Originally Posted by
BoilerUP
Its necessary to have automation at 30,000ft because RVSM airspace starts at FL290 and goes up to FL410, and the FARs require use of an autopilot for cruise in RVSM airspace.
Originally Posted by
PerfInit
The mandatory use of autopilot in RVSM airspace is a safety risk mitigation requirement to help prevent altitude deviations.
To clarify, the FARs require an operational autopilot. There is no requirement in the FARs that it be engaged. Approved manuals for part 121 or 135 operators may have more strict requirements than the FARs.