TITLE PAGE CAGE CODE CONTRACT NO. IR&D OTHER. PREPARED ON PC/Word for Windows 7.0 FILED UNDER

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1 TITLE PAGE CAGE CODE 8205 THIS DOCUMENT IS: CONTROLLED BY B-E ALL REVISIONS TO THIS DOCUMENT SHALL BE APPROVED BY THE ABOVE ORGANIZATION PRIOR TO RELEASE. PREPARED UNDER - - x CONTRACT NO. IR&D OTHER PREPARED ON PC/Word for Windows 7.0 FILED UNDER DOCUMENT NO. D MODEL /400/ /700/800 TITLE RNP Capability of FMC Equipped 737, Generation 2 ORIGINAL RELEASE DATE ISSUE NO. TO DATE x THE INFORMATION CONTAINED HEREIN IS NOT PROPRIETARY. THE INFORMATION CONTAINED HEREIN IS PROPRIETARY TO THE BOEING COMPANY AND SHALL NOT BE - REPRODUCED OR DISCLOSED IN WHOLE OR IN PART OR USED FOR ANY DESIGN OR MANUFACTURE EXCEPT WHEN SUCH USER POSSESSES DIRECT, WRITTEN AUTHORIZATION FROM THE BOEING COMPANY. ANY ADDITIONAL LIMITATIONS IMPOSED ON THIS DOCUMENT WILL BE FOUND ON A SEPARATE LIMITATIONS PAGE. SIGNATURE ORGN DATE PREPARED BY CHECKED BY APPROVED BY H. R. Shomber D. L. Willis R. S. Leslie B-E B-E B-E Revision - NEW D Page of 36

2 ABSTRACT This document states FMCS navigation system capabilities for a /400/500/600/700/800 upgraded with addition of GPS. It is intended to be used by the FMC Group, the Customer Airlines and the Operational Approval Regulatory Authorities to document the navigation capabilities introduced with the U0 FMC in order to facilitate the Customer Airlines in receiving operational approvals. This document describes assumed operating environment, the interface of the FMC navigation function to the Flight Crew, the specific navigation capabilities of the FMCS equipment, and potential application of the FMCS navigation system. KEY WORDS Computer FMC GPS Navigation RNP Satellite Revision - D Page 2

3 TABLE OF CONTENTS TITLE PAGE... ABSTRACT...2 KEY WORDS...2 TABLE OF CONTENTS...3 LIST OF FIGURES...4 ACRONYMS AND ABBREVIATIONS...5. Introduction...6. Purpose Scope Actual Navigation Performance (ANP) ANP When GPS Updating ANP When Radio Updating and IRS Only Required Navigation Performance (RNP) RNP - Accuracy RNP - Integrity RNP - Availability of Navigation Signals RNP - Availability of Navigation Equipment Flight Crew Interface Updates for RNP and GPS Position Reference Page 2/ Position Shift 2/ Navigation Status Page / Navigation Options Page 2/ Route Legs Page CDU Scratch Pad Messages GPS Failure Indications Navigation System Capability Definitions Primary Means Navigation System Supplementary Means Navigation System Primary Means RNP Example Navigation Capability of the FMCS GPS/FMC/IRS RNP Availability Preliminary Method for Predicting GPS/IRS/FMC RNP Availability FMC ANP Capability Flight Technical Error (FTE) FMCS AFM Rationale for AFM Words Proposed FMCS MMEL Possible Application of RNP Enroute/Terminal Route Separation Terminal/Approach Obstacle Clearance RNP Approach Equivalent to NDB/(DME), VOR(/DME), RNAV or GPS Approaches Proposed Operational Approval Criteria and Method...36 Revision - D Page 3

4 LIST OF FIGURES FIGURE PAGE 3.- Default RNP POS REF 2/3 Page POS SHIFT 3/3 Page (Dual GPS updating) NAV STATUS /2 Page NAV OPTIONS 2/2 Page RTE LEGS Page FMCS/GPS/IRS World-Wide Availability of Selected RNP FMCS/GPS/IRS Navigation Performance Capability Versus Selected RNP FMC ANP Capability Flight Technical Error Minimum RNP With GPS Updating - Enroute & Terminal Operations Minimum RNP Without GPS Updating- Enroute & Terminal Operations Minimum RNP With GPS Updating - Approach Operations Minimum RNP Without GPS Updating- Approach Operation Approach Exposure Time Equivalent RNP Values for Approaches...35 Revision - D Page 4

5 ACRONYMS AND ABBREVIATIONS A/P AFM ANP ANP CT ATC ATS CDU CRT DME EHSI F/D FANS FAR FMC FMCS FTE FTE CT G/S GIB GPS GPSSU HIL ICAO IFR ILS IRS IRU LNAV LOC LOC-BC MLS MMEL MOPS NDB NM NOTAM RAIM RDMI RNAV RNP RTE SDF TOGA VNAV VOR WAAS Autopilot Aircraft Flight Manual Actual Navigation Performance Actual Navigation Performance Containment Radius Air Traffic Control Air Traffic Services Control Display Unit Containment Radius Threshold Distance Measuring Equipment Electronic Horizontal Situation Indicator Flight Director Future Air Navigation System Federal Aviation Regulations Flight Management Computer Flight Management Computer System Flight Technical Error Flight Technical Error Containment Radius ILS Glideslope GPS Integrity Broadcast Global Positioning System Global Positioning System Sensor Unit Horizontal Integrity Limit International Civil Aviation Organization Instrument Flight Rules Instrument Landing System Inertial Reference System Inertial Reference Unit Lateral Navigation Localizer Localizer Back Course Microwave Landing System Master Minimum Equipment List Minimum Operational Performance Standards Navigation Database Nautical Mile Notice to Airman Receiver Autonomous Integrity Monitor Radio Distance Magnetic Indicator Area Navigation Required Navigation Performance Route Simplified Directional Facility Takeoff/Go-Around Vertical Navigation Very High Frequency Omnidirectional Range Wide-Area Augmentation System Revision - D Page 5

