Appendix G G-1 APPENDIX G. QUALIFICATION CRITERIA FOR REQUIRED NAVIGATION PERFORMANCE (RNP) 10 OCEANIC AND REMOTE CONTINENTAL OPERATIONS G.1 Introduction. This appendix provides guidance for operation in and is intended to support 50 nautical miles (NM) lateral and the 50 NM longitudinal distance based separation minima. Previous authorizations in accordance with Federal Aviation Administration (FAA) Order 8400.12C, Required Navigation Performance 10 (RNP 10) Operational Authorization, remain valid. This appendix does not address communications or surveillance requirements that may be specified to operate on a particular route or in a particular area. 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 ICAO Doc 4444 PANS ATM, Procedures for Air Navigation Services, Air Traffic Management.
Note: Area Navigation (RNAV) 10 is designated and authorized as RNP 10. This document uses the designation of RNP 10.
G.2 Aircraft and System Requirements for RNP 10.
G.2.1 Statement of Compliance (SOC). Aircraft with an SOC with RNP 10 criteria in Advisory Circular (AC) 20-138( ), Airworthiness Approval of Positioning and Navigation Systems, 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 appendix. RNP compliance is documented in the AFM and is typically not limited to RNP 10. The AFM will address RNP, navigation specifications (Nav Specs) that have been demonstrated and any related provisions applicable to its use (e.g., Navigational Aid (NAVAID) sensor requirements).
G.2.2 Equipment. Aircraft must be equipped with at least dual navigation systems except for operation in the Gulf of Mexico (GOMEX) where Single Long-Range Navigation System (S-LRNS) RNP 10 is authorized.
G.3 System Performance.
G.3.1 Accuracy. During operations in airspace or on routes designated as RNP 10, the lateral Total System Error (TSE) must be within ±10 NM for at least 95 percent of the total flight time. The along-track (ATRK) error must also be within ±10 NM for at least 95 percent of the total flight time.
Note: For RNP 10 approval, navigation positioning error is considered the dominant contributor to cross-track (XTK) and ATRK for aircraft capable of coupling the navigation system to the flight director (FD) or autopilot (AP).
Flight Technical Error (FTE), Path Definition Error (PDE), and display error are considered to be insignificant for the purposes of RNP 10 approval (RNP 10 is intended for oceanic and remote continental areas where aircraft separation minima of 50 NM are applied).
Appendix G G-2 G.3.2 Integrity. Malfunction of the aircraft’s long-range navigation (LRN) equipment without annunciation is a major failure condition (i.e., the probability of a malfunction with no annunciation must be less than 10-5 per hour).
G.3.3 Continuity. Loss of function of the LRN equipment is a major failure condition for oceanic and remote continental operations. Dual independent long-range navigation system (LRNS) equipage may satisfy the continuity criteria (excluding Signal in Space (SIS) criteria).
G.3.4 SIS. If using Global Navigation Satellite System (GNSS), the aircraft LRN equipment must provide an alert if the probability of SIS errors causing a lateral position error greater than 20 NM exceeds 10-7 per hour.
G.4 Aircraft Eligibility.
G.4.1 Prior Navigation System Certification. Aircraft Original Equipment Manufacturers (OEM) and operators may use a prior navigation system certification to recognize an aircraft whose performance under the criteria of another RNP specification equates to or exceeds the RNP 10 performance criteria listed in AC 20-138( ). Aircraft OEMs and operators may also use other Nav Spec standards when they are sufficient to ensure compliance with RNP 10 performance criteria.
Note: Qualification through data collection guidance provided in Order 8400.12C is available in a booklet format online. Operators qualifying by the data collection methods should contact their Principal Operations Inspector (POI) and download a copy of the booklet, RNP 10 Qualification through Data Collection from the Flight Technologies and Procedures Division web page at www.faa.gov/about/offi ce_org/headquarters_offices/avs/offices/afx/afs/afs400/, Performance Based Flight Systems Branch, Oceanic and Remote Airspace (Special Areas of Operations).
