U.S. D epartment of Transportation Federal Aviation Administration Advisory Circular Subject: U.S. Terminal and En Route Area Navigation (RNAV) Operations Date: 4/14/15 AC No: 90-100A Initiated by: AFS-400 Change: 2
1. PURPOSE. This advisory circular (AC) provides operational and airworthiness guidance for operation on U.S. Area Navigation (RNAV) routes, instrument departure procedures (DPs), and Standard Terminal Arrivals (STAR). Operators and pilots should use the guidance in this AC to determine their eligibility for these U.S. RNAV routes and procedures. In lieu of following this guidance without deviation, operators may elect to follow an alternative method, provided the alternative method is found to be acceptable by the Federal Aviation Administration (FAA). For the purpose of this AC, “compliance” means meeting operational and functional performance criteria. Mandatory terms in this AC such as “must” are used only to ensure applicability of these particular methods of compliance when the acceptable means of compliance described are used.
This AC does not change, add, or delete regulatory requirements or authorize deviations from regulatory requirements.
2. PRINCIPAL CHANGES. This change updates the RAIM Web site information to direct all users of www.raimprediction.net to now use the Service Availability Prediction Tool (SAPT) Web site.
PAGE CONTROL CHART Remove Pages Dated Insert Pages Dated Page 11 3/1/07 Page 11 4/14/15 ORIGINAL SIGNED by /s/ John Barbagallo Deputy Director, Flight Standards Service
U.S.
Department of Transportation Federal Aviation Administration Advisory Circular Subject: U.S. Terminal and En Route Area Navigation (RNAV) Operations Date: 3/1/07 AC No: 90-100A Initiated by: AFS-400 Change:
1. PURPOSE.
a. This advisory circular (AC) provides operational and airworthiness guidance for operation on U.S. Area Navigation (RNAV) routes, instrument departure procedures (DP), and Standard Terminal Arrivals (STAR). Operators and pilots should use the guidance in this AC to determine their eligibility for these U.S. RNAV routes and procedures. In lieu of following this guidance without deviation, operators may elect to follow an alternative method, provided the alternative method is found to be acceptable by the Federal Aviation Administration (FAA). For the purpose of this AC, “compliance” means meeting operational and functional performance criteria. Mandatory terms in this AC such as “must” are used only to ensure applicability of these particular methods of compliance when the acceptable means of compliance described are used.
This AC does not change, add, or delete regulatory requirements or authorize deviations from regulatory requirements. The contents of this document do not have the force and effect of law and are not meant to bind the public in any way. This document is intended only to provide clarity to the public regarding existing requirements under the law or agency policies.
NOTE: New applicants for a type certificate (TC) or Supplemental Type Certificate (STC) should include a statement of compliance to this AC and qualification for U.S. RNAV routes and terminal procedures when the aircraft is found in compliance with this AC.
b. Applicability of AC 90-100A. AC 90-100A applies to operation on U.S. RNAV routes (Q-routes and T-routes), DPs (Obstacle DPs (ODP) and Standard Instrument Departures (SID)), and STARs. It does not apply to over water RNAV routes (refer to Title 14 of the Code of Federal Regulations (14 CFR) part 91, § 91.511, including the Q-routes in the Gulf of Mexico and the Atlantic routes) or Alaska very high frequency omni-directional range (VOR)/distance measuring equipment (DME) RNAV routes (“JxxxR”). It does not apply to off-route RNAV operations, Alaska Global Positioning System (GPS) routes or Caribbean routes, or helicopter operations involving offshore or specific heliport procedures.
c. Perf ormance-Based Navigation Concept. This AC sets out a series of performance and functional criteria necessary to conduct RNAV procedures.
d. Background. This criterion is consistent with the International Civil Aviation Organization (ICAO) guidance material for the implementation of area navigation (RNAV 1 and RNAV 2) operations. AC 90-100 became effective 7 January 2005. Since then, ICAO has continued to harmonize RNAV performance criteria. AC 90-100A reflects these harmonized
Page 2 Par 1 ICAO performance-based navigation criteria as well as lessons learned from the initial U.S.
RNAV implementation.
e. Structure. After the initial paragraphs which include Terminology and References, this AC is structured as follows:
• General Information (paragraph 6).
• RNAV System Eligibility (paragraph 7).
• RNAV System Approval Process (paragraph 8).
• Operator Approval Process (paragraph 9).