6 . Introduction. Purpose The purpose of this document is to provide an overview of the navigation capabilities of a /400/500/600/700/800 upgraded with addition of GPS and functionality first introduced in the U0 FMCS. The navigation capabilities described have been FAA Part 25 certified in November 997. This document is a working paper to provide the regulatory authorities with the data they require to provide the airlines Part 2 flight operations approval to fly enroute, terminal and approach flight operations using RNP, in a timely fashion following the certification of the FMCS. This document is an update of D , "RNP Capability of FMCS Equipped 737, Generation ". The significant differences are the revised primary means RNP values, nav database specified RNP values, AFM changes to reflect approach operations, and equivalent RNP values for NDB approaches. The RNP environment and the associated assumptions are the same..2 Scope This document provides an overview of the RNP and GPS navigation capabilities provided by the FMCS. This document does not provide an overview of all the existing navigation capabilities prior to the U0 FMCS. Refer to the following documents for discussions applicable to the indicated models: Model Document Number D240U26 757/767 D926T D243W08-7 Revision - D Page 6

7 2. Actual Navigation Performance (ANP) Actual Navigation Performance (ANP) is the actual computed navigation system accuracy with associated integrity for the current FMC position. It is expressed in terms of nautical miles and represents a radius of a circle centered around the computed FMC position where the probability of the aircraft being inside the circle is 95%. The computed accuracy, ANP, is displayed to the crew as ACTUAL (navigation performance) and annunciation is provided if ANP (ACTUAL) exceeds the selected RNP. The FMC computation of ANP does not account for the following error sources: ) Software errors in the FMC or Sensor. 2) Flight Technical Error. (This includes position errors induced by guidance systems ability to follow a track in various wind conditions or the ability of the pilot to manually keep the aircraft on track using LNAV (flight director) or the electronic map. The integrated cockpit design of the /400/500/600/700/800 with the FMCS provides indications of FTE to the crew via the following: electronic map display; LNAV engage, disengage; autopilot/flight director engage, disengage, and fail status.) 3) Errors in time source used when reporting the position. 4) Position errors in the navigation database data or resulting from incorrect manual waypoint entry. 5) Differences in local datum other than WGS ANP When GPS Updating The FMC computed accuracy when GPS updating considers the following error sources: ) Position errors induced by the satellite constellation (Reflected in HIL). 2) Position errors induced in the navigation sensors on the airplane (GPS data latencies). The GPS position integrity in the FMC is provided by GPS Receiver Autonomous Integrity Monitor (RAIM). RAIM has a containment protection level probability of E-7 per flight hour by definition. RAIM computes an actual containment radius (horizontal integrity limit, HIL) that is a function of the actual detected error in the GPS pseudoranges. The FMC uses GPS, deweighted by the HIL, as part of the multi-sensor navigation. As such, the displayed ANP is predicated upon the worst undetected satellite failure, assuring the error contribution of GPS is appropriately considered. In addition, the GPS outputs a horizontal figure of merit (HFOM), which represents the 95% containment, assuming no undetected failures. Two cases of GPS operation are analyzed, normal operation and satellite failure. The FMC updating option "GPS with Integrity Limit" is assumed for this discussion. The FMC updating option "GPS without Integrity Limit" has ANP characterstics defined in section 2.2. Revision - D Page 7

8 For normal operation, the navigation position is assumed to have a Rayleigh probability distribution. The displayed ANP is 0.56*HIL, due to the scaling of HIL used by the FMC. In addition, the ratio of r acc (HFOM from the GPSSU) to HIL has an upper bound of 0.4. Consequently, : r acc = (0.4/0.56)*ANP r acc = 0.7*ANP Where r acc is the 95% containment of the navigation position The second case for the FMC-GPS-IRS configuration is a satellite ramp failure, followed by loss of valid GPS data when the satellite failure is detected. Simulation of the FMC navigation algorithm and covariance analysis, indicate the navigation position error is bounded by.8*anp. The r acc value and the position bound on the error are used in section 0 to derive the minimum RNP values for the AFM. 2.2 ANP When Radio Updating and IRS Only The FMC computed position accuracy when radio updating, extrapolating radio updates, or IRS only considers the following error sources: ) Position errors induced by the navigation aids. (Incorrect survey locations of the navaid in the NDB, ground based navaid signal in space errors, update navaids DME/DME geometry errors) 2) Position errors as the result of IRS drift in the IRS only mode. 3) Position errors induced in the navigation sensors on the airplane. (DME, VOR, and IRS position errors and data latencies) Two operational cases are analyzed, normal operation and undetected failure operation. For the normal operation case, the calculation of ANP (ACTUAL) is used. The displayed ANP (ACTUAL) is computed from the largest of the North or East position standard deviation. These standard deviations are nearly equal when GPS updating, but are significantly different when radio updating, since they are dependent upon the geometry of the navaids used for position updating. The ratio, smallest to largest, averages 0.90 for enroute and terminal environments and 0.80 for approach environments. The different ratio is due to the more severe navaid geometry encountered in the approach environment. The 95% containment for a displayed ANP (ACTUAL) can be computed from the circular approximation to the elliptical distribution. The displayed ANP is calculated using the largest position standard deviation (North or East), as the basis for a Rayleigh distribution. ANP = 2.45*S max where S max = largest of North or East position standard deviation The actual 95% containment circle can be approximated, conservatively, by r acc = 2.45*(0.5*(S north + S east )) where S north = North position standard deviation S east = East position standard deviation Revision - D Page 8

