lähtöpiirin

Lähtöpiirin, also known as the departure circle, is a concept in aviation and air traffic control that refers to a circular area around an airport's runway from which aircraft are not permitted to take off. This area is established to ensure the safety of aircraft during takeoff and to prevent potential conflicts with other air traffic. The size and shape of the departure circle can vary depending on the specific airport and its operational requirements.

The primary purpose of the lähtöpiirin is to provide a buffer zone for aircraft as they accelerate down the runway. This helps to minimize the risk of mid-air collisions and other potential hazards. Additionally, the departure circle can be used to manage air traffic flow and to coordinate the movements of multiple aircraft taking off from the same airport.

The departure circle is typically defined by a set of rules and procedures that are established by the airport's air traffic control service. These rules may include restrictions on the speed and altitude of aircraft within the departure circle, as well as requirements for pilots to maintain visual contact with the control tower during takeoff.

In some cases, the departure circle may be extended or modified to accommodate specific operational needs, such as the presence of heavy aircraft or adverse weather conditions. However, these modifications are typically subject to approval by the airport's air traffic control service and are designed to ensure the continued safety and efficiency of air traffic operations.

Overall, the lähtöpiirin plays a critical role in the safe and efficient operation of airports and air traffic control services. By providing a buffer zone for aircraft during takeoff and by managing air traffic flow, the departure circle helps to minimize the risk of accidents and to ensure the smooth and orderly movement of aircraft through the airspace.