• U.S. RNAV Flightcrew Operating Procedures (paragraph 10).
• Pilot Knowledge Requirements and Training (paragraph 11).
• Criteria for Approval of Baseline Area Navigation (RNAV) Systems Using Distance Measuring Equipment (DME) (Appendix 1).
• Criteria for Approval of Baseline Area Navigation (RNAV) Systems Using Distance Measuring Equipment (DME) and Inertial Reference Unit (IRU) (Appendix 2).
• Navigation Displays and Functions (Appendix 3).
2. CANCELLATION. AC 90-100, U.S. Terminal and En Route Area Navigation (RNAV) Operations, dated January 7, 2005, is canceled.
3. RELATED CODE OF FEDERAL REGULATIONS SECTIONS. Title 14 CFR part 91, §§ 91.123 and 91.205; part 95; part 121, § 121.349; part 125, § 125.203; part 129, § 129.17; and part 135, § 135.165.
4. TERMINOLOGY. For the purpose of operations on RNAV routes and procedures, the following definitions are provided:
a. Aircraft-Based Augmentation System (ABAS). A system augmenting and/or integrating information obtained from other Global Navigation Satellite System (GNSS) elements with information on board the aircraft. The most common form of ABAS is receiver autonomous integrity monitoring (RAIM).
b. Area Navigation (RNAV). A method of navigation which permits aircraft operation on any desired flight path within the coverage of station-referenced navigation aids or within the limits of the capability of self-contained aids, or a combination of these. For the purposes of this AC, the specified RNAV accuracy must be met 95 percent of the flight time.
(1) RNAV 1 requires a total system error of not more than 1 nautical mile (NM) for 95 percent of the total flight time.
(2) RNAV 2 requires a total system error of not more than 2 NM for 95 percent of the total flight time.
c. Area Navigation (RNAV) System. This AC only addresses RNAV systems using positioning inputs from GPS/GNSS and DME, and Inertial Reference Units (IRU). Criteria for
Par 4 Page 3 RNAV systems are discussed in Appendix 1 and 2. Criteria for RNAV system functionality is discussed in Appendix 3.
d. Critical Distance Measuring Equipment (DME). A DME facility that, when unavailable, results in navigation service which is insufficient for DME/DME/IRU supported operations along a specific route or procedure. The required performance assumes an aircraft’s RNAV system meets the minimum standard (baseline) for DME/DME RNAV systems found in Appendix 1, or the minimum standard for DME/DME/IRU systems found in Appendix 2. For example, terminal RNAV DPs and STARs may be published with only two DMEs, in which case, both are critical.
e. DME/DME (D/D) RNAV. Refers to navigation using DME ranging from at least two DME facilities to determine position.
f. DME/DME/Inertial (D/D/I) RNAV. Refers to navigation using DME ranging from at least two DME facilities to determine position along with use of an IRU to provide sufficient position information during limited DME gaps.
g. Flight Technical Error (FTE). Accuracy with which an aircraft is controlled, as measured by the indicated aircraft position with respect to the indicated command or desired position. It does not include procedural blunder errors.
h. Global Navigation Satellite System (GNSS). The GNSS is a worldwide position and time determination system, which includes one or more satellite constellations, aircraft receivers, and system integrity monitoring. GNSS is augmented as necessary to support the Required Navigation Performance (RNP) for the actual phase of operation.
i. Global Positioning System (GPS). The U.S. GNSS core satellite constellation providing space-based positioning, velocity, and time. GPS is composed of space, control, and user elements.
j. Position Estimation Error (PEE). Difference between true position and estimated position.
k. Receiver Autonomous Integrity Monitoring (RAIM). A technique used within a GPS receiver/processor to monitor GPS signal performance. This integrity determination is achieved by a consistency check among redundant measurements.
l. RNAV Procedure. An RNAV instrument DP or RNAV STAR.
(1) Instrument Departure Procedure (DP). A DP is a published instrument flight rules (IFR) procedure providing obstruction clearance from the terminal area to the en route structure.
There are two types of DPs: SIDs and ODPs.
(a) Standard Instrument Departure (SID). A SID is a published IFR air traffic control (ATC) DP providing obstacle clearance and a transition from the terminal area to the en route structure. SIDs are primarily designed for air traffic system enhancement to expedite traffic flow and to reduce pilot/controller workload.