9 Or equivalently, the 95% containment radius can be computed from the displayed ANP as: r acc = 0.95*ANP r acc = 0.90*ANP (Enroute Operations) (Approach Operations) The second case is an undetected navigation data error or sensor failure. The navigation reasonableness checks will reject a radio update, when the difference between the FMC and radio position exceeds.02*anp. Consequently, the position error introduced by radio update can be bounded by.02*anp. The r acc value and the position bound on the error are used in section 0 to derive the minimum RNP values for the AFM. Revision - D Page 9

10 3. Required Navigation Performance (RNP) For the FMCS, Required Navigation Performance (RNP) is defined as follows: "Required Navigation Performance (RNP) is a statement of the navigation performance necessary for operation within a defined airspace" (Adapted from accepted ICAO definition of RNP) RNP specifies an accuracy, integrity, availability of navigation signals and availability of navigation equipment requirements for a particular area, airspace, route, procedure, or operation. For the FMCS, the initial implementation of RNP focuses on horizontal applications. The Control Display Unit (CDU) displays ANP, RNP (default, nav database specified, or manually-entered values) and associated CDU scratch pad messages. The "IRS NAV ONLY" CDU message, in conjunction with the amber FMC light on the pilots' instrument panels, is issued whenever the ANP exceeds the default RNP. When manual RNP capability is not disabled (airline option) or nav database specified RNP value are used, the "UNABLE REQD NAV PERF-RNP" CDU message, in conjunction with the amber FMC light on the pilots' instrument panels, is provided to the flight crew to indicate ANP exceeding manually entered or Nav Database specified RNP. When operating in an approach navigation phase with a manually entered or Nav Database specified RNP, the UNABLE REQD NAV PERF-RNP is also displayed on the EHSI MAP. Oceanic, Enroute, Terminal, and Approach navigation phases of flight are implemented, and used to select default RNP values and times to alarm for issuing the CDU messages. The initial certification values for these parameters are based on the existing operational requirements for existing airspace. The default values for the FMCS are defined in Figure 3.-. "IRS NAV ONLY" Message (Default RNP) "UNABLE REQD NAV PERF-RNP" Msg (Manual RNP) Time To Issue Message (seconds) Phase of Flight Default RNP (NM) Enroute Oceanic 2.0 CDU & FMC Light CDU & FMC Light 80 Enroute Domestic 2.0 CDU & FMC Light CDU & FMC Light 80 Terminal.0 CDU & FMC Light CDU & FMC Light 60 Approach 0.5 CDU & FMC Light CDU, EHSI Map & FMC Light Figure 3.- Default RNP Definition for each of the above flight phases are given below: 0 Oceanic: Enroute: Terminal: Approach: Radio updating is not viable due to either very limited navaid coverage or no navaid coverage. Aircraft is above 5,000 feet and radio updating is viable. Aircraft is below 5,000 feet and not in Approach environment The aircraft has passed within 2nm of the first waypoint on the active approach or approach transition or the aircraft descends below 2,000 feet above destination airport elevation. Approach flight phase is exited when the missed approach hold fix is reached, or the aircraft climbs above 3000ft above the airport elevation when no missed approach has been specified. Revision - D Page 0

11 3. RNP - Accuracy Accuracy is a 95% horizontal position certainty radius around the computed position. It indicates the normal operating error characteristics of a navigation system. The RNP accuracy considers the following error sources: ) Position errors induced by the navigation aids or GPS satellite constellation. 2) Position errors induced by the navigation sensors on the airplane. 3) Position errors induced by the navigation system (FMC). The RNP accuracy does not consider the following error sources: ) Software errors in the FMC or Sensor. 2) Flight Technical Error. 3) Errors in time source used when reporting the position. 4) Position errors in the navigation database data or resulting from incorrect manual waypoint entry. 5) Differences in local datum other than WGS RNP - Integrity Integrity is represented by a horizontal containment radius around the computed FMC position, and a containment protection level probability that the actual position is outside the containment radius. If the actual position falls outside the containment radius, this is an unannunciated exceedance of RNP. The RNP integrity considers the following error sources: ) Position errors induced by the navigation aids or GPS satellite constellation. 2) Position errors induced by the navigation sensors on the airplane. 3) Position errors induced by the navigation system (FMC). 4) Flight Technical Error. The RNP integrity does not consider the following error sources: ) Software errors in the FMC or Sensor. 2) Errors in time source used when reporting the position. 3) Position errors in the navigation database data or resulting from incorrect manual waypoint entry. 4) Differences in local datum other than WGS-84. For a given RNP, the containment radius threshold requirement will be equal to RNP times two. This containment radius will be used in providing sufficient route separation and obstacle clearance. For a given RNP, the containment protection level probability will vary depending on the operational requirement. For enroute and terminal area operations route separation, the containment protection level probability requirement is E-5 per flight hour. For terminal and approach procedures obstacle clearance, the containment protection level probability requirement is E-7 per procedure (i.e. approximately E-6 per flight hour assuming approximately a 6 minute exposure for the approach). RNP integrity accounts for Flight Technical Error by the FMC position integrity containment protection level probability for GPS and non-gps updating being well within the stated requirements for enroute, terminal and approach area operations. This allows some of the RNP containment threshold to be allocated for Flight Technical Error. Therefore knowing the Flight Technical Error characteristics for various modes of flight, a minimum RNP can be computed and demonstrated for each mode of flight and documented in the Airplane Flight Manual (AFM). See sections 0. and 0.2 for example calculations. Revision - D Page

12 3.3 RNP - Availability of Navigation Signals Availability of navigation signals is the probability that the required navigation signals external to the aircraft will be present during the planned flight operation to provide the required level of accuracy and integrity for the selected RNP. Availability of navigation signals for GPS updating is based upon the number of satellites in the GPS constellation and their ability to provide the required GPS signals to meet the required accuracy and integrity for the selected RNP. Availability of navigation signals for radio updating is based on navaid coverage for the region of operation and their ability to provide the required radio signals to meet the required accuracy and integrity for the selected RNP. 3.4 RNP - Availability of Navigation Equipment Availability of navigation equipment is specified by the probability that the required navigation equipment on the airplane will be operational during the planned flight operation to perform the required navigation. Availability of navigation equipment is achieved by providing redundancy of the navigation systems on the airplane, while considering the reliability of each component used to perform each navigation operation. Availability of navigation equipment is measured by performing an analysis of the airplane architecture redundancy and the failure rates of equipment required for the various navigation operations. Revision - D Page 2

