What is the standard radius for an airspace around most aerodromes with a longest runway of 1850 m or less?

The standard radius for airspace around aerodromes with a longest runway of 1850 m or less is set at 2.0 nautical miles. This regulation is designed to ensure safety and efficient airspace management by providing an appropriate buffer zone around smaller airports. The radius allows for the operation of aircraft while minimizing the risk of interference with other air traffic.

Having a radius of 2.0 nautical miles strikes a balance between providing enough space for approaching and departing aircraft and maintaining efficient use of the airspace. It is important for pilots to be aware of these dimensions when planning their flights, as they impact how close to the airport other aircraft can operate and provide essential information regarding air traffic control communications and procedures in the vicinity of the aerodrome.

In considering the other options, smaller or larger radii would not align with standardized practices for safety and operational efficiency in such environments.