What is the maximum authorized airspeed for aircraft below 10,000 feet MSL?

The maximum authorized airspeed for aircraft operating below 10,000 feet MSL is indeed 250 KIAS (Knots Indicated Airspeed). This regulation is primarily established to promote safety and reduce the risk of mid-air collisions in controlled airspace. Below 10,000 feet, air traffic is generally denser, as more aircraft are operating in the vicinity of airports and during approach or departure phases.

The 250 KIAS limit ensures that aircraft maintain controllable performance at lower altitudes where maneuverability can be crucial. Furthermore, adherence to this speed limit aids air traffic controllers in managing and separating traffic effectively, enhancing safety in the skies. Flying above this threshold can lead to complications such as exceeding the aircraft's maneuvering capabilities and incurring more significant separation and communication challenges.

This regulation is part of the broader set of airspeed limits imposed by the Federal Aviation Administration (FAA) and other aviation authorities to ensure a standardized operating environment, thereby mitigating risks associated with flight operations in more congested airspace.