13 4. Flight Crew Interface Updates for RNP and GPS Functional crew interface requirements for the GPS and RNP functions include CDU pages for display of GPS and RNP information and to provide certain control features, and include the CDU scratch pad which provides related annunciation. This also includes warning lights (pilots' instrument panels, IRS Mode Select Unit, Master Caution) for indications of specific failures. 4. Position Reference Page 2/3 L 3 2L 5 3L 7 4L P O S R E F 2 / 3 F M C P O S G S N W K T R I R S L N W K T 2R I R S R N W K T 3R G P S L N W R G P S R 5L N W R R A D I O 6L 3 N W R Figure 4.- POS REF 2/3 Page L FMC POS Displays Lat/Lon of the position used for guidance, as computed by the FMC. Can be line selected to scratchpad for movement to 4R on POS INIT page /3. Data field is blank if FMC position is invalid. 2L-3L IRS-L/IRS-R POS Displays Lat/Lon as computed by indicated IRS. Can be line selected to scratchpad for movement to 4R on POS INIT page /3. Data field is blank if corresponding IRS position is invalid. 4L-5L GPS-L/GPS-R POS Displays Lat/Lon as computed by indicated GPS. Can be line selected to scratchpad for movement to 4R on POS INIT page /3. Data field is blank if corresponding GPS position is invalid. Header and data fields are blank when GPS is disabled. 6L RADIO POS Displays Lat/Lon of radio position as computed by the FMC. Can be line selected to scratchpad. Data field is blank on the ground or when radio position is invalid. Revision - D Page 3

14 4.2 Position Shift 2/3 Pos Shift page (Dual GPS updating). L 3 2L 5 3L 7 4L P O S S H I F T 3 / 3 F M C - L F M C - R < / 0. 0 N M / 0. N M > R G P S - L G P S ( 2 ) G P S - R 2R < / 0. N M / 0. 0 N M > I R S - L I R S ( 2 ) I R S - R 3R < / 0. N M 0 / 0 N M > R N P / A C T U A L R A D I O 4R / 0. 5 N M / 0. 4 N M > L 5R N A V S T A T U S > L 3 < I N D E X 6R Figure 4.2- POS SHIFT 3/3 Page (Dual GPS updating) L,R FMC-L/FMC-R Current FMC-L or FMC-R position relative to the FMC position displayed in POS REF L. Selection and execution allows pilot override (one-shot) of FMC navigation to selected position. 2L,2R GPS-L/GPS-R Current GPS-L or GPS-R position relative to the FMC position displayed in POS REF L. Selection and execution allows pilot override (one-shot) of FMC navigation to selected position. 3L,3R IRS-L/IRS-R Current IRS-L or IRS-R position relative to the FMC position displayed in POS REF L. Selection and execution allows pilot override (one-shot) of FMC navigation to selected position. 4L RNP/ACTUAL Provides for display and manual selection of RNP (required navigation performance), along with display of ANP (actual navigation performance). 2C,3C GPS(x) or IRS(x) Displays currently selected GPS or IRS, where x = L,R, 2 or blank. Note: 2 is only used in dual systems and indicates both GPSs or IRSs are used in the FMC position calculation. 4R RADIO Current radio position relative to the FMC position displayed in POS REF L. Selection and execution allows pilot override (one-shot) of FMC navigation to selected position. Revision - D Page 4

15 4.3 Navigation Status Page /2 With Dual GPS, Agility DME-DME and LOC-DME Updating L 3 2L N A V S T A T U S / 2 V O R - L I L S - R R I B F I D M E - L D M E - R S E A I B F I R E P H L 7 3R L 9 4R 5L G P S ( 2 ) I R S ( 2 ) 5R 6L 3 < I N D E X P O S S H I F T > 6R Figure 4.3- NAV STATUS /2 Page L,R VOR/ILS IDENTIFIERS and FREQUENCIES Displays the VOR and ILS identifier and frequency that corresponds to the VHF NAV control panel frequency. Blank during agility DME operation. Inverse video indicates the data is being used in the FMC navigation. 2L,2R through 4L-4R DME IDENTIFIERS and FREQUENCIES Displays the DME identifiers and frequencies that are being tuned. Inverse video indicates the data is being used in the FMC navigation. 5L,5R GPS(x) and IRS(x) Displays currently selected GPS and IRS, where x = L,R, 2 or blank. Note: 2 is only used in dual systems and indicates both GPSs or IRSs are used in the FMC position calculation. Revision - D Page 5

16 4.4 Navigation Options Page 2/2 L 3 2L 5 3L 7 4L N A V O P T I O N S 2 / 2 D M E I N H I B I T R V O R I N H I B I T R D M E U P D A T E G P S U P D A T E < O N / O F F O N / O F F > 3R V O R U P D A T E < O N / O F F 4R L 5R 6L 3 < I N D E X 6R Figure 4.4- NAV OPTIONS 2/2 Page L,R DME INHIBIT Up to two navaids can be entered to inhibit the use of the selected navaid for navigation updating. 2L,2R VOR INHIBIT Up to two navaids can be entered to inhibit the use of the selected navaid for navigation updating. 3L DME UPDATE ON/OFF Provides the means for selecting DME Update Mode. Line selection toggles the update mode between "ON" / "OFF". 4L VOR UPDATE ON/OFF Provides the means for selecting VOR Update Mode. Line selection toggles the update mode between "ON" / "OFF". 3R GPS UPDATE ON/OFF Provides the means for selecting GPS Update Mode. Line selection toggles the update mode between "ON" / "OFF". Revision - D Page 6

