What is a requirement for an aircraft to operate in RVSM airspace aside from altitude systems?

For an aircraft to operate in Reduced Vertical Separation Minimum (RVSM) airspace, it is essential to have an altitude alert system. This system plays a crucial role in ensuring that the aircraft maintains precise altitude control, which is vital for safety in RVSM airspace, where aircraft fly at altitudes separated by only 1,000 feet instead of the traditional 2,000 feet. The altitude alert system alerts pilots when the aircraft deviates from its assigned altitude, promoting adherence to altitude assignments and enhancing overall safety.

While other components like an operational transponder and pilot training certification are important for general aviation operations, they do not specifically address the requirements needed for RVSM compliance. The altitude alert system directly supports the operational standards set for RVSM airspace, making it a necessary requirement alongside accurate altitude measuring and reporting systems.