G.4.2 Application Description. RNP 10 is an RNAV operational application supporting 50 NM lateral and 50 NM longitudinal distance-based aircraft separation minima in oceanic or remote continental airspace. As an RNAV application, there is no requirement for onboard performance monitoring and alerting. There are two methods to recognize aircraft and system eligibility for RNP 10 operations: 1) RNP 10 certification; and,
2) prior navigation system certification.
G.4.3 Eligibility Through an RNP 10 Certification. RNP 10 compliance is documented in the AFM and is typically not limited to RNP 10. The AFM/AFMS should document the demonstrated RNP values the aircraft supports along with any limitations
(e.g., navigation aid sensor requirements for present position updating).
Note: Aircraft qualified for RNP 4 operations automatically qualify for RNP 10 operations.
G.4.3.1 An aircraft may have an airworthiness approval specific to RNP 10 qualification. The following (or equivalent) is an example of AFM wording
Appendix G G-3 when RNP 10 approvals are granted for either a change in, or new demonstration of, the inertial navigation system (INS)/Inertial Reference Unit (IRU)-certified performance:
“The XXX navigation system meets the aircraft qualification criteria of AC 20-138( ), as a primary means of navigation for flights up to XXX hours in duration without present position updating. The determination of flight duration starts when the flightcrew places the long-range navigation system in the inertial navigation mode,” Note: The “XXX hours” specified in the AFM/AFMS for INS/IRU systems do not include credit for present position updating.
G.4.3.2 For LRNSs capable of updating the aircraft’s present position while airborne, the airworthiness approval must address the impact present position updating has on position accuracy and any impact on time limits for RNP 10 operations. The approval should clarify the role of ground-based navigation facilities in present position updating (if any), clarify the role of GNSS present position updating (if equipped), and define any requisite flightcrew procedures necessary to initiate and terminate present position updating. The credit received for present position updating can be applied to the “XXX hours” specified in the AFM/AFMS for INS/IRU systems.
G.4.3.3 Demonstration of aircraft performance in accordance with AC 20-138( ) does not constitute operations approval to conduct RNP operations.
G.4.3.4 The demonstration of inertial performance to FAA Aircraft Certification Service (AIR) forms the basis for the suggested AFM/AFMS wording above, but is only one element of the approval process. Aircraft that have this wording in their flight manual will be eligible for operational approval through issuance of operations specifications (OpSpecs)/management specifications (MSpecs) or a Letter of Authorization (LOA) (as applicable) when the operator and aircraft meet all other RNP 10 qualification criteria.
G.5 Aircraft Equipped with Two or More INS or IRUs. Inertial systems approved in accordance with Title 14 of the Code of Federal Regulations (14 CFR) part 121, Appendix G are considered to meet RNP 10 requirements for up to 6.2 hours of flight time. This time starts when the system is placed in the inertial navigation mode.
G.5.1 INS/IRU System Updates. If the flightcrew updates the INS/IRU systems en route (through manual or automatic means), the flightcrew must adjust the 6.2 hour RNP 10 time limit to account for the update’s accuracy. The flightcrew must base any adjustments to the time limit on the demonstrated capability of the updates stated in the aircraft’s airworthiness approval documentation (i.e., the AFM/AFMS).
G.5.1.1 INS/IRU accuracy, reliability, training, and maintenance issues required by an airworthiness approval in compliance with part 121, Appendix G are applicable to an RNP 10 operation, including any associated procedures
Appendix G G-4 in oceanic and remote continental airspace. Except as authorized by the FAA Administrator, and in accordance with the applicable section of 14 CFR, RNP 10 operations based solely IRS/IRU requires at least dual equipage
(i.e., two or more inertial systems). Refer to 14 CFR part 121, § 121.351, part 125, § 125.203, and part 135, § 135.165.
