What is one of the necessary requirements to enter RVSM airspace?

To operate in Reduced Vertical Separation Minimum (RVSM) airspace, the requirement for having two altimeters is crucial. This standard is essential because RVSM airspace allows aircraft to fly at altitudes between 29,000 feet and 41,000 feet with only 1,000 feet of vertical separation between aircraft. The presence of two altimeters is necessary to ensure accuracy and redundancy in altitude measurement. In the event one altimeter fails or provides incorrect readings, the other can be relied upon to maintain safe flight levels and prevent potential altitude conflicts with other aircraft.

The requirement for two altimeters directly addresses safety concerns in RVSM operations, as reliable and accurate altitude information is critical for the safe operation of all aircraft in this busy airspace.