What is the minimum speed at which pilots may request a closed pattern?

The minimum speed at which pilots may request a closed pattern is established to ensure safe and efficient operations during approach and landing phases. This speed requirement helps maintain sufficient airflow over the control surfaces of the aircraft, enabling effective maneuvering during the turn back to the runway.

Requesting a closed pattern at 140 KIAS allows pilots to manage their airspeed and maintain a safe margin above stall speeds, especially in configurations that may include flaps or gear deployment. Operating at this speed also facilitates better traffic management within the controlled airspace, ensuring that the aircraft can complete a safe and structured circuit pattern around the airfield.

Choosing speeds that are too low could compromise safety, particularly with respect to aircraft performance during the critical phases of flight, while excessive speeds may reduce maneuverability and increase the risk of a go-around scenario. Therefore, 140 KIAS is established as the effective minimum threshold for closed pattern requests, balancing safety and operational efficiency.