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(b) Obstacle Departure Procedure (ODP). A preplanned IFR DP printed for pilot use in textual or graphic form to provide obstruction clearance via the least onerous route from the terminal area to the appropriate en route structure. ODPs are recommended for obstruction clearance and may be flown without ATC clearance unless an alternate DP (SID or radar vector) has been specifically assigned by ATC.
(2) Standard Terminal Arrival (STAR). A STAR is a published IFR ATC arrival procedure that provides a transition from the en route structure to the terminal area. STARs may include one or more runway transitions providing guidance to either a standard instrument approach procedure or a point in space from which radar vectors are provided by ATC.
m. RNAV Route. An RNAV route (“Q” or “T”), within the high or low altitude structure of the contiguous United States, requiring system performance by GPS/GNSS or DME/DME/IRU RNAV systems, as required.
n. Total System Error. The difference between the true position and the desired position.
This error is equal to the vector sum of the path steering error, path definition error, and PEE.
5. REFERENCES (current editions).
a. Technical Standard Order (TSO)-C66, Distance Measuring Equipment (DME) Operating within the Radio Frequency Range of 960-1215 Megahertz.
b. TSO-C115, Airborne Area Navigation Equipment Using Multi-Sensor Inputs.
c. TSO-C129, Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS).
d. TSO-C145, Airborne Navigation Sensors Using the Global Positioning System Augmented by the Satellite Based Augmentation System (SBAS).
e. TSO-C146, Stand-Alone Airborne Navigation Equipment Using the Global Positioning System Augmented by Satellite Based Augmentation System (SBAS).
f. AC 20-138, Airworthiness Approval of Airworthiness Approval of Positioning and Navigation Systems.
g. AC 20-153, Acceptance of Aeronautical Data Processes and Associated Databases.
h. AC 25-15, Approval of Flight Management Systems in Transport Category Airplanes.
i. AC 90-96, Approval of U.S. Operators and Aircraft to Operate Under Instrument Flight Rules (IFR) in European Airspace Designated for Basic Area Navigation (B-RNAV)/RNAV 5 and Precision Area Navigation (P-RNAV).
j. AC 90-105, Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System and in Oceanic and Remote Continental Airspace;
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k. FAA Order JO 7470.1, Distance Measuring Equipment (DME)/DME Infrastructure Evaluation for Area Navigation (RNAV) Routes and Procedures.
l. Joint Aviation Authority (JAA) TGL-10, Airworthiness and Operational Approval for Precision RNAV Operations in Designated European Airspace, and the corresponding JAA TGL-10 Frequently Asked Questions (FAQ) Document.
m. RTCA/DO-187, Minimum Operational Performance Standards for Airborne Area Navigation Equipment Using Multi-Sensor Inputs.
n. RTCA/DO-189, Minimum Performance Standard for Airborne Distance Measuring Equipment (DME) Operating Within the Radio Frequency Range of 960-1215 MHz.
o. RTCA/DO-200, Standards for Processing Aeronautical Data.
p. RTCA/DO-201, User Requirements for Navigation Data.
q. RTCA/DO-236, Minimum Aviation System Performance Standards: Required Navigation Performance for Area Navigation.
r. RTCA/DO-283, Minimum Operational Performance Standards for Required Navigation Performance for Area Navigation.
6. GENERAL INFORMATION ON RNAV 1 AND RNAV 2 OPERATIONS.
a. Operation on U.S. RNAV routes, DPs, and STARs:
(1) Relies on normal descent profiles and identifies minimum segment altitude requirements;
NOTE: Pilots operating aircraft with an approved barometric vertical navigation (baro-VNAV) system may continue to use their baro-VNAV system while executing U.S. RNAV routes, DPs, and STARs. Operators must ensure compliance with all altitude constraints as published in the procedure by reference to the barometric altimeter.
(2) Does not require the pilot to monitor ground-based Navigational Aids (NAVAID) used in position updating unless required by the Airplane Flight Manual (AFM), pilot’s operating handbook (POH), or the operating manual for their avionics;
(3) Bases obstacle clearance assessments on the associated required system performance;
and
(4) Guidance in this AC does not supersede appropriate operating requirements for equipage. For example, part 91 can have a single RNAV system, and part 121 can have a single RNAV system and another independent navigation system allowing safe flight to a suitable alternate airport.