Note: The long-term inertial drift rate of 2.0 NM/hour (a 95 percent radial position error rate (circular error rate)) is the performance basis for the 6.2 hour time limit. This drift rate is statistically equivalent to an individual 95 percent XTK and an individual 95 percent ATRK position error rates (orthogonal error rates) of 1.6015 NM/hour each;
and, a 95 percent XTK and a 95 percent ATRK position error limit of 10 NM each (e.g., 10 NM/1.6015 NM/hour = 6.2 hours).
G.5.1.2 Aircraft approved for North Atlantic Minimum Navigation Performance Specifications (NAT/MNPS) or Australian RNAV operations meet RNP 10 criteria for up to 6.2 hours after the flightcrew places the LRNS in the inertial navigation mode.
G.5.2 Two or More INSs or IRUs – Extended Time Limit. The 6.2 hour time limit is the baseline for RNP 10 inertial systems performance, and the time limit begins when the flightcrew places the LRNS in the inertial navigation mode. However, this time limit may be extended by one of the following methods:
1. Establishing an extended time limit during a formal RNP 10 airworthiness approval process (e.g., a new type certificate (TC), amended TC, or Supplemental Type Certificate (STC) project);
2. An existing airworthiness approval holder requests an extension for the installed inertial navigation system from the responsible Aircraft Certification Service office based on justifying engineering data; or
3. An airworthiness applicant or existing airworthiness approval holder requests an extended time limit by showing how multiple navigation sensors that mix or average navigation position error justifies an extension (e.g., triple-mixed INSs). If the applicant requests an extended time limit based on mixing, then the availability of the mixing capability is a limitation for flight on RNP 10 routes. If the mixing or averaging function is not available, the operator must use a time limit that does not depend on mixing.
G.6 Route Evaluation For RNP 10 Time Limits For Aircraft Equipped Only With INS or IRU. An RNP 10 time limit must be established for aircraft equipped only with INS or IRU. When planning operations in areas where RNP 10 is applied, the operator must establish that the aircraft will comply with the time limitation on the routes that it intends to fly.
G.6.1 Time Limit Considerations. In making this evaluation, the operator must consider the effect of head winds and, for aircraft not capable of coupling the navigation system or
Appendix G G-5 FD to the AP, the operator may choose to make this evaluation on a one-time basis or on a per-flight-basis. The operator should consider the points listed in the following subsections in making this evaluation.
1. Route Evaluation. The operator must establish the capability of the aircraft to satisfy the RNP 10 time limit established for dispatch or departure into RNP 10 airspace.
2. Start Point for Calculation. The calculation must start at the point where the system is placed in navigation mode or the last point at which the system is expected to be updated.
3. Stop Point for Calculation. The stop point may be one of the following:
• The point at which the aircraft will begin to navigate by reference to ICAO standard NAVAIDs (very high frequency omni-directional range (VOR), distance measuring equipment (DME), Non-Directional Beacon (NDB)) and/or comes under Air Traffic Service (ATS) surveillance; or
• The first point at which the navigation system is expected to be updated.
4. Sources of Wind Component Data. The head wind component to be considered for the route may be obtained from any source found acceptable to the FAA. Acceptable sources for wind data include:
• The National Weather Service (NWS),
• Industry sources (e.g., Boeing Winds on World Air Routes), and
• Historical airline data supplied by the operator.
G.6.2 One-Time Calculation Based on 75 Percent Probability Wind Components. Certain sources of wind data establish the probability of experiencing a given wind component on routes between city pairs on an annual basis. If an operator chooses to make a one-time calculation of RNP 10 time limit compliance, he/she may use the annual 75 percent probability level to calculate the effect of head winds. This level has been found to be a reasonable estimation of wind components.
G.6.3 Calculation of Time Limit for Each Specific Flight. The operator may choose to evaluate each individual flight using flight-planned winds to determine if the aircraft will comply with the specified time limit. If it is determined that the flight will exceed the time limit, then the aircraft must fly an alternate route or delay the flight until it can meet the time limit. This evaluation should be considered a flight planning or dispatch task.
