11-1 CHAPTER 11. AIRCRAFT AND SYSTEM REQUIREMENTS
11.1 References. Refer to the appendices below for aircraft and system requirements:
1. Appendix A , Qualification Criteria for Required Navigation Performance Approach (RNP APCH) Operations.
2. Appendix B , Use of Barometric Vertical Navigation (baro-VNAV) for Required Navigation Performance Approach (RNP APCH) Operations.
3. Appendix C , Qualification Criteria for Required Navigation Performance (RNP) 1 (Terminal) Operations.
4. Appendix D , Qualification Criteria for Required Navigation Performance (RNP) 0.3 (Rotorcraft) Operations.
5. Appendix E , Qualification Criteria for Required Navigation Performance (RNP) 2 Domestic, Offshore, Oceanic, and Remote Continental Operations.
6. Appendix F , Qualification Criteria for Required Navigation Performance (RNP) 4 Oceanic and Remote Continental Operations.
7. Appendix G , Qualification Criteria for Required Navigation Performance (RNP) 10 Oceanic and Remote Continental Operations.
8. Appendix H , Advanced Required Navigation Performance (A-RNP).
9. Appendix I, Additional Capabilities.
12-1 CHAPTER 12. BUNDLING CONCEPT
12.1 Performance-based Navigation (PBN) Authorization. The Federal Aviation Administration (FAA) allows PBN authorizations to be bundled. This concept provides the FAA more latitude in granting a wider range of authorizations on a single operator application. Each flight phase contains a hierarchy of PBN authorizations where bundling can be accomplished. PBN authorizations within an operation specification (OpSpec), management specification (MSpec) or Letter of Authorization (LOA) are combined with less restrictive PBN authorization(s) within each phase of flight, if applicable. This reduces cost and workload for both the operator and the FAA.
12.2 Visual of Bundling Options. Figure 12-1, Bundling Options, illustrates this concept of bundling by flight phase into approach, terminal, en route, and oceanic/remote continental. Each phase contains a hierarchy of PBN operations within the applicable OpSpec, MSpec, or LOA.
12.3 Approach Phase Composition. The approach phase has two distinct divisions of Required Navigation Performance Authorization Required Approach (RNP AR APCH) and Required Navigation Performance Approach (RNP APCH). For the purpose of bundling, Required Navigation Performance Authorization Required (RNP AR) is excluded from bundling because of unique requirements for authorization.
Note: Localizer performance with vertical guidance (LPV) and localizer performance without vertical guidance (LP) minimums are authorized through OpSpec/MSpec/LOA C052, but are excluded as a bundling option.
12.4 Credit for Existing RNP AR Approvals. Operators with a current and approved RNP AR approval meet the requirements the Required Navigation Performance (RNP) operations as described in this advisory circular (AC).
12.5 RNP 2 Areas of Operation. The Areas of Operation for RNP 2 are within the U.S. National Airspace System (NAS) or offshore airspace where domestic air traffic control (ATC) procedures are applied and also in oceanic and remote continental airspace.
Note: Oceanic and remote continental airspace often have additional surveillance, communication, and higher navigation continuity requirements.
12.6 Terminal and En Route Phases of Flight. The terminal and en route phases of flight contains RNP 1, RNP 2, Area Navigation (RNAV) 1, RNAV 2, and RNAV 5 for terminal and en route operations (see Figure 12-1). An operator with an RNP 1 authorization as described in Appendix C, Qualification Criteria for Required Navigation Performance (RNP) 1 (Terminal) Operations, would also be granted authorization for RNAV 1.
Additionally, an RNP 2 (domestic) authorization as described in Appendix E, Qualification Criteria for Required Navigation Performance (RNP) 2 Domestic, Offshore, Oceanic, and Remote Continental Operations, would also be granted RNAV 2 and RNAV 5 authorizations.