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b. The DME navigation infrastructure supporting the design of an RNAV route or procedure has been assessed and validated by the FAA. This includes analysis by FAA flight inspection assets. DME coverage may use Expanded Service Volume (ESV) for select DME facilities so there is no requirement to use VOR, Localizer (LOC), Non-Directional Beacon (NDB), or Attitude and Heading Reference System (AHRS) during normal operation of the DME/DME RNAV system. ESV facilities require a satisfactory flight inspection prior to use.
(1) DME signals are considered to meet signal-in-space accuracy tolerances everywhere the signals are received.
(2) For RNAV operations where reliance is placed upon the IRU, some aircraft systems temporarily revert to VOR/DME-based navigation before reverting to inertial coasting. When the VOR is within 40 NM from the route/procedure and there is insufficient DME/DME navigation infrastructure, the impact of VOR radial accuracy has been evaluated by the FAA and determined to not affect aircraft position accuracy.
(3) The available navigation infrastructure supporting the procedure will be clearly designated on all appropriate charts (for example, GPS or DME/DME/IRU).
(4) The FAA will monitor the navigation infrastructure and issue timely warnings of outages (Notice to Airmen (NOTAM)).
(5) The navigation standard (for example, RNAV 1 or RNAV 2) required for all RNAV procedures/routes will be clearly designated on all appropriate charts. However, SIDs, ODPs, and STARs will be flown with RNAV 1 procedures.
(6) All routes and procedures referenced in this AC are intended to be flown by DME/DME/IRU and/or GPS/GNSS equipped aircraft meeting the performance requirements in this AC.
c. If any critical DME facilities exist, they are identified within the relevant U.S. Flight Information Publications (FLIP).
d. Unless the RNAV route, DP, or STAR specifically requires GPS or GNSS equipage, aircraft on the RNAV route, DP, or STAR must be within ATC radar surveillance and communication.
e. All DME ground stations maintained by the FAA and used to define the availability of these RNAV routes, DPs, and STARs comply with applicable ICAO standards.
f. All routes/procedures must be based upon the World Geodetic System 1984 (WGS 84) coordinates.
g. The navigation data published for the routes, procedures and supporting navigation aids must meet the requirements of ICAO Annex 15.
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7. RNAV SYSTEM ELIGIBILITY.
a. Aircraft with a statement of compliance to this AC in their AFM, POH, or the operating manual for their avionics meet the performance and functional requirements of this AC.
b. Aircraft with Precision RNAV (P-RNAV) approval based on GNSS capability meet the functional requirements of this AC. Due to differences in radio navigation infrastructure in the United States, if the approval is based on DME/DME or DME/DME/IRU, the operator should ensure the equipment meets the criteria in Appendix 1 or 2, as applicable.
c. The following systems meet many of the requirements defined in this AC. Such equipment still requires evaluation by the manufacturer against all the functional and performance requirements in this AC. The RAIM prediction program should comply with the criteria in AC 20-138, chapter 5.
(1) Aircraft with TSO-C129/C129a sensor (Class B or C) and the requirements in a TSO-C115b Flight Management System (FMS), installed for IFR use in accordance with (IAW) AC 20-138.
(2) Aircraft with TSO-C145a sensor, and the requirements in a TSO-C115b FMS, installed for IFR use IAW AC 20-138.
(3) Aircraft with TSO-C129/C129a Class A1 (without deviating from the functionality described in Appendix 3 of this document) installed for IFR use IAW AC 20-138.
(4) Aircraft with TSO-C146 (without deviating from the functionality described in Appendix 3 of this document) installed for IFR use IAW AC 20-138.
NOTE: Refer to paragraph 5 for TSO and AC references.
d. Aircraft with a statement from the manufacturer documenting compliance with the criteria in this AC (Appendix 1 or 2, as applicable, and Appendix 3) meet the performance and functional requirements of this AC. These statements should include the airworthiness basis for compliance. Compliance with the sensor requirements in paragraph 8 will have to be determined by the equipment or aircraft manufacturer, while compliance with the functional requirements in Appendix 3 may be determined by the manufacturer or by inspection by the operator.
NOTE 1: Aircraft with a demonstrated RNP capability will annunciate when no longer satisfying the performance requirement associated with the operation. However, for DME/DME/IRU-based procedures, the manufacturer still has to determine compliance with Appendix 1 or 2 to support evaluation of the DME infrastructure.
NOTE 2: Aircraft with a TSO-C129 GPS sensor and a TSO-C115 or C115a FMS may not meet all of the requirements defined in this AC. Such equipment would require further evaluation by the manufacturer against all the functional and performance requirements in this AC.
