Which system helps maintain altitude in RVSM airspace?

The automatic altitude control system is specifically designed to help maintain the designated altitude within Reduced Vertical Separation Minimum (RVSM) airspace. RVSM requires an aircraft to maintain its altitude accurately to ensure safe separation between aircraft flying at similar altitudes.

This system uses various inputs, including altitude information from onboard altimeters and other avionics systems, to automatically make adjustments to the aircraft's flight controls. By continuously monitoring altitude and making necessary corrections, the automatic altitude control system helps maintain compliance with the strict altitude tolerances defined by RVSM regulations, thereby enhancing safety and efficiency in crowded airspaces.

While the other systems mentioned, such as the automatic navigation system, inertial navigation system, and flight management system, play important roles in overall aircraft operation, they are not specifically designed for altitude maintenance within RVSM airspace. The automatic altitude control system is tailored to ensure accurate level flight, which is critical for the safety protocols established for RVSM operations.