Appendix G G-6 G.7 Two or More GNSS Systems. Aircraft approved to use GNSS for oceanic and remote continental operations without reliance on other LRNSs are considered to meet the RNP 10 requirements without time limitations associated with INS/IRU equipment.
However, using GNSS depends upon using a fault detection and exclusion (FDE) availability prediction.
G.7.1 AFM/AFMS Documentation. Dual GNSS installations with a Technical Standard Order Authorization (TSOA) qualify for RNP 10 when the operator uses an approved dispatch GNSS FDE availability prediction. The AFM/AFMS should indicate if a particular GNSS installation meets the appropriate FAA criteria for oceanic and remote continental operations.
G.7.2 Applicable Technical Standard Order. Technical Standard Order (TSO)-C196 and TSO-C145/TSO-C146 Global Positioning System (GPS) equipment are inherently capable of supporting oceanic and remote continental operation when used in conjunction with an approved FDE prediction program.
G.7.3 Additional Required Guidance. TSO-C129( ) GPS equipment is not inherently capable of oceanic and remote continental operations. Additional criteria defining an acceptable means of compliance (AMC) for this equipment to be approved for this operation is located in AC 20-138( ), Appendix 1. The AFM/AFMS should also indicate if a particular TSO-C129( ) GNSS installation meets the AC 20-138( ), Appendix 1 criteria for oceanic and remote continental operations.
G.7.4 Multisensor Systems. Multisensor systems integrating GNSS with FDE approved using the guidance in AC 20-138( ), Appendix 1 can be considered to meet RNP 10 requirements without time limitations.
G.7.5 GNSS Not Integrated with Other Sensors. AC 20-138( ) provides an acceptable means of complying with installation requirements for aircraft using a GPS that is not integrated with other sensors.
G.7.6 FDE Availability. The maximum allowable time for which FDE capability is projected to be unavailable is 34 minutes. The maximum outage time should be included as a condition of the RNP 10 approval.
Note: If predictions indicate that the maximum FDE outage time for the intended RNP 10 operation cannot be met, then the operation must be rescheduled when FDE is available or select another route where predicted FDE capability is available.
G.8 Single INS/IRU and a Single GNSS. Aircraft equipped with a single INS or IRU and a single GNSS meet the RNP 10 requirements without time limitations.
G.8.1 INS or IRU Equipment. The INS or IRU equipment must meet the standards of paragraph G.5 except that only one INS/IRU is required.
Appendix G G-7 G.8.2 GNSS Equipment. GNSS equipment must meet the standards of paragraph G.7, except that only one GNSS is required.
Note: If a GNSS FDE prediction indicates FDE unavailability exceeding 34 minutes, the performance criteria for the intended RNP 10 operation cannot be met using GNSS. The operator must predicate their RNP 10 operations on an INS/IRU for that portion of the flight.
G.9 Single INS/IRU or a Single GNSS. Aircraft equipped with a single INS/IRU or a single GNSS are approved for oceanic and remote continental navigation RNP 10 in the Houston oceanic Control Area/Flight Information Region (CTA/FIR), the GOMEX portion of the Miami Oceanic CTA/FIR, the Monterrey CTA, and Merida High CTA within the Mexico FIR/upper control area (UTA). Aircraft equipped with GNSS meet the RNP 10 requirements without time limitations.
Note: This approval is predicated on the air traffic surveillance provided in the GOMEX. Therefore, RNP 10 authorizations approved in accordance with this paragraph must clearly state that RNP 10 operational approval is limited to the GOMEX.
G.9.1 INS or IRU Equipment. INS or IRU equipment must meet the standards of paragraph G.5, except that only one INS/IRU is required.
G.9.2 GNSS Equipment. GNSS equipment must meet the standards of paragraph G.7, except that only one GNSS is required.
