4-6-8 Pilot/Controller Phraseology
AIM Chapter 4. Air Traffic Control — Section 4-6, Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in the Domestic U.S., Alaska, Offshore Airspace and the San Juan FIR
Official text — AIM 4-6-8
AIM — FAA OPERATIONAL GUIDANCETBL 4-6-1 shows standard phraseology that pilots and controllers will use to communicate in DRVSM operations.
Message | Phraseology
For a controller to ascertain the RVSM approval status of an aircraft: | (call sign) confirm RVSM approved
Pilot indication that flight is RVSM approved | Affirm RVSM
Pilot report of lack of RVSM approval (non-RVSM status). Pilot will report non-RVSM status, as follows: | Negative RVSM, (supplementary information, e.g., “Certification flight”).
On the initial call on any frequency in the RVSM airspace and . . .. b. In all requests for flight level changes pertaining to flight levels within the RVSM airspace and . . .. c. In all read backs to flight level clearances pertaining to flight levels within the RVSM airspace and . . .. d. In read back of flight level clearances involving climb and descent through RVSM airspace (FL 290 - 410).
NOTE- Pilot report of one of the following after entry into RVSM airspace: all primary altimeters, automatic altitude control systems or altitude alerters have failed. (See paragraph 4-6-9 , Contingency Actions: Weather Encounters and Aircraft System Failures that Occur After Entry into RVSM Airspace.) This phrase is to be used to convey both the initial indication of RVSM aircraft system failure and on initial contact on all frequencies in RVSM airspace until the problem ceases to exist or the aircraft has exited RVSM airspace. | Unable RVSM Due Equipment
ATC denial of clearance into RVSM airspace | Unable issue clearance into RVSM airspace, maintain FL
*Pilot reporting inability to maintain cleared flight level due to weather encounter. (See paragraph 4-6-9 , Contingency Actions: Weather Encounters and Aircraft System Failures that Occur After Entry into RVSM Airspace.). | *Unable RVSM due (state reason) (e.g., turbulence, mountain wave)
ATC requesting pilot to confirm that an aircraft has regained RVSM-approved status or a pilot is ready to resume RVSM | Confirm able to resume RVSM
Pilot ready to resume RVSM after aircraft system or weather contingency | Ready to resume RVSM
Reproduced from the FAA Aeronautical Information Manual (Basic (with Change 3)). The AIM is FAA guidance, not regulation. Verify against the official source before relying on it operationally.
Is this a regulation?
No — this is FAA guidance, not a regulation.
Aeronautical Information Manual. FAA operational guidance and recommended practices. The AIM is not regulatory, although it often explains how to comply with regulations.