17 4.5 Route Legs Page Added RNP/ACTUAL to existing legs page for ease of reference L A C T R T E L E G S / N M E N O / F L R L R 3L 7 3R 4L 9 4R 5L 5R R N P / A C T U A L E X T E N D E D 6L 6R / 0. 2 N M D A T A > Figure 4.5- RTE LEGS Page 6L RNP/ACTUAL Provides for display and manual selection of RNP (required navigation performance), along with display of ANP (actual navigation performance). Note: The manually selected RNP is displayed in large font. 4.6 CDU Scratch Pad Messages All of the following messages, with the exception of VERIFY RNP VALUE message, when issued on the CDU scratch pad, will be accompanied by an amber FMC light on both pilot instrument panels, which will be extinguished when the message reset logic has been satisfied. IRS NAV ONLY The ANP (ACTUAL) value is larger than the default RNP. Reset: CDU "CLR" key or set condition no longer true UNABLE REQD NAV PERF-RNP The ANP (ACTUAL) value is larger than the manually entered or Nav Database specified RNP. When on approach, this message is also displayed in amber text across the EHSI map. Reset: CDU "CLR" key or set condition no longer true. Only the CDU message will clear in this case. Deleting the manually entered RNP will delete the amber text from the EHSI. Revision - D Page 7

18 VERIFY POSITION The difference between GPS (if enabled) or computed radio position and FMC position, or the difference between left and right FMC positions exceeds the RNP. Reset: CDU "CLR" key or set condition no longer true VERIFY RNP With Manual RNP entry enabled, the default or Nav Database specified RNP changes and the manually entered RNP exceeds the new default or Nav Database specified RNP value, or a GPS approach is initiated with a default RNP value. Reset: CDU "CLR" key or set condition no longer true VERIFY RNP VALUE With Manual RNP entry enabled, a manual RNP entry exceeds either the default or Nav Database specified RNP value or is less than the ANP value (ACTUAL). Reset: CDU "CLR" key or set condition no longer true NAV INVALID TUNE xxxx Data from an RNAV or VOR approach procedure specified navaid is not available. Reset: CDU "CLR" key or set condition no longer true To avoid nuisance messages, all of the above messages are inhibited when one of the following is true:. VOR/LOC mode is engaged (another system is controlling the lateral path). 2. VOR/ILS mode is selected on one EHSI and both radios are tuned to the procedure navaid (Raw radio data displayed for position cross-check). 4.7 GPS Failure Indications GPS failures are indicated to the flight crew via the "GPS" light in the IRS Mode Select Unit, the IRS Master Caution light and the Captain's and First Officer's Master Caution lights. Failure of both GPSSUs lights all of these lights. Failure of just one GPSSU is indicated only during the recall test (part of preflight and landing checklists). Revision - D Page 8

19 5. Navigation System Capability Definitions The definition of Primary and Supplementary navigation systems in terms of RNP are provided. 5. Primary Means Navigation System Primary Means - An integrated navigation system where greater than % of the time, ANP is less than RNP. This includes loss of external navigation system signals (i.e. not enough valid GPS satellites in view, or insufficient navaid coverage), and airplane navigation equipment availability (i.e. the failure rate of the navigation system to perform this function must be less than E-5 per flight hour). Failure of a "Primary Means" system may result in, or require reversion to a "non-normal" means of navigation or an alternate RNP. 5.2 Supplementary Means Navigation System Supplementary Means - An integrated navigation system where less than % of the time, ANP is less than RNP. Failure of a "Supplementary Means" system may result in, or require reversion to, another RNP or alternate "normal" means of navigation for that area, airspace, route, procedure, or operation. 5.3 Primary Means RNP Example The following is an example of what is defined by a Primary Means RNP.0. Primary Means RNP.0 defines an accuracy requirement of.0 NM, a containment radius threshold requirement of 2.0 NM, an availability of navigation signals requirement to greater than %, and an availability of navigation equipment requirement of greater than E-5 per flight hour for loss of function. The containment protection level probability requirement will be a function of the type of flight operation. For enroute and terminal area operations route separation, the containment protection level probability requirement is E-5 per flight hour. For terminal area and approach procedures obstacle clearance, the containment protection level probability requirement is E-7 per procedure. Revision - D Page 9

20 6. Navigation Capability of the FMCS The navigation capability of the airplane is defined by the navigation signals available at the current airplane location and the operational sensor on the airplane. The following sections define the airplane's navigation capabilities in terms of GPS satellite signal available to fly a selected RNP and the range and or typical values of ANP based on the position update mode. 6. GPS/FMC/IRS RNP Availability Figure 6.- is a summary of FMC/GPS/IRS RNP availability. The data is based on the following GPSSU and satellite configuration assumptions which apply to the FMCS system: ) No Baro-Aiding (RAIM augmentation), no local area or wide area differential, or GIB (Global Integrity Broadcast) in the GPSSU. 2) A 2.0 degree mask angle in the GPSSU. 3) Dual FMC installation. Number of FMCS/GPS/IRS World-Wide Availability of Selected RNP Satellites In GPS Constellation RNP 2.0 RNP 4.0 RNP 2.0 RNP.0 RNP 0.5 RNP 0.3 RNP or more. >99.999% >99.999% >99.999% >99.999% >99.99% >99.98% >98.84% 23 >99.999% >99.999% >99.999% >99.98% >99.86% >99.46% >94.68% 22 >99.999% >99.999% >99.97% >99.78% >99.7% >97.82% >88.50% 2 >99.999% >99.98% >99.80% >99.5% >97.54% >94.59% >80.59% Note: RNP 4.0,0.3, 0.5 require manual pilot selection. Figure 6.- FMCS/GPS/IRS World-Wide Availability of Selected RNP Revision - D Page 20

