What is the minimum altitude for autopilot operation during a standard ILS approach with an operational radio altimeter?

During a standard ILS (Instrument Landing System) approach with an operational radio altimeter, the minimum altitude for autopilot operation is indeed 50 feet. This altitude is critical because it allows the autopilot system to maintain control of the aircraft during the final stages of the approach and landing.

The reasoning behind setting this altitude is primarily for safety and precision. At 50 feet, the autopilot can effectively manage the descent rate and adjust for any minor deviations from the glide slope or localizer required for a safe landing. Additionally, many aircraft systems will disable the autopilot at this altitude to ensure that the pilot has full control for a safe and accurate touchdown, particularly in case of any unexpected issues that require manual intervention.

The specifications for minimum autopilot operation altitudes are based on both regulatory standards and operational best practices, ensuring that pilots have the required profiles to conduct landings safely while still allowing for automation to assist in reducing workload during a critical phase of flight.