When is a pilot required to notify ATC when operating in RVSM airspace?

A pilot is required to notify ATC as soon as possible if required equipment fails while operating in Reduced Vertical Separation Minimum (RVSM) airspace because the integrity of RVSM operations relies on specific altitude-keeping performance. In RVSM airspace, aircraft must be equipped with certain avionics, such as altitude-keeping equipment, that ensure they can maintain their assigned altitude within strict tolerances. If any of this critical equipment becomes inoperative, the pilot must inform ATC immediately to avoid potential altitude conflicts with other aircraft.

This immediate notification allows ATC to take necessary actions, such as providing alternate routing or altitude assignments, to maintain safe separation between aircraft. Operating in RVSM airspace without the required equipment or with a failure poses risks not only to the aircraft in question but also to the safety of all aircraft operating within that airspace.

This requirement stems from regulations aimed at ensuring the safety and efficiency of air traffic operations in densely traveled areas where RVSM is implemented.