21 Based on the above results, the FMCS is capable of providing the levels of navigation with GPS as defined in Figure 6.-2: Number of Satellites In GPS Constellation FMCS/GPS/IRS Navigation Performance Capability Versus Selected RNP RNP 2.0 RNP 4.0 RNP 2.0 RNP.0 RNP 0.5 RNP 0.3 RNP or more PRIM PRIM PRIM PRIM SUPP*+ SUPP+ 23 PRIM PRIM PRIM SUPP*+ SUPP*+ SUPP+ 22 PRIM PRIM SUPP*+ SUPP*+ SUPP*+ SUPP+ 2 PRIM SUPP*+ SUPP*+ SUPP*+ SUPP*+ SUPP+ Note: RNP 4.0, 0.3, 0.5 require manual pilot selection. Figure 6.-2 FMCS/GPS/IRS Navigation Performance Capability Versus Selected RNP Key: PRIM Primary means of navigation per the definition in section 5.. SUPP Supplementary means of navigation per the definition in section 5.2. * Indicates that the selected RNP is available as a primary means of navigation if in a region of DME/DME navigation radio coverage. + Indicates that the selected RNP may be available as a primary means of navigation if a prediction has been performed that shows there will be sufficient GPS accuracy and integrity during the time and place where the RNP flight operation is to be flown. 6.2 Preliminary Method for Predicting GPS/IRS/FMC RNP Availability The airlines may use off the shelf GPS prediction programs, specific to their GPSSU, to predict that the availability of GPS accuracy and RAIM provided integrity is available during the time and place where the RNP flight operation is to be flown. The off the shelf prediction program should be able to identify specific satellites that have been identified by the NOTAM service as not operational and should consider them in the predictions. This prediction may be done at the time of dispatch, and may also be available just prior to performing a specific flight operation via voice or data communications. As other forms of GPS augmentation are developed (GIB, WAAS), the requirement for confirming availability of integrity will be met through the augmentation systems, and a route specific prediction will not be required for dispatch. Revision - D Page 2

22 6.3 FMC ANP Capability Figure 6.3- contains the ANP capabilities of the FMCS for the position update modes. These numbers are the result of an analysis that used existing accepted industry error characteristics of the VOR and DME and combined them based on the update mode. The IRS error model, for less than three hours following position updating, was developed by Boeing to account for the Schuler affect of the IRS, which is better than the 2nm/hr model accepted by the industry. Values for each mode are given as a range of possible ANP values or typical ANP values. NAVIGATION POSITION UPDATE MODE IRS/GPS IRS/LOC/(DME) IRS/DME/DME IRS/VOR/DME IRS RANGE OF ANP VALUES OR TYPICAL ANP VALUES HIL [0.08 to 0.27] NM, results in ANP [0.05 to 0.5] NM (dual FMC) This assumes a colinear DME with the localizer to provide along track position correction. The LOC updating starts at 20 NM from the localizer. Typical ANP; 0.0 to 0.20 NM This covers a DME/DME included angle range of 50 to 30 degrees. Range of ANP; 0.20 to 0.70NM This covers the VOR/DME update within 25nm of the navaid. Range of ANP; 0.50 to.00 NM This covers the time period after loss of radio updating. ANP is based on the 95% IRS drift characteristics and FMC compensation. It can be bounded by the following approximation for a single IRU-FMC navigation system). 0.0 to 0.67 hours; 95%ERROR = 6.0* T NM 0.67 to.5 hours; 95% ERROR = 4.0 NM.5 to 2.7 hours; 95% ERROR = * (T -.5) NM 2.7 to 3.0 hours; 95% ERROR = 6.0 NM hours; 95% ERROR = * (T - 3) NM T = time in hours TOGA Position Update Typical ANP; 0.5 NM up to 0.0 NM after 5 hours without updates. For TOGA takeoffs the FMC position is updated to the runway threshold plus pilot entered bias and ANP is initialized to 0.7 NM. Figure 6.3- FMC ANP Capability Revision - D Page 22

23 7. Flight Technical Error (FTE) Flight Technical Error FTE is defined as the ability of the pilot or the avionics to fly the airplane to the selected path. The data in Figure 7.- is from the Boeing study of the 737 flight technical error for LNAV. The Enroute data is used directly, and the terminal area data from the study is used for Approach. Consequently, the Approach data in Figure 7.- is conservative, relative to the final approach performance achievable for LNAV. Flight Technical Error (FTE) 95% Mode of Flight Enroute Approach Manual Flight with the NM NM EHSI MAP LNAV with the Flight 0. NM NM Director Coupled LNAV with the Autopilot Coupled NM NM Figure 7.- Flight Technical Error Revision - D Page 23

24 8. FMCS AFM The following are the AFM words for the Dual FMC that define the navigation capability available through the FMCS: The Flight Management Computer System has been demonstrated to meet the applicable requirements for a multi-sensor area navigation system when operated with radio or Global Position System (GPS) updating. When operated in this configuration, the FMCS may be used for enroute and terminal area operations and instrument approach navigation (excluding ILS, LOC, LOC-BC, LDA, SDF, and MLS). For a flight operation without an RNP, the FMCS with the EHSI MAP display has been demonstrated for enroute and terminal area flight operations and instrument approach navigation (excluding ILS, LOC, LOC- BC, LDA, SDF, and MLS). For Required Navigation Performance (RNP) operations, the demonstrated RNP is as follows: Minimum Demonstrated RNP Flight Operations Versus Mode of Flight Mode of Flight FMC GPS Enabled FMC GPS Not Enabled LNAV with A/P Engaged 0. NM 0.9 NM LNAV with F/D 0.2 NM 0.24 NM Manual Control with MAP Display Only 0.48 NM.0 NM The demonstrated RNP capabilities are predicated upon the assumptions, definitions, requirements, and analysis in Boeing Document D , "RNP Capability of FMC Equipped 737, Generation 2" An RNP flight operation may be subject to GPS satellite availability and/or navaid coverage for the selected route. GPS updating must be disabled for approach operation when operating outside the United States National Airspace, if the FMC database and charts are not referenced to WGS-84 reference datum, unless other appropriate procedures are used. The FMCS complies with the requirements for multi-sensor instrument approach navigation, when operated with the following RNP values: Approach Type NDB, NDB/DME VOR, VOR/DME RNAV GPS RNP 0.6nm 0.5nm 0.5nm 0.3nm Two Inertial Reference Systems (IRS) in conjunction with two Flight Management Computer Systems (FMCS) meet the applicable requirements for long range navigation. Two FMCs, two CDUs, two sensors capable of meeting a selected RNP, and two IRUs operational at dispatch are required for primary means RNP navigation. The FMCS has been demonstrated for vertical navigation (VNAV) for enroute and terminal area operation and instrument approaches (excluding ILS G/S). Revision - D Page 24