G.10 Operational Approval For RNP 10 Operations.
G.10.1 Aircraft Qualification Documentation. The aircraft or avionics manufacturers should develop aircraft qualification documentation that shows compliance with the applicable criteria, as appropriate for aircraft without approval to fly RNP 10 operations.
G.10.1.1 Prior to application, operators and manufacturers of their equipment should review all performance requirements. Installation of equipment by itself does not guarantee operational approval or permit operational use.
G.11 Operational Considerations.
G.11.1 Pilot Training and Qualification. Operators should ensure pilots are trained and qualified to operate in RNP 10 airspace.
G.11.2 Preflight. The following actions should be completed during preflight:
1. Review maintenance logs and forms to ascertain the condition of equipment required for flight in RNP 10 airspace or on an RNP 10 route, and
2. Ensure that maintenance action has been taken to correct defects to required equipment.
Appendix G G-8 G.11.2.1 During flight planning, the pilot should pay particular attention to conditions affecting the performance requirements for operations in RNP 10 airspace (or on RNP 10 routes), including:
1. Inertial system performance time limitations (if applicable),
2. GNSS FDE availability (if applicable), and Note: For GNSS systems, the maximum allowable predicted time for a loss of GNSS FDE capability must be 34 minutes or less.
3. Accounting for any operating restriction related to RNP 10 approval, if required for a specific navigation system.
G.11.3 General In-Flight Considerations.
G.11.3.1 For flexible route structures, manual entry of waypoints (i.e., latitude and longitude), may be permitted provided the potential for entry error by pilots is mitigated by adequate flightcrew procedures. The manual entry or creation of new waypoints, by manual entry of latitude and longitude or rho/theta values for fixed, published routes is not permitted. The pilot may modify the route through the insertion or deletion of specific waypoints in response to air traffic control (ATC) clearances. Pilots must not change any database waypoint type from a flyby to a flyover or vice versa.
G.11.3.2 The pilot must confirm the correct route is loaded. This process includes confirmation of the waypoint sequence, reasonableness of track angles and distances, and any other parameters that can be altered by the pilot, such as altitude or speed constraints. A navigation system textual display or navigation map display must be used.
G.11.3.3 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.
G.11.3.4 For RNP 10 operations, pilots must use a lateral deviation indicator, FD, or AP in lateral navigation (LNAV) mode. Pilots of aircraft with a lateral deviation display must ensure lateral deviation scaling is suitable for the RNP 10 operations.
G.11.3.5 Operator in-flight procedures must include verifying the RNP value set in the flight management system (FMS) matches the equipment capability and authorizations as annotated in the flight plan prior to entering oceanic and remote continental airspace.
G.11.3.6 All pilots are expected to maintain centerline, as depicted by onboard lateral deviation indicators and/or flight guidance during all RNP operations
Appendix G G-9 described in this AC unless authorized to deviate by ATC or under emergency conditions. For normal operations, XTK error/deviation (the difference between the displayed path and the displayed aircraft position relative to the displayed path, (i.e., FTE)) should be limited to half the RNP value associated with the procedure (i.e., 5 NM for RNP 10). Brief deviations from this standard (e.g., overshoots or undershoots) during and immediately after turns, up to a maximum of one times the RNP value (i.e., 10 NM for RNP 10), are allowable.
Note: Some aircraft do not display or compute a path during flyby turns. As such, pilots of these aircraft may not be able to adhere to half the lateral navigation accuracy during turns but are still expected to satisfy the standard during intercepts following turns and on straight segments. This does not apply to the execution of fixed radius transitions (FRT) procedures.
G.11.3.7 Operational qualification for RNP procedures requires flightcrew monitoring of lateral and, if installed, vertical deviations on the pilot’s primary flight displays (PFD) to ensure the aircraft remains within the bounds defined by the procedure. The deviation must be monitored, and action taken to minimize errors during all RNP operations.