12-2
12.7 Oceanic/Remote Continental RNP 2 Authorization. An operator with an oceanic/remote continental RNP 2 authorization (Figure 12-1) will also be granted RNP 4 and RNP 10 navigation authorizations. Authorizations in oceanic and remote continental airspace also depend upon the operator’s qualification to meet international surveillance and communication requirements. Those requirements are specified in other documents, such as the Aeronautical Information Publications (AIP) and the International Civil Aviation Organization (ICAO) Doc 7030, Regional Supplementary Procedures (SUPPS) and AC 91-70( ), Oceanic and International Operations.
12.8 Advanced Required Navigation Performance (A-RNP). In order to be A-RNP qualified (see Appendix H, Advanced Required Navigation Performance (A-RNP)), operators must be operationally and functionally qualified to perform the following three required functions:
1. Scalability,
2. Radius to Fix (RF), and
3. Parallel offset.
Note: Higher continuity may be required for oceanic and remote continental airspace. Currently, fixed radius transition (FRT) and Time of Arrival Control (TOAC) are optional. For each applicable OpSpec, MSpec, or LOA, A-RNP functions are added to the bundled hierarchy of PBN authorizations (see Figure 12-1).
Figure 12-1. Bundling Options Bundling Options Approach Oceanic/ RNP AR APCH RNP APCH Terminal En Route Remote/SAO * Approach Approach OpSpec/MSpec OpSpec/MSpec OpSpec/MSpec OpSpec/MSpec OpSpec/MSpec C384 C052 C063 B035 B036 Advanced RNP RNP .XX LNAV/ RNP 1 RNP 2 RNP 2 VNAV RNAV 1 RNAV 2 RNP 4 LNAV RNAV 5 RNP 10 (Multi LRNS) C052 B054 LPV (SBAS only) RNP 10 LP (SBAS only) Additional communication, surveillance, and higher continuity requirements may be required 12-3
Appendix A A-1 APPENDIX A. QUALIFICATION CRITERIA FOR REQUIRED NAVIGATION
PERFORMANCE APPROACH (RNP APCH) OPERATIONS A.1 Introduction. This appendix provides guidance on the performance and functional requirements for systems used to conduct RNP APCH operations, which are designated under Title 14 of the Code of Federal Regulations (14 CFR) part 97 as Area Navigation (RNAV) Global Positioning System (GPS) or GPS and categorized as RNP APCH by the International Civil Aviation Organization (ICAO). Localizer performance without vertical guidance (LP) and localizer performance with vertical guidance (LPV) operations can be found in Advisory Circular (AC) 90-107( ), Guidance for Localizer Performance with Vertical Guidance and Localizer Performance without Vertical Guidance Approach Operations in the U.S. National Airspace System. The barometric vertical navigation (baro-VNAV) aspects of RNP APCHs are specified in Appendix B, Use of Barometric Vertical Navigation (baro-VNAV) for Required Navigation Performance Approach (RNP APCH) Operations. Baro-VNAV systems are optional capabilities that are not a minimum requirement to fly RNAV (GPS) or GPS approaches using the lateral navigation (LNAV) line of minima. The requirements for Radius to Fix (RF) legs are specified in Appendix I, Additional Capabilities.
A.2 Aircraft and System Requirements.
A.2.1 Approval for RNAV (GPS) or GPS Approaches. Aircraft with approval to conduct RNAV (GPS) or GPS approaches meet the performance and functional requirements in this AC for RNP APCH instrument approaches without RF legs.
A.2.2 Statement of Compliance (SOC). Aircraft with a SOC with the criteria in this AC in their Airplane Flight Manual (AFM), Airplane Flight Manual Supplement (AFMS), pilot’s operating handbook (POH), or the operating manual for their avionics meet the performance and functional requirements of this AC.
A.2.3 Statement from the Manufacturer. Aircraft with a statement from the manufacturer documenting compliance with the criteria in AC 20-138( ), Airworthiness Approval of Positioning and Navigation Systems, meet the performance and functional requirements of this AC. Manufacturer documentation can include Service Bulletins (SB) or Service Letters (SL). These statements should include the airworthiness basis for compliance.
AFM/Rotorcraft Flight Manual (RFM) entries are not required provided the Federal Aviation Administration (FAA) accepts the manufacturer’s documentation.
