September 2002-MoroccoARAB INSTRUMENT PROCEDURE DESIGN SEMINAR 1 RNAV AIRBORNE SYSTEM AIRWORTHINESS REGULATION AND CERTIFICATION ISSUES B. RABILLER / French DGAC SFACT/ Aircraft Certification Office

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

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

INTRODUCTION RNAV SYSTEM FOR GENERAL AVIATION (EXAMPLE) HSI (Horizontal Situation Indicator) GPS Receiver Aircraft interfaces (Power, Altitude,..). GPS antenna NAV WPT GNSS MSGAPPR External annunciator

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

September 2002-MoroccoARAB INSTRUMENT PROCEDURE DESIGN SEMINAR 6 AIRCRAFT CERTIFICATION PROCESS

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

Airworthiness general Approval Process Type 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!

Airworthiness general Approval Process Aircraft 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.

Airworthiness general Approval Process Certification 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.

Airworthiness general Approval Process Certification basis and compliance (Cont’d) u 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.

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

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,...).

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

September 2002-MoroccoARAB INSTRUMENT PROCEDURE DESIGN SEMINAR 15 BRNAV

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

Overview of BRNAV certification criteria Generality u Airworthiness criteria defined in a European document (JAA Leaflet 2) u 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 ë BRNAV is sometimes called RNP 5 which may be misleading in certain cases.

Overview of BRNAV certification criteria Accuracy u 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 5 NM 95%

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

Overview of BRNAV certification criteria Availability and Integrity : FAR/JAR 1309 Classification

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

Overview of BRNAV certification criteria Required functions for BRNAV (example) TO TO TOU Dis14 NMGS195 Kts Stored Wpt:AGN; SAU, TAN FLAG TOU 1.25 NM 14 NM SAU AGN TAN 195 Kts INDICATOR (i.e CDI)RNAV Control Display Unit (i.e CDU)

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

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

Overview of BRNAV certification criteria Required and recommended functions for BRNAV (example) TO TO TOUEPE0.15 NM Dis14 NMGS195 Kts PPOSN E Flight Plan: TOU -->AGN --> SAU --> TAN FLAG TOU 1.25 NM 14 NM SAU AGN TAN 195 Kts RNAV Control Display Unit (i.e CDU) ADI CDI

Overview of BRNAV certification criteria Aircraft Flight Manual (AFM) u AFM includes – Certification basis (i.e Leaflet 2, AC ) – 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,....)

Overview of BRNAV certification criteria Limitation on the use of navigation systems u Inertial Navigation Systems (INS) limited to 2 Hours without automatic radio update function. u 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

Overview of BRNAV criteria Operational criteria for use of GPS Stand- alone equipment u Flight crew should receive appropriate training and be aware of: ì 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 ì 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

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

September 2002-MoroccoARAB INSTRUMENT PROCEDURE DESIGN SEMINAR 30 PRNAV

Overview of PRNAV certification criteria CONTENT u Generality u Accuracy u Availability and Integrity u Required functions for PRNAV u Recommended functions for PRNAV u Sensor limitation u Navigation data base integrity u Operational criteria u PRNAV issues

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

Overview of PRNAV certification criteria Generality/ System description u 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 u Vertical navigation – No requirement in this leaflet

Overview of PRNAV certification criteria Accuracy u 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 ê Accuracy definition of RNP-1 RNAV 1 NM 95% FTE NSE TSE Path definition error Desired path Defined path Estimated position Actual position

Overview of PRNAV certification criteria Integrity u Probability of displaying Hazardously Misleading navigational or positional information simultaneously to both pilot shall be improbable (occurrence less than 10-5 per flight hour) u 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

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

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

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

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

Overview of PRNAV certification criteria Required and recommended functions for PRNAV (example) TO ACT RTE1LEGS 270°3.2 Nm TOU °23 Nm AGNFL °46 Nm TBO THEN  ----ROUTE DISCONTINUITY--- LFBO LEGS ETA  FLAG ADI HSI 90° 180° 270° 00° 306° Multipurpose Control Display Unit (i.e MCDU)

Overview of PRNAV certification criteria Sensor Limitation u GPS – Same limitation than BRNAV (i.e. step detector plus health word monitoring,...) – FDE (Fault Detection and Exclusion) function is recommended for availability purposes u 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

Overview of PRNAV certification criteria Navigation Data Base Integrity u Shall comply with ED 76/DO 200A or an equivalent approved procedure. ñ An approved supplier who has complied with ED 76 (Standards for processing Aeronautical Data) OR ñ 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

Overview of PRNAV criteria Operational criteria u 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,

Overview of PRNAV criteria Operational criteria (Cont ’d) u 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 u Contingency procedures – Failure of the RNAV system components, multiple system failures – Loss of required navigation capability – Loss of PRNAV capability

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

September 2002-MoroccoARAB INSTRUMENT PROCEDURE DESIGN SEMINAR 46 BRNAV/PRNAV EXAMPLE

Aircraft and BRNAV

Aircraft and PRNAV Presently there is no aircraft officialy PRNAV approved

September 2002-MoroccoARAB INSTRUMENT PROCEDURE DESIGN SEMINAR 49 GENERALITY ON RNP

WHAT IS RNP Definition/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).

RNP RNP-RNAV Generality  RNP-(x)-RNAV airborne system:  RNP Accuracy is defined as the total system error (x) 95% of the flying time. (x) is the RNP value.  Containment integrity: Probability that the total system error exceeds the specified containment limit without annunciation. Shall be less than 10-5 per flight hour (99.999%). Containment limit is twice the RNP value (x).  Containment continuity : Probability of annunciated loss of RNP RNAV capability shall be less than 10-4 per flight hour (99.99%).

RNP RNP-RNAV Generality RNP RNP-RNAV Generality Accuracy Integrity % 95% % Desired route 2 x RNP 1 x RNP