What must non-RVSM aircraft report when entering RVSM airspace?

• A. Negative RVSM
• B. Positive RVSM
• C. RVSM unavailable
• D. Altitude out of limits

Answer: (A)

Entering RVSM airspace, aircraft that cannot meet RVSM requirements must inform ATC that they are negative RVSM. This declaration signals to controllers that the aircraft cannot maintain the standard RVSM vertical separation, so ATC will avoid assigning RVSM altitudes to them and will apply appropriate non-RVSM separation and altitude blocks. RVSM airspace relies on precise altitude-keeping and cross-checks between two independent altitude systems; when an aircraft cannot meet these criteria, the controller needs to know so safety margins are preserved.

In practice, if an aircraft is RVSM-capable it would be treated as such, and if the status were unavailable or uncertain, the controller would handle it through standard ATC procedures. Altitude out of limits would indicate a different issue, not the reporting of RVSM capability.