of view • Display of distance and bearing to the active waypoint • Display of ground speed or time to the active waypoint • Storage of waypoints; minimum of 4 • Navigation Data Base is not required • Appropriate failure indication of the RNAV system, including sensors. • Basic BRNAV functions :Low complexity RNAV system with small capacity.

22. Overview of BRNAV certification criteriaRequired functions for BRNAV (example) INDICATOR (i.e CDI) RNAV Control Display Unit (i.e CDU) TO TO TOU Dis 14 NM GS 195 Kts Stored Wpt: AGN; SAU, TAN FLAG AGN TOU SAU 1.25 NM 14 NM 195 Kts TAN

23. Overview of BRNAV certification criteriaRecommended functions for BRNAV • Autopilot and/or Flight director coupling • Display of present position in terms of latitude and longitude • Direct TO function • From present position to a selected waypoint • Indication of navigation accuracy • Quality factor, estimated position error,...

24. Overview of BRNAV certification criteriaRecommended functions for BRNAV • Navigation Data Base • Automatic leg sequencing and associated turn anticipation • Notion of flight plan and transition path • Automatic channel selection of radio navaid • Only for BRNAV systems based on VOR or DME • A BRNAV system with recommended function is a more complex RNAV system which is more in accordance with today’s ATC environment

25. Overview of BRNAV certification criteriaRequired and recommended functions for BRNAV (example) RNAV Control Display Unit (i.e CDU) ADI TO TOUEPE0.15 NM Dis 14 NM GS 195 Kts PPOS N 43 32 59 E 001 35 18 Flight Plan: TOU --> AGN --> SAU --> TAN TO FLAG CDI AGN TOU SAU 1.25 NM 14 NM 195 Kts TAN

26. Overview of BRNAV certification criteriaAircraft Flight Manual (AFM) • AFM includes • Certification basis (i.e Leaflet 2 , AC 20-138) • RNAV system limitation (ex BRNAV limited to 2 hrs in case of pure INS navigation, limitation due to GPS constellation) • RNAV system operating procedure ( An extract of pilot’s guide in order to highlight important operating procedures) • RNAV system abnormal procedure (ex Procedure in case of BRNAV system failure, in case of special navigation messages, ....)

27. Overview of BRNAV certification criteriaLimitation on the use of navigation systems • Inertial Navigation Systems (INS) limited to 2 Hours without automatic radio update function. • GPS should be approved in accordance with TSO C129. • Computed position Integrity should be provided by RAIM (Receiver Autonomous Integrity Monitoring) or equivalent (Alternate Integrity Monitoring including comparison with INS or radio). • In addition to TSO C 129 GPS should include: Pseudorange step detection and health word checking • An equipment compliant with TSO C 129a already includes these two additional functions

28. Overview of BRNAV criteriaOperational criteria for use of GPS Stand-alone equipment • Flight crew should receive appropriate training and be aware of: • Normal procedures • RAIM availability should be confirm in case of degraded GPS constellation (i.e less than 23 satellites) • Nav data base validity (when installed) should be checked • Traditional navigation equipment tuned for cross-check or in case of loss of GPS capability • Abnormal procedures in case of loss of GPS navigation capability • Loss of the integrity function (RAIM unavailable) • Exceedance of the alarm limit (RAIM position Error), revert to an alternate means of navigation

29. Overview of BRNAV certification criteria BRNAV Certification issues • Low integration at cockpit level (stand-alone installation) • RNAV system HMI (CDU complexity, colour, associated crew workload,…) • Autopilot coupling problem which may induce erroneous guidance (compatibility pb between PA and RNAV system) • RNAV system functional problem for other operational use (SID, STAR, approaches): Nav data base problem, flight plan construction, .

30. PRNAV ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR

31. Overview of PRNAV certification criteriaCONTENT • Generality • Accuracy • Availability and Integrity • Required functions for PRNAV • Recommended functions for PRNAV • Sensor limitation • Navigation data base integrity • Operational criteria • PRNAV issues

32. Overview of PRNAV certification criteriaGenerality • Reference material is JAA Leaflet 10 • Lot of discussion during development of this leaflet, more than 500 comments received • Takes into account problems encountered during BRNAV certification process • It accommodates many RNAV system already fitted onboard transport aeroplane category • PRNAV is sometimes called RNP 1 which may be misleading in certain cases.

33. Overview of PRNAV certification criteriaGenerality/ System description • Lateral navigation • Flight plan and navigation data base • PRNAV candidate sensors: DME/DME, VOR/DME, GNSS and INS with automatic radio updating • Display of navigation parameters and desired path • Vertical navigation • No requirement in this leaflet

34. Overview of PRNAV certification criteriaAccuracy • Lateral track keeping accuracy of 1NM for 95% of the flight time including : • Navigation system error (path definition error, position estimation error and display error) • Flight technical error • Accuracy definition of RNP-1 RNAV Path definition error FTE Desired path 95% Defined path TSE 1 NM NSE 1 NM Actual position Estimated position 95%

35. Overview of PRNAV certification criteriaIntegrity • Probability of displaying Hazardously Misleading navigational or positional information simultaneously to both pilot shall be improbable (occurrence less than 10-5 per flight hour) • This is a clear alleviation of existing rule due to: • mitigation means based on current Air traffic Services practises • PAN-OPS and PAN-RAC criteria account for and accommodate this system integrity in current airspace