G.11.3.8 If ATC issues a heading assignment taking the aircraft off a procedure, the pilot should not modify the primary flight plan in the RNP system until a clearance is received to rejoin the route or the controller confirms a new route clearance. The specified accuracy requirement does not apply when the aircraft is not on the published RNP 10 procedure.
G.11.3.9 The flightcrew must be able to assess the impact of equipment failure on the anticipated RNP operation and take appropriate action.
G.11.3.10 In addition to normal operating procedures, prior to commencing the procedure the flightcrew should accomplish the following:
1. For multisensor systems, crew must verify that the correct sensor is being used for position computation; and
2. Where Controller-Pilot Data Link Communication (CPDLC) is used to uplink flight plan changes for routing that is not contained in the navigation database, the flightcrew should confirm the RNP in effect matches the airspace requirement. If not, the flightcrew should manually enter the RNP applicable to the route.
G.11.3.11 Emergency procedures for operations in RNP 10 airspace or on RNP 10 routes are no different than normal oceanic emergency procedures with one exception, crews must be able to recognize and ATC must be advised when the aircraft is no longer able to navigate to its RNP 10 approved capability.
Appendix H H-1 APPENDIX H. ADVANCED REQUIRED NAVIGATION PERFORMANCE (A-RNP) H.1 Introduction.
H.1.1 Performance and Functional Requirements. This appendix provides guidance on the performance and functional requirements for the U.S. A-RNP operational implementation and related operations of:
• Required Navigation Performance (RNP) 2 (domestic or offshore en route),
• RNP 1 instrument departure procedures (DP),
• RNP 1 (RNP Obstacle Departure Procedures (ODP), and Standard Instrument Departures (SID)), and
• RNP 1 Standard Terminal Arrival Routes (STAR).
H.1.2 A-RNP Operations. A-RNP also applies to RNP approaches within the U.S. National Airspace System (NAS) where domestic air traffic control (ATC) procedures are applied.
Additionally, this appendix provides guidance for oceanic and remote continental Areas of Operation where RNP 2, RNP 4, or RNP 10 routes may apply.
Note: This appendix does not address all requirements that may be specified for particular operations. These requirements are specified in other documents, such as national operating rules, Aeronautical Information Publications (AIP), and the International Civil Aviation Organization (ICAO) Doc 7030, Regional Supplementary Procedures (SUPPS). Operators and pilots must adhere to the operational requirements of the appropriate state or regional authority before conducting flights outside of the U.S. NAS.
H.2 Applicable Operators. This appendix applies to all operators conducting A-RNP operations under Title 14 of the Code of Federal Regulations (14 CFR) parts 91, 91 subpart K (part 91K), 121, 125, 129, and 135 within the U.S. NAS or offshore airspace areas.
H.3 Application of A-RNP.
H.3.1 Navigation System Requirements. Navigation systems must have foundational RNP capability (Required Navigation Performance Approach (RNP APCH) to lateral navigation (LNAV), RNP 1, and RNP 2) as a prerequisite to implementing any A-RNP functions.
H.3.2 RNP Functions. Table H-1, RNP Functions, below lists RNP functions beginning with those that are required for the A-RNP qualification in the United States (Scalability, Radius to Fix (RF), and parallel offset). Fix radius transition (FRT) and Time of Arrival Control (TOAC) are optional capabilities that may be included in bundling authorizations discussed in Chapter 12, Bundling Concept, of this advisory circular (AC). Scalability is uniquely an A-RNP function and therefore described in detail in this appendix. The remaining RNP functions are described in Appendix I, Additional Capabilities. It is
Appendix H H-2 necessary to distinguish scalability from the other RNP functions because RF and parallel offset are not uniquely A-RNP functions and are used with other authorizations.
Those operators already qualified to perform RF and/or parallel offset are not required to be A-RNP qualified.
H.3.3 Requirement for A-RNP in the United States. The requirement for A-RNP in the United States is to be operationally and functionally capable of performing scalability, RF, and parallel offset.
