When operating below 10,000 ft AMSL in ICAO airspace, what is the speed limit?

In ICAO airspace, the designated speed limit when operating below 10,000 feet Above Mean Sea Level (AMSL) is established as 250 knots Indicated Airspeed (IAS). This regulation aims to ensure safety and manage air traffic effectively in congested airspace, particularly near airports where aircraft operations are prevalent.

Setting this limit helps reduce the likelihood of high-speed conflicts and collisions between aircraft during critical phases of flight such as takeoff and landing. It also allows for better management of wake turbulence and provides pilots with adequate reaction times to avoid potential hazards.

Aircraft may exceed this speed limit when operating on specified airways or outside controlled airspace when circumstances permit. However, within the confines of managed airspace and below 10,000 feet, the 250 knots IAS limitation is fundamental to maintaining a safe and orderly flow of air traffic.