What is the circling area and obstacle clearance for CAT D aircraft?

The circling area and obstacle clearance for Category D (CAT D) aircraft are essential for ensuring safe operations during the circling approach segment. For CAT D aircraft, the standardized conditions set forth in relevant aviation regulations specify that the circling area extends to 5.28 nautical miles from the runway threshold. This distance accounts for the larger wingspan and other operational characteristics of CAT D aircraft, providing adequate space to maneuver safely.

Moreover, the obstacle clearance required during the circling approach for CAT D aircraft is established at 400 feet. This clearance is vital for maintaining safety margins above any obstacles that may be present in the vicinity of the circling area, ensuring that the aircraft can conduct the approach without inadvertently flying into hazards.

In summary, the selection of the first option is based on the recognized standards for CAT D aircraft, taking into account their size, operational capabilities, and the need for adequate safety margins in both distance and altitude during circling approaches.