A.2.4 Qualified Avionics Equipment and Airworthiness Approval. Aircraft with the following avionics equipment and an appropriate airworthiness approval automatically qualify for RNP APCH to LNAV minima capability without further documentation by virtue of the avionics Technical Standard Order (TSO) and airworthiness approval:
1. GPS stand-alone systems approved in accordance with TSO-C129( ), Class A1, or TSO-C146 operational Class 1, 2, or 3 and installed in accordance with AC 20-138( ).
Appendix A A-2
2. Aircraft with a TSO-C115c or later flight management system (FMS) with a TSO-C129( ) (Class B1, C1, B3, C3), TSO-C145( ), or TSO-C196( ) sensors installed in accordance with AC 20-138( ).
3. Aircraft with a TSO-C115b FMS using a TSO-C129( ) Class B1/C1, TSO-C145( ), or TSO-C196( ) sensor with documented compliance to the RNP requirements in RTCA, Inc.’s document, RTCA/DO-236 (revision ‘B’ or later) or RTCA/DO-283 (revision ‘A’ or later) as part of the approval basis.
A.2.5 GPS-Equipped Multisensor Systems. Multisensor systems using GPS should be approved in accordance with AC 20-138( ) or TSO-C115b or later and meet the functionality requirements of this appendix. Multisensor systems that use distance measuring equipment (DME)/DME or DME/DME/Inertial Reference Unit (IRU) as the only means of Required Navigation Performance (RNP) compliance are not authorized to conduct RNP APCHs. However, operators still retain the option to develop special RNP APCHs using these systems.
A.2.6 Other Equipment. For equipment other than what is listed in paragraph A.2, the Original Equipment Manufacturer (OEM) or the holder of installation approval for the aircraft
(e.g., Supplemental Type Certificate (STC) holder) must demonstrate compliance with the criteria in this AC.
A.3 Performance and Functionality Requirements for RNP APCH Systems.
A.3.1 Accuracy. The aircraft must comply with Section 2.1.1 of RTCA/DO-236C. During operations on the initial and intermediate segments and for the missed approach of an RNP APCH procedure, the lateral Total System Error (TSE) must be within ±1 nautical mile (NM) for at least 95 percent of the total flight time. The along-track (ATRK) error must also be within ±1 NM for at least 95 percent of the total flight time.
Note: There are no RNP requirements for the missed approach if it is based on conventional means (very high frequency omni-directional range (VOR), DME, and Non-Directional Beacon (NDB)) or on dead reckoning.
A.3.1.1 During operations on the Final Approach Segment (FAS), the lateral TSE must be within ±0.3 NM for at least 95 percent of the total flight time. The ATRK must also be within ±0.3 NM for at least 95 percent of the total flight time.
A.3.1.2 To satisfy the accuracy requirement, the 95 percent Flight Technical Error (FTE) should not exceed 0.5 NM on the initial and intermediate segments, and for the RNAV missed approach, of an RNP APCH. The 95 percent FTE should not exceed 0.25 NM on the FAS of an RNP APCH.
Note: The use of a deviation indicator with 1 NM full-scale deflection on the initial and intermediate segments, and for the RNAV missed approach and 0.3 NM full-scale deflection on the FAS, has been found to be an acceptable means of compliance (AMC). The use of an
Appendix A A-3 autopilot (AP) or flight director (FD) has been found to be an AMC (roll stabilization systems do not qualify).
A.3.2 Integrity. Malfunction of the aircraft navigation equipment that causes the TSE to exceed 2 times the RNP APCH value is classified as a major failure condition under airworthiness regulations (i.e., 10-5 per hour).
A.3.3 Continuity. Loss of function is classified as a minor failure condition if the operator can revert to a different navigation system and safely proceed to a suitable airport.
A.3.4 Performance Monitoring and Alerting. During operations on the initial, intermediate, and the missed approach segment, the RNP system or the RNP system and pilot in combination must provide an alert if the accuracy requirement is not met or if the probability that the lateral TSE exceeds 2 NM is greater than 10-5. During operations on the FAS, the RNP system or the RNP system and pilot in combination must provide an alert if the accuracy requirement is not met or if the probability that the lateral TSE exceeds 0.6 NM is greater than 10-5.
