What is the typical protected circling radius for the Cessna 172?

The typical protected circling radius for a Cessna 172 is indeed 1.3 nautical miles. This measurement is derived from standard criteria established for aircraft in the circling approach procedure. The protected area ensures that there is a safe margin around the aircraft during its maneuvering in the circling phase, accounting for various factors such as maneuverability, turn radius, and airspeed.

Circling approaches are particularly important because they allow for landing on runways that are not aligned with the instrument approach path. The 1.3 nm radius provides a sufficient buffer to maintain safe separation from obstacles and terrain while enabling the pilot to execute the necessary maneuvers safely. This radius is calibrated to the performance characteristics of light aircraft like the Cessna 172, ensuring that it can safely navigate within this distance while maintaining appropriate altitude and control.

Understanding this radius is crucial for pilots flying in conditions requiring instrument approaches, as it influences flight planning and navigation during those approaches.