25 Fuel management and range calculation values presented by the FMCS have not been evaluated by the FAA. 8. Rationale for AFM Words The minimum RNP values for each mode of operation in the AFM were determined based on two factors. The first is the ability of the pilot to fly the airplane to the selected path (i.e. FTE). The second is when to provide the pilot with a warning that the ANP of the position being used to fly the airplane does not meet the RNP for the selected route. The minimum RNP value in the proposed AFM is the RNP that is entered on the POS SHIFT 3/3 or RTE LEGS pages. The minimum RNP values proposed for each mode of flight are based on the tables in sections 0. and 0.2. By selecting these minimum RNP values, an RNP containment threshold of RNP times two will be protected, such that FTE and navigation position determination error will be included. Annunciation that ANP is greater than RNP will indicate that the FMC position used as the reference for FTE indications is no longer adequate to ensure protection of the containment threshold for the selected RNP. The table of equivalent RNP values for approach operation is from section 0.3. These values provide equivalent navigation performance (accuracy and integrity), without the use or pilot monitoring of a procedure specified navigation update source for the FMC. Revision - D Page 25

26 9. Proposed FMCS MMEL The following are preliminary GPS, FMCS and IRS MMEL updates for FMCS: GPS requirements; 0 GPSSU operational for routes in which the accuracy requirements for the route don't require GPS for navigation. GPSSU must be operational for routes in which the accuracy requirements for the route can only be met by GPS and supplementary means navigation is required. 2 GPSSU must be operational for routes in which the accuracy requirements for the route can only be met by GPS and primary means navigation is required. FMCS requirements; FMC must be operational for routes in which the accuracy requirements for the route can only be met by FMC RNAV and supplementary means navigation is required. 2 FMCs must be operational for routes that include RNP flight operations or routes in which the accuracy requirements can only be met by FMCS primary means navigation (RNAV or oceanic). IRS requirements; The existing MMEL requirement for 2 IRUs to be operational meets all the requirements for the navigation system. Revision - D Page 26

27 0. Possible Application of RNP RNP will be an integral tool used in the planning of airspace, routes, procedures, operations and approaches. Following are two examples of how RNP might be applied to two different types of flight operations. Other applications for RNP will be devised in the future by PART 2 operations authorities and the airlines, once RNP functionality is available. 0. Enroute/Terminal Route Separation Airplanes with RNP functionality will be able to fly routes with reduced lateral separation. The reduced separation will provide increased route capacity. This will provide the following benefits to the airlines: ) Improve "on-time" performance through the use of more direct and optimal routing. 2) Increase number of available routes for crossing the Atlantic and Pacific. 3) Increase number of airplanes that can safely fly on a particular route, airway or airspace. This will provide the following benefits to the ATC agencies: ) Reduced route congestion on existing airway structure, by increasing the number of available routes. 2) Increased safety by providing better method for the flight crew to monitor compliance with route requirements. The requirement for route separation is that aircraft not exceed lateral containment threshold of 2* RNP with a probability of E-5 per flight hour. The lateral containment threshold shall account for FTE, ANP, and path definition. The following assumptions are made for this analysis:. FTE has a normal distribution. 2. ANP has a Rayleigh distribution. 3. FTE and ANP are independent. 4. Path definition error is negligible. [The basis for this assumption is that a reliable, repeatable, and predictable path is assured or mitigated by the following: Flight plans for RNP routes and procedures are comprised of specific, permissible leg types consistent with those being prescribed by industry groups such as SC 8. These leg types are direct to a fix (DF), course to a fix (CF), track to a fix (TF), initial fix (IF), and holding patterns (HX). Even in the case of these permissible leg types, the path definition error contribution may need further evaluation for the planned RNP operation considering the earth model, fix resolution, turn radius resolution, course resolution and/or magnetic variation that apply to each leg type. Surveys, fixes, procedure design, ATC coordination, testing/demonstration, crew qualification/training, crew procedures, obstacle assessments, and fly ability are evaluated for their acceptability for the planned RNP level and operation.] Two cases must be considered when determining the minimum RNP. The first case is for no navigation data error or sensor input failures and an alert is issued when ANP exceeds RNP. The second case is when a navigation data error or sensor input failure has occurred and an alert is issued when ANP exceeds RNP. For both cases the minimum RNP is determined by solving the following equation for RNP with ANP equal to RNP: 2*RNP = ((ANP CT)^2+(FTE CT)^2)^0.5 Revision - D Page 27