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8. RNAV SYSTEM APPROVAL PROCESS.
a. Navigation System Accuracy. The navigation system accuracy is dependent on the total system error, defined in paragraph 4 of this AC.
(1) RNAV Routes. Aircraft operating on RNAV routes must maintain a total system error bounded by the RNAV value for 95 percent of the total flight time. A Flight Technical Error (FTE) of 1.0 NM (95 percent) is acceptable for RNAV 2 operations. RNAV 2 will be used for en route unless otherwise specified.
(2) RNAV 1 DPs and STARs. Aircraft operating on RNAV 1 DPs and STARs must maintain a total system error of not more than 1 NM for 95 percent of the total flight time. An FTE of 0.5 NM (95 percent) is acceptable for RNAV 1 operations. RNAV 1 will appear on all RNAV SID and STAR charts.
b. Navigation Sensors. U.S. RNAV operations are based upon the use of RNAV equipment that automatically determines aircraft position in the horizontal plane using inputs from the following types of positioning sensors (no specific priority).
(1) GNSS in accordance with TSO-C145a, TSO-C146a, and TSO-C129/C129a.
Positioning data from other types of navigation sensors may be integrated with the GNSS data provided it does not cause position errors exceeding the total system error requirements. The use of GPS equipment approved to TSO-C129 is limited to those which include the minimum system functions specified in Appendix 3. As a minimum, integrity should be provided by ABAS. In addition, GPS standalone equipment should include the following additional functions:
• Pseudorange step detection, and
• Health word checking.
For procedures requiring GPS and/or aircraft approvals requiring GPS, if the navigation system does not automatically alert the flightcrew of a loss of GPS, the operator must develop procedures to verify correct GPS operation.
(2) DME/DME RNAV equipment complying with the criteria in Appendix 1. Based on current DME availability evaluations, coverage is not sufficient to support DME/DME RNAV operations without additional IRU augmentation or using GPS.
(3) DME/DME/IRU RNAV equipment complying with the criteria in Appendix 2.
NOTE: Long-range navigation-C system (LORAN-C) criteria have not been developed.
c. Functional Criteria Listed in Appendix 3. The requirements of Appendix 3 help ensure aircraft RNAV system performance meets procedure design criteria.
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9. OPERATOR APPROVAL PROCESS.
a. Background. This section identifies the operational requirements for RNAV 2 and RNAV 1 operations. Performance requirements must be met. However, the approval process depends on the operating rules for the particular operation (e.g., part 91 versus part 121).
b. After Completing the Following Steps. An RNAV operational approval or appropriate operations specifications/management specifications (OpSpecs/MSpecs), should then be issued by the FAA before conducting RNAV operations. Part 91 operators (excluding subpart K) meeting the RNAV performance requirements in this AC should follow the aircraft and training guidance in this AC, but are not required to obtain a Letter of Authorization (LOA).
(1) Aircraft equipment eligibility must be determined and documented;
(2) Operating procedures for the navigation systems to be used and the operator navigation database process must be documented;
(3) Flightcrew training based upon the operating procedures must be documented;
(4) The above material must be accepted by the FAA; and
(5) Operational approval should then be obtained IAW operating rules.
c. Documentation for Conducting RNAV Operations.
(1) Aircraft Eligibility.
(a) Description of aircraft equipment. The operator must have a configuration list detailing pertinent components and equipment to be used for RNAV 2/RNAV 1.
(b) Eligibility airworthiness documents. Relevant documentation acceptable to the FAA must be available to establish that the aircraft is equipped with RNAV systems meeting RNAV 2/RNAV 1 requirements. Manufacturers evaluate their systems against these criteria, and a current list of compliant equipment can be found at the Flight Technologies and Procedures Division website (applicable to all operators) https://www.faa.gov/about/office_org/headquarter s_offices/avs/offices/afx/afs/afs400/afs410/pbn/. Pilots and operators can confirm the capability of their equipment on this list, or obtain equipment performance information from the relevant aircraft and avionics manufacturer.
(2) Training Documentation.
(a) Parts 91K, 121, 125, 129, and 135 operators should have a training program addressing the operational practices, procedures and training items identified in paragraph 11 of this AC (e.g., initial, upgrade or recurrent training for flightcrew, dispatchers or maintenance personnel).
