AIM ¶ 5-1-16 — RNAV and RNP Operations
AIM 5-1-16 explains preflight planning for RNAV/RNP ops: RAIM prediction, database currency, OROCA terrain clearance, and system verification for pilots.
In Plain English
AIM 5-1-16 is your preflight checklist for RNAV/RNP operations. Before flying, you must confirm both the navigation infrastructure (ground-based aids and GPS) and your onboard equipment are available for the entire route and time of flight.
Key responsibilities:
- Terrain clearance: On unpublished RNAV departures into uncontrolled airspace (composite VFR/IFR or IFR clearance), the PIC is responsible for terrain/obstruction clearance until reaching the MEA/MIA/MVA/OROCA.
- OROCA provides 1,000 ft clearance (2,000 ft in mountainous areas) but is not assessed for NAVAID, ATC surveillance, or comm coverage — it's for situational awareness and contingency use only.
- Navigation database must be current and include departure, arrival, and alternate procedures. Don't use a procedure if database validity is in doubt.
- System initialization: Verify database currency and correct aircraft position. Crosscheck cleared flight plan against charts — waypoint sequence, track angles, distances, altitude/speed constraints, and fly-by vs. fly-over waypoints.
- Before takeoff: Verify RNAV system operation and correct airport/runway loaded.
- RAIM prediction is required if using TSO-C129() equipment. If a continuous RAIM outage of more than 5 minutes is predicted, delay, cancel, or reroute.
- WAAS exception: TSO-C145/C146 equipment with confirmed WAAS coverage doesn't require RAIM prediction within the U.S.
If the required RNP level cannot be achieved, revise the route or delay the flight.
AIM Source Text
FAA AIM ¶ 5-1-165-1-16. 5-1-16. RNAV and RNP Operations
During the pre-flight planning phase the availability of the navigation infrastructure required for the intended operation, including any non-RNAV contingencies, must be confirmed for the period of intended operation. Availability of the onboard navigation equipment necessary for the route to be flown must be confirmed. Pilots are reminded that on composite VFR to IFR flight plan, or on an IFR clearance, while flying unpublished departures via RNAV into uncontrolled airspace, the PIC is responsible for terrain and obstruction clearance until reaching the MEA/MIA/MVA/OROCA. NOTE- OROCA is a published altitude which provides 1,000 feet of terrain and obstruction clearance in the U.S. (2,000 feet of clearance in designated mountainous areas). These altitudes are not assessed for NAVAID signal coverage, air traffic control surveillance, or communications coverage, and are published for general situational awareness, flight planning and in-flight contingency use. If a pilot determines a specified RNP level cannot be achieved, revise the route or delay the operation until appropriate RNP level can be ensured. The onboard navigation database must be current and appropriate for the region of intended operation and must include the navigation aids, waypoints, and coded terminal airspace procedures for the departure, arrival and alternate airfields. During system initialization, pilots of aircraft equipped with a Flight Management System or other RNAV-certified system, must confirm that the navigation database is current, and verify that the aircraft position has been entered correctly. Flight crews should crosscheck the cleared flight plan against charts or other applicable resources, as well as the navigation system textual display and the aircraft map display. This process includes confirmation of the waypoints sequence, reasonableness of track angles and distances, any altitude or speed constraints, and identification of fly-by or fly-over waypoints. A procedure must not be used if validity of the navigation database is in doubt. Prior to commencing takeoff, the flight crew must verify that the RNAV system is operating correctly and the correct airport and runway data have been loaded. During the pre-flight planning phase RAIM prediction must be performed if TSO-C129() equipment is used to solely satisfy the RNAV and RNP requirement. GPS RAIM availability must be confirmed for the intended route of flight (route and time) using current GPS satellite information. In the event of a predicted, continuous loss of RAIM of more than five (5) minutes for any part of the intended flight, the flight should be delayed, canceled, or re-routed where RAIM requirements can be met. Operators may satisfy the predictive RAIM requirement through any one of the following methods: Operators may monitor the status of each satellite in its plane/slot position, by accounting for the latest GPS constellation status (for example, NOTAMs or NANUs), and compute RAIM availability using model-specific RAIM prediction software; Operators may use the Service Availability Prediction Tool (SAPT) on the FAA en route and terminal RAIM prediction website; Operators may contact a Flight Service Station to obtain non-precision approach RAIM; Operators may use a third party interface, incorporating FAA/VOLPE RAIM prediction data without altering performance values, to predict RAIM outages for the aircraft's predicted flight path and times; Operators may use the receiver's installed RAIM prediction capability (for TSO-C129a/Class A1/B1/C1 equipment) to provide non-precision approach RAIM, accounting for the latest GPS constellation status (for example, NOTAMs or NANUs). Receiver non-precision approach RAIM should be checked at airports spaced at intervals not to exceed 60 NM along the RNAV 1 procedure's flight track. “Terminal” or “Approach” RAIM must be available at the ETA over each airport checked; or, Operators not using model-specific software or FAA/VOLPE RAIM data will need FAA operational approval. NOTE- If TSO-C145/C146 equipment is used to satisfy the RNAV and RNP requirement, the pilot/operator need not perform the prediction if WAAS coverage is confirmed to be available along the entire route of flight. 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.
Oral Exam Questions a DPE Might Ask
Q1Who is responsible for terrain and obstruction clearance on an unpublished RNAV departure into uncontrolled airspace?
Per AIM 5-1-16, the PIC is responsible for terrain and obstruction clearance until reaching the MEA, MIA, MVA, or OROCA — even on a composite VFR/IFR flight plan or IFR clearance.
Q2What is OROCA and what clearance does it provide?
Per AIM 5-1-16, OROCA is a published altitude providing 1,000 ft of terrain/obstruction clearance (2,000 ft in designated mountainous areas). It is not assessed for NAVAID signal, ATC surveillance, or communications coverage and is intended for situational awareness, flight planning, and in-flight contingency use.
Q3When is a RAIM prediction required during preflight planning, and what triggers a delay or reroute?
Per AIM 5-1-16, RAIM prediction must be performed if TSO-C129() equipment is used to solely satisfy the RNAV/RNP requirement. If a predicted continuous loss of RAIM exceeds 5 minutes for any part of the flight, the flight should be delayed, canceled, or rerouted. TSO-C145/C146 (WAAS) equipment is exempt when WAAS coverage is confirmed along the entire route within the U.S.
Related Paragraphs in AIM Chapter 5