A.3.5 Signal in Space (SIS). During Global Navigation Satellite System (GNSS) operations on the initial, intermediate, and missed approach segments, the aircraft navigation equipment must provide an alert if the probability of SIS errors causing a lateral position error greater than 2 NM exceeds 10-7 per hour. During GNSS operations on the FAS, the aircraft navigation equipment must provide an alert if the probability of SIS errors causing a Navigation System Error (NSE) greater than 0.6 NM exceeds 10-7 per hour.
Note 1: There are no RNP requirements for the missed approach if it is based on conventional means (VOR, DME, and NDB) or on dead reckoning.
Note 2: Aircraft with an approved multisensor RNP system where GNSS integrity is incorporated into an RNP integrity alert consistent with DO-236( ) do not require a separate GNSS integrity alert when performance cannot be met.
A.3.6 Path Definition. Aircraft performance is evaluated around the path defined by the published procedure and RTCA/DO-236C.
A.3.7 Functional Requirements of Navigation Displays. The following navigation displays and functions are required, as installed in accordance with AC 20-138( ) or equivalent system installation advisory material. Navigation data, including a TO/FROM indication and a failure indicator, must be displayed on a lateral deviation display, course deviation indicator (CDI), electronic horizontal-situation indicator (EHSI), and/or a navigation map display. These must be used as primary flight instruments for aircraft navigation, for maneuver anticipation, and for failure/status/integrity indication.
A.3.7.1 RNP systems using TO/TO navigation algorithms do not require a navigation display with a TO/FROM indication during RNP instrument procedures.
Displays supporting TO/TO navigation computers can fully comply with all RNP-related criteria in this AC without a TO/FROM indication. At a minimum, the navigation display supporting a TO/TO RNP system should
Appendix A A-4 display the active waypoint and active waypoint name. However, TO/TO RNP systems must have the ability accommodate route discontinuities and continue providing navigation information.
A.3.7.2 A non-numeric lateral deviation display (e.g., CDI, EHSI), with TO/FROM indication and a failure annunciation, used as primary flight instruments for aircraft navigation, for maneuver anticipation, and for failure/status/integrity indication, should have the following attributes:
1. The displays must be visible to the pilot and located in the primary field of view (FOV) when looking forward along the flightpath.
2. The lateral deviation display must have a full-scale deflection suitable for the current phase of flight and must be based on the TSE requirement. Scaling of ± 1 NM for the initial, intermediate, and missed approach segments and ±0.3 NM for the final segment is acceptable. It is also acceptable for the scaling to be more conservative than the TSE (e.g., ±0.3 NM for the initial, intermediate, and missed approach segments).
3. The display scaling may be set automatically by default logic or set to a value obtained from a navigation database. The full-scale deflection value must be known or must be available for display to the pilot commensurate with approach values.
4. The lateral deviation display must be automatically slaved to the RNP-computed path. It is recommended that the course selector of the deviation display be automatically slewed to the RNP-computed path.
Note: This does not apply for installations where an electronic map display contains a graphical display of the flightpath and path deviation.
5. As an alternate means, a navigation map display must provide equivalent functionality to a lateral deviation display with appropriate map scales (scaling may be set manually by the pilot).
To be approved as an alternative means, the navigation map display must be shown to meet the TSE requirements and be located in the primary FOV.
6. It is not necessary for navigation displays, particularly primary flight displays (PFD), to include an Actual Navigation Performance (ANP) or Estimate of Position Error (EPE) value. The displays only need to provide an alert if the RNP for the operation cannot be met.
Appendix A A-5 A.3.8 System Capabilities. The following system capabilities are required as a minimum:
1. The capability to continuously display to the pilot flying (PF), on the primary flight instruments for navigation of the aircraft (primary navigation display), the RNP APCH-computed desired path, and aircraft position relative to the path. For operations where the required minimum flightcrew is two pilots, a means for the pilot monitoring (PM) to verify the desired path; and the aircraft position relative to the path must also be provided.