Page 10 Par 9 NOTE: It is not required to establish a separate training program or regimen if RNAV training in paragraph 11 is already an integrated element of a training program.
(b) Part 91 operators should be familiar with the practices and procedures identified in paragraph 11, Pilot Knowledge Requirements and Training.
(3) Operations Manuals and Checklists.
(a) Operations manuals and checklists for commercial operators must address information/guidance on the standard operating procedures detailed in paragraph 10 of this AC.
The appropriate manuals should contain navigation operating instructions and contingency procedures where specified. Manuals and checklists must be submitted for review as part of the application process.
(b) Private operators should operate using the practices and procedures identified in paragraph 11, Pilot Knowledge Requirements and Training.
(4) Maintenance Considerations.
(a) Any minimum equipment list (MEL) revisions necessary to address RNAV provisions must be approved.
(b) If an RNAV operational approval is granted on the basis of a specific operational procedure, operators must modify the MEL, or equivalent, and specify the required dispatch conditions.
NOTE: Since this may constitute a special operation, it is not intended to require MEL requirements for each aspect of RNAV operations.
(c) Parts 91K, 121, 125, 129, and 135 operators should have an approved maintenance program.
10. U.S. RNAV FLIGHTCREW OPERATING PROCEDURES. Pilots should be familiar with the normal operating and contingency procedures associated with U.S. RNAV routes, DPs, and STARs.
a. Preflight Planning.
(1) Operators and pilots intending to conduct operations on U.S. RNAV routes, DPs, and STARs are expected to file the appropriate flight plan suffix code as designated in the current Aeronautical Information Manual (AIM) and other FLIP.
(2) NOTAMs should be checked to verify the health of critical DMEs for navigation relying on DME. Pilots should assess their capability to navigate (potentially to an alternate destination) in case of failure of critical DME while airborne.
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(3) The onboard navigation data must be current and appropriate for the region of intended operation and must include the navigation aids, waypoints, and relevant coded terminal airspace procedures for the departure, arrival, and alternate airfields. RNAV STAR procedures may be designed using multiple runway transitions. Operators not having this functionality shall provide an acceptable alternative means (for example, a tailored navigation data base). If no equivalent means are available to fly the charted RNAV procedure containing multiple runway transitions, operators will not file or accept clearance for these procedures.
NOTE: Navigation databases are expected to be current for the duration of the flight. If the Aeronautical Information Regulation and Control (AIRAC) cycle will 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.
Traditionally, this has been accomplished by verifying electronic data against paper products. One acceptable means is to compare aeronautical charts (new and old) to verify navigation fixes prior to dispatch. If an amended chart affecting navigation data is published for the procedure, the database must not be used to conduct the procedure.
(4) If not equipped with GPS/GNSS, aircraft must be capable of navigation system updating using DME/DME/IRU for RNAV 2 or RNAV 1 routes, as well as RNAV 1 DPs and STARs. As stated in subparagraph 8b(1), if the navigation system does not automatically alert the flightcrew of a loss of GPS/GNSS, the operator must develop procedures to verify correct GPS/GNSS operation.
(5) If TSO-C129 equipment is used to solely satisfy the RNAV requirement, GPS RAIM availability must be confirmed for the intended route of flight (route and time) using current GPS satellite information. The availability of Satellite-based Augmentation System (SBAS) or ABAS fault detection can be determined through NOTAMs (if available) or through prediction for the intended RNAV 1 or RNAV 2 operation. Operators may choose to monitor the status of each satellite in its plane/slot position, account for the latest GPS constellation NOTAMs, and compute RAIM availability using model-specific RAIM prediction software, or by using the Service Availability Prediction Tool (SAPT) on the FAA en route and terminal RAIM prediction website, or by contacting a Flight Service Station (FSS). Receiver RAIM prediction capability can also be used. In the event of a predicted, continuous loss of RAIM of more than 5 minutes for any part of the intended flight, the flight should be delayed, canceled, or rerouted where RAIM requirements can be met. Pilots should assess their capability to navigate (potentially to an alternate destination) in case of failure of GPS navigation.
(6) If TSO-C145/C146 equipment is used to satisfy the RNAV requirement, the pilot/operator need not perform the prediction if wide area augmentation system (WAAS) coverage is confirmed to be available along the entire route of flight.
NOTE: Outside the U.S. or in areas where WAAS coverage is not available, operators using TSO-C145/C146 receivers are required to check GPS RAIM availability.