H.3.4 Qualification. A-RNP qualification per AC 20-138( ), Airworthiness Approval of Positioning and Navigation Systems, means the aircraft navigation system performs all six A-RNP functions (RF legs, parallel offsets, Area Navigation (RNAV) holding, Scalable RNP, FRTs, and TOAC).
Note: Other States may choose to implement a different subset of functions, or all six functions for their advanced RNP definition.
Table H-1. RNP Functions RNP Function Reference Application Required/Optional Scalability H.5 Appendix A, See Table 5-1 Required for U.S.
Radius to Fix (RF)* I.2 Appendices: A, C, D Required for U.S.
Parallel Offset* I.3 Appendices: E, F Required for U.S.
Fixed Radius Transition (FRT) I.5 Currently not used in U.S. Optional Time of Arrival Control (TOAC) I.6 Currently not used in U.S. Optional Note 1: In addition to RNP functions, higher continuity may be required where specified.
Note 2: *Required for A-RNP in the United States.
H.3.5 Scalable Lateral Navigation. The requirement for scalable lateral navigation accuracy invoked in this AC (optional in the ICAO navigation specification (Nav Spec)) leverages existing aircraft equipage. This functionality, coupled with mandatory RF capability, supports the design of beneficial procedures, especially at locations with high-density traffic or challenging terrain. A-RNP allows for the bundling of approvals across flight phases, improving efficiencies during initial certification and operational use.
H.3.6 Design. A-RNP is designed for operation in oceanic/remote continental airspace, on the domestic or offshore en route structure as well as on arrival, approaches, and DPs.
H.3.7 Multiple Operational Approvals. An A-RNP aircraft qualification may be applied to multiple operational approvals without the need for re-examination of aircraft eligibility.
This enables an operator’s approved procedures, training, etc. to be common to multiple approvals. The A-RNP aircraft qualification will also facilitate multiple operations specifications (OpSpecs).
Appendix H H-3 H.3.8 Features and Requirements. For A-RNP, some features/requirements may be required in one flight phase and optional or unnecessary in another. No distinctions are made regarding flight phase association in providing a general set of criteria spanning all phases and navigation applications. Where such differences are deemed important or the operational need is for one application, a specific operational approval (e.g., RNP 1), is expected to be used instead.
H.3.9 Area Navigation Capability. The area navigation capability required for A-RNP will encompass the lateral aspects of the desired flightpath. The predictability and performance monitoring and alerting for the lateral flightpath will support a number of applications including closely-spaced procedures/routes and operations in terrain-challenged areas.
H.4 Aircraft and System Requirements for A-RNP.
H.4.1 RNP Capability. Navigation systems must have foundational RNP capability (RNP APCH to LNAV, RNP 1, and RNP 2) as a prerequisite to implementing any A-RNP functions.
Note: 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.
H.4.2 System Requirements. AC 20-138( ) defines the system requirements for A-RNP functions.
H.5 RNP Scalability.
H.5.1 Definition. RNP scalability refers to the ability of the RNP system to automatically retrieve and set the RNP value for each leg segment of a route or procedures from the onboard navigation database. When a change occurs to a smaller RNP value
(e.g., from RNP 1 to RNP 0.3), the change must be completed by the first fix defining the leg with the smaller RNP value requirement. The timing of this change must also consider any latency in alerting from the RNP system.
Note: When the RNP system cannot automatically set the RNP value for each leg segment, operational procedures necessary to manually set the RNP value must be identified.
H.5.2 Usage. Scalable RNP is intended for legs on RNP routes or procedures where ATC, terrain, and/or obstacle considerations provide a benefit on selected legs to using RNP values other than RNP 2 or RNP 1. RTCA/DO-236C, paragraph 3.2.6 provides equipment requirements for assigning an RNP value to a leg and transitions between legs (See Appendix A and Table 5-1).