36. Overview of PRNAV certification criteriaContinuity of Function • Probability of loss of all navigation information should be improbable ( occurrence less than 10-5 per flight hour). • At least one PRNAV system is required if traditional navigation system(VOR,DME,..) are fitted • Air traffic Services may imposed dual PRNAV equipage (i.e. procedure below Minimum obstacle clearance altitude, radar coverage inadequate,…)

37. Overview of PRNAV certification criteriaRequired functions for PRNAV (1/2) • Display indicator with course selector automatically slaved to the RNAV computed path • Navigation data base (including complete PRNAV procedure) • Display of the active navigation sensor type • Display of the active (TO) waypoint • Display of distance and bearing to the active (TO) waypoint • Display of ground speed or time to the active (TO) waypoint • Automatic tuning of VOR and DME navigation aids with capability to inhibit individual navaids(When relevant) • Capability for the « Direct To » function

38. Overview of PRNAV certification criteriaRequired functions for PRNAV (2/2) • Capability to execute transition database procedures (Fly-over and Fly-by turns) • Capability to execute leg transitions and maintain tracks consistent with the following path terminators: • Initial Fix (I.F); Track between two Fixes (T.F); Course to a Fix (C.F), Course from a Fix to an altitude (F.A) and Direct to a Fix (D.F) • Appropriate failure indication of the PRNAV system, including sensors • Display of the active navigation sensor type with a means of determining navigation system performance • Basic PRNAV function : Today's existing FMS lateral navigation function installed on many transport airplane category.

39. Overview of PRNAV certification criteriaRecommended functions for PRNAV • Capability to fly parallel route (Offset function) • Coupling to Flight director and/or automatic pilot • Capability for vertical navigation based upon barometric inputs • Means for automatic runway position update at the start of the take-off (RNAV system using DME/DME updating supported by IRS) • Capability to execute following leg transitions: • Holding pattern (Hx including HM, HA et HF) • Constant radius to a Fix (RF)

40. Overview of PRNAV certification criteriaRequired and recommended functions for PRNAV (example) Multipurpose Control Display Unit (i.e MCDU) ACT RTE1 LEGS 270°3.2 Nm TOU 300-320 306°23 Nm AGN FL 350 227° 46 Nm TBO THEN  ----ROUTE DISCONTINUITY--- LFBO LEGS ETAÞ ADI 270° 306° TO HSI FLAG 180° 00° 90°

41. Overview of PRNAV certification criteriaSensor Limitation • GPS • Same limitation than BRNAV (i.e. step detector plus health word monitoring, ...) • FDE (Fault Detection and Exclusion) function is recommended for availability purposes • INS • PRNAV use in pure INS following a failure of the radio nav update system should be limited in time. • Time duration in pure INS needs to be determined to continue to fulfil PRNAV requirement

42. Overview of PRNAV certification criteriaNavigation Data Base Integrity • Shall comply with ED 76/DO 200A or an equivalent approved procedure. • An approved supplier who has complied with ED 76 (Standards for processing Aeronautical Data) OR • The operator must implement navigation data base integrity checks • Appropriate s/w tool or approved manual procedures • At least for Waypoints below applicable minimum obstacle clearance altitude

43. Overview of PRNAV criteriaOperational criteria • Normal procedures • Pre-flight planning • availability of navigation infrastructure? • Availability of onboard navigation system (including nav data base) • Availability of dual system when AIP specify it • RAIM availability in case of GPS stand-alone system • Departure • Nav data base, a/c position entered, • Active flight plan should be checked (legs, fly-by,…) • user waypoints forbidden for PRNAV operation • Flight progress monitoring (navigational reasonableness, cross check,

44. Overview of PRNAV criteriaOperational criteria (Cont ’d) • Normal procedures • Arrival • Verification that correct terminal procedure is loaded and flight plan construction correct • Creation of new waypoints by manual entry is forbidden • Flight progress should be monitored • Notion of route modification in terminal area (radar heading or Dir To clearance) • Any published altitude and speed constraints must be observed • Contingency procedures • Failure of the RNAV system components, multiple system failures • Loss of required navigation capability • Loss of PRNAV capability

45. Overview of PRNAV certification criteriaPRNAV Issues • PRNAV is a transition towards RNP-1-RNAV • PRNAV may be requested by some states in the near future • Problem of navigation data base integrity should be addressed • ATS provider/Designer should take into account alleviation of integrity criteria at aircraft level • However many FMS installed on transport aircraft category fulfil airworthiness criteria defined in JAA Leaflet 10

46. BRNAV/PRNAVEXAMPLE ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR

47. Aircraft and BRNAV

48. Aircraft and PRNAVPresently there is no aircraft officialy PRNAV approved

49. GENERALITY ON RNP ARAB INSTRUMENT PROCEDURE DESIGN SEMINAR

50. WHAT IS RNPDefinition/Generality • RNP as defined in ICAO doc 9613 : • A statement of the navigation performance accuracy necessary for operation within a defined airspace. • RNP as defined in ICAO doc 9650 : • A statement of the navigation performance accuracy, integrity, continuity and availability necessary for operation within a defined airspace. • RNP from an airborne point of view is defined by the RNP-(x)-RNAV concept described in document ED 75() or DO 236(). These system fully support definition of ICAO doc 9650 (accuracy, integrity and continuity).