In radar, when separating a helicopter departure from another aircraft using course divergence, what is treated as the runway centerline for the helicopter?

• A. The helicopter takeoff course
• B. The helicopter landing path
• C. The helicopter flight plan
• D. The aircraft centerline

Answer: (A)

The concept being tested is using course divergence to keep two aircraft on separate paths by measuring an angular difference from a fixed reference line. For a helicopter that is departing, that fixed reference line is treated as the helicopter’s runway centerline—its takeoff course. In radar separation, you establish the helicopter’s initial departure direction as the baseline, and ensure the other aircraft’s path diverges from that baseline by the required amount. This makes sense because the helicopter is moving away from the runway along its takeoff direction, so that takeoff course serves as the stable reference for calculating separation.

The other options don’t fit because the helicopter’s landing path reflects where it might go later, not its immediate departure reference; the flight plan isn’t a real-time separation reference, and the aircraft centerline would refer to the other aircraft, not establish the helicopter’s baseline.