2. A navigation database, containing current navigation data officially promulgated for civil aviation, which can be updated in accordance with the Aeronautical Information Regulation and Control (AIRAC) cycle. The stored resolution of the data must be sufficient to achieve the required track-keeping accuracy. The database must be protected against pilot modification of the stored data.
3. The means to display the validity period of the navigation data to the pilot.
4. The means to retrieve and display data stored in the navigation database relating to individual waypoints and navigation aids, to enable the pilot to verify the route to be flown.
5. Capability to load from the database into the RNP system the whole approach to be flown. The approach must be loaded from the database, into the RNP system, by its name.
Note: Numeric values for database defined procedures must be automatically loaded from the RNP system database.
6. The means to display the following items, either in the pilot’s primary FOV, or on a readily accessible display page:
• Distance between flight plan waypoints,
• Distance to go to the waypoint selected by the pilot,
• Active navigation sensor type,
• The identification of the active (To) waypoint,
• The ground speed or time to the active (To) waypoint, and
• The distance and bearing to the active (To) waypoint.
7. The capability to execute a “Direct to” function.
8. The capability for automatic leg sequencing with display to the pilots.
9. The capability to execute an RNP APCH instrument approach procedure (IAP) extracted from the onboard database, including the capability to execute flyover and flyby turns.
Appendix A A-6
10. The capability to automatically execute leg transitions and maintain tracks consistent with the following Aeronautical Radio, Inc. (ARINC) 424 path terminators, or their equivalent:
• Initial Fix (IF),
• Track to Fix (TF), and
• Direct to Fix (DF).
Note: Path terminators are defined in ARINC Specification 424, and their application is described in more detail in RTCA, Inc. documents, DO-236( ) and DO-201( ).
11. The capability to display an indication of the RNP system failure, in the pilot’s primary FOV.
12. The capability to indicate to the crew when the NSE or Position Estimation Error (PEE) alert limit is exceeded (alert provided by the onboard performance monitoring and alerting function).
13. The system must allow for a means to become established prior to the final approach fix (FAF) on an instrument landing system (ILS) or Ground Based Augmentation System (GBAS) Landing System (GLS) with minimal overshoot or undershoot.
A.3.9 FD/AP. For aircraft equipped with FD and/or AP, it is recommended the FD is engaged and/or AP remain coupled for RNP APCH. If the lateral TSE cannot be demonstrated without these systems, then coupling becomes mandatory. In this instance, operating guidance must indicate FD engagement and/or automatic pilot coupling from the RNP system is mandatory for approaches.
A.4 Database.
A.4.1 Database Integrity. The operator must ensure their navigation database supplier possesses a Type 2 Letter of Acceptance (LOA) in accordance with AC 20-153( ), Acceptance of Aeronautical Data Processes and Associated Databases.
A.4.2 Path Terminators. The database supplier should not substitute path terminators in lieu of those specified in the original State Aeronautical Information Publication (AIP) data.
A.5 Special Characteristics of RNP APCH Instrument Approaches.
A.5.1 Navigational Aid (NAVAID) Infrastructure. GPS is the primary navigation system to support RNP APCH procedures. DME/DME-based systems are not acceptable for RNP APCH. The missed approach segment may be based upon a conventional NAVAID
(e.g., VOR, DME, and NDB).
A.5.2 Lines of Minima. RNP APCH may have multiple lines of minima. This appendix addresses the LNAV and LNAV/vertical navigation (VNAV) lines of minima. In
Appendix A A-7 addition, the use of baro-VNAV for an RNP APCH to the LNAV/VNAV minima is addressed in Appendix B. Reference AC 90-107( ) for an RNP APCH to the LP and LPV lines of minima.
Note: AC 20-138( ) addresses aircraft integration that includes baro-VNAV and GPS/Satellite-based Augmentation System (SBAS) and/or GPS/Ground Based Augmentation System (GBAS) for vertical guidance.
A.6 Aircraft Eligibility for RNP APCH Operations.
A.6.1 Introduction. The OEM or the holder of installation approval for the aircraft
(e.g., STC holder) must demonstrate compliance with the appropriate provisions of this AC to the Federal Aviation Administration (FAA), and the approval can be documented in manufacturer documentation (e.g., SLs, etc.). AFM/RFM entries are not required.