28 Where: ANP CT is the Rayleigh distributed ANP containment radius scaled to a normal distribution containment threshold. FTE CT is the normal distributed FTE for an equivalent probability as ANP CT. With GPS updating the following are used to solve for minimum RNP : Case : GPS updating with no failure and alert issued. ANP CT probability is 99.9% ANP CT = (3.29/2.45) * (0.7 * ANP) ANP CT = 0.95 * ANP [99.9% ANP CT is used instead of a % ANP CT due to the conditional probability that an "UNABLE REQD NAV PERF-RNP" alert will not be issued for RNP.0 with a 99% probability based on the worldwide availability of RNP with 2 satellites operational as shown in section 6.. The 0.7 is the conservatism in displayed ANP (HIL based).] FTE CT probability is 99.9% FTE CT = (3.29/.96) * FTE FTE CT =.68 * FTE Minimum RNP =.68 * FTE / SQRT (4-0.95^2) Minimum RNP = 0.96 * FTE Case 2: GPS updating with failure and alert issued. ANP CT =.80 * ANP FTE CT probability is 90% FTE CT = (.64/.96) * FTE FTE CT = 0.84 * FTE [(.80*ANP) is the bound on the error introduced by the GPS failure.] [90% containment is used instead of % containment, since the probability of a satellite failure is E-4 per flight hour] Minimum RNP = 0.84 * FTE / SQRT (4 -.80^2) Minimum RNP = 0.96 * FTE Mode of Flight Case Minimum RNP Case 2 Minimum RNP Minimum RNP LNAV with Autopilot Engaged 0.05 NM 0.05 NM 0.05 NM LNAV with Flight Director 0. NM 0. NM 0. NM Manual Control with MAP display only 0.48 NM 0.48 NM 0.48 NM Figure 0.- Minimum RNP With GPS Updating - Enroute & Terminal Operations For radio updating the following are used to solve for minimum RNP: Revision - D Page 28

29 Case : Radio updating no failure and alert issued. ANP CT probability is % ANP CT = (4.42/2.45)*(0.95)* ANP ANP CT =.7 * ANP [(0.95*ANP) is the conservatism in the ANP derived from the largest of North or East position uncertainty] FTE CT probability is % FTE CT = (4.42/.96) * FTE FTE CT = 2.25 * FTE Minimum RNP = 2.25 * FTE / SQRT (4 -.7^2) Minimum RNP = 2.7 * FTE Case 2: Radio updating with failure and alert issued. ANP CT =.02 * ANP FTE CT probability is 99.0% FTE CT = (2.58/.96) * FTE FTE CT =.32 * FTE [Radio validation criteria will reject radio position data with errors in excess of ANP from the current FMC position.] [99.0% FTE CT is used instead of a % FTE CT due to the conditional probability that navigation data or a sensor has failed is assumed to be E-3 per flight hour.] Minimum RNP =.32 * FTE / SQRT (4 -.02^2) Minimum RNP = 0.77 * FTE Mode of Flight Case Minimum RNP Case 2 Minimum RNP Minimum RNP LNAV with Autopilot Engaged 0.2 NM 0.04 NM 0.2 NM LNAV with Flight Director 0.24 NM 0.08 NM 0.24 NM Manual Control with MAP display only.0 NM 0.38 NM.0 NM (RNP 0.2 is not achievable without GPS, since the position fixing error is at least 0.2nm for multi-dme updating) Figure 0.-2 Minimum RNP Without GPS Updating- Enroute & Terminal Operations Route separation could be reduced for systems complying with smaller RNPs, for example a navigation system capable of Primary Means RNP 4.0. An RNP 4.0 has a limiting containment threshold of 8.0 NM. This flight operation could be accomplished with the FMCS if an RNP of 4.0 is selected on the CDU, using any mode of flight with sufficient navigation signal availability per the proposed AFM (Section 8.). A buffer surface between the containment radius could be added to provide increased safety for the initial implementation. Once operational experience is gained to prove the system, the buffer surface can be reduced eventually to zero. This would result in the minimum route separation for two parallel RNP 4.0 routes of 6.0 NM. This same concept could also be applied to two parallel RNP.0 routes. RNP.0 has a limiting containment threshold of 2.0 NM, therefore route separations of 4.0 NM could be realized. Revision - D Page 29

30 Further analysis of this method of route separation coupled with the definition for RNP, and the fact the airplane position within the containment radius are independent result in greater than a E-0 probability per flight hour of a catastrophic event (collision). These results are consistent with the FAR requirements. Revision - D Page 30

31 0.2 Terminal/Approach Obstacle Clearance RNP capable airplanes will be able to fly departure, terminal approach transition and approach procedures with reduced obstacle clearance requirements. The reduced obstacle clearance requirement will provide increased availability of these IFR procedures at the airports by reducing minima and visibility requirements. The reduced obstacle clearance requirements will provide benefits to the airlines and the ATC authorities. The airlines will reduce flight cancellations and improve "on-time" performance by having a higher availability of procedures to get in and out of airports. The ATC agencies will have an increased number of procedures available to them to spread the air traffic more evenly, reduce the amount of congestion in the terminal area, and provide a greater number of procedures for getting into and out of airports, thereby increasing safety in the terminal area. With GPS updating the following are used to solve for minimum RNP : Case : GPS updating with no failure and alert issued. ANP CT probability is % ANP CT = (4.56/2.45) * (0.7 * ANP) ANP CT =.32 * ANP [ % ANP CT is used instead of a % ANP CT due to the conditional probability that an "UNABLE REQD NAV PERF-RNP" alert will not be issued for an for RNP 0.5 with a 80% probability based on the worldwide availability of RNP with 2 satellites operational as shown in section 6.. The 0.7 is the conservatism in displayed ANP (HIL based).] FTE CT probability is % FTE CT = (4.89/.96) * FTE FTE CT = 2.49 * FTE Minimum RNP = 2.49 * FTE / SQRT (4 -.32^2) Minimum RNP =.66 * FTE Case 2: GPS updating with failure and alert issued. ANP CT =.80 * ANP FTE CT probability is 99% FTE CT = (2.58/.96) * FTE FTE CT =.32 * FTE [(.80*ANP) is the bound on the error introduced by the GPS failure.] [99% containment is used instead of % containment, since the probability of a satellite failure is E-4 per flight hour] Minimum RNP =.32 * FTE / SQRT (4 -.80^2) Minimum RNP =.5 * FTE Revision - D Page 3