A.6.2 System Eligibility for RNP APCH LNAV and LNAV/VNAV Minima. Systems meeting the requirements in AC 20-138( ) are eligible for RNP APCH operations. Aircraft qualified by AC 90-101( ), Approval Guidance for RNP Procedures with AR, are considered qualified for RNP APCH operations without further examination.
A.6.3 LNAV Line of Minima Qualification.
A.6.3.1 Stand-Alone Systems. Stand-alone systems meeting TSO-C129a Class A1 or TSO-C146( ) Class 1, 2, or 3 meet the aircraft qualification requirements for RNP APCH operations using the LNAV line of minima provided the instrument flight rules (IFR) installations were performed in accordance with AC 20-138( ).
A.6.3.2 Multisensor Systems. Multisensor systems using TSO-C196, TSO-C129a Class B1, B3, C1, or C3, or TSO-C145 Class 1, 2, or 3 sensors meet the aircraft qualification requirements for RNP APCH operations using the LNAV line of minima, provided the installations meet the criteria of this AC and Appendix A, the associated FMS complies with TSO-C115b or later and are installed in accordance with AC 20-138( ).
A.6.4 LNAV/VNAV Line of Minima Qualification.
A.6.4.1 Stand-Alone Systems. Stand-alone TSO-C146 Class 2 or 3 systems meet the aircraft qualification requirements for RNP APCH operations using the LNAV/VNAV line of minima provided that the installations meet at least the performance and functional requirements of this AC.
A.6.4.2 Multisensor Systems. Multisensor systems using TSO-C129a Class B1, B3, C1, or C3 sensors, TSO-C145 Class 1 sensors, or TSO-C196( ) with baro-VNAV meet the aircraft qualification requirements for RNP APCH operations using the LNAV/VNAV line of minima provided the installations meet the requirements of this AC (including Appendix A and Appendix B).
Multisensor systems using TSO-C145 Class 2 or 3 meet the requirements for
Appendix A A-8 RNP APCH operations to LNAV/VNAV minima without baro-VNAV when using SBAS-based vertical guidance. The RNP systems including the FMS must be installed in accordance with AC 20-138( ) and the associated FMS must comply with TSO-C115b or later.
A.6.4.3 Demonstrations. Demonstration of aircraft performance in accordance with AC 20-138( ) does not constitute operations approval to conduct RNP operations.
A.7 Operational Considerations.
A.7.1 Preflight Planning.
A.7.1.1 Operators and pilots intending to conduct operations on RNP APCH IAPs must file the appropriate flight plan suffixes.
A.7.1.2 At system initialization, pilots must confirm the navigation database is current and includes appropriate procedures. Pilots must also verify that the aircraft position is correct.
Note 1: Navigation databases are expected to be current for the duration of the flight. If the AIRAC cycle is due to change during flight, operators and pilots should establish procedures to ensure the accuracy of navigation data, including suitability of navigation facilities used to define the routes and procedures for flight. This may be accomplished by verifying electronic data against paper or Electronic Flight Bag (EFB) products. One acceptable means is to compare aeronautical charts (new and old) to verify navigation fixes prior to dispatch. If an amended chart (hard copy amendment not in the database) is published for the procedure, the database must not be used to conduct the operation.
Note 2: On U.S. IAPs only, the “Procedure Amendment Effective Date” may be used to ensure the accuracy of the navigation data contained in an expired database. If the Procedure Amendment Effective Date falls on or after the navigation database expiry date, the procedure should not be flown using the out-of-date database.
A.7.1.3 Pilots must verify proper entry of their air traffic control (ATC)-assigned route upon initial clearance and any subsequent change of route. Pilots must ensure the waypoint sequence depicted by their navigation system matches their assigned route and the route depicted on the appropriate chart(s).
A.7.1.4 The flightcrew may notice a slight difference between the navigation information portrayed on the chart and their primary navigation display.
Differences of 3 degrees or less may result from equipment manufacturer’s application of magnetic variation and are operationally acceptable.