Certified Flight Instructor - Flight Instructor Airplane Practice Exam

When air traffic control provides radar traffic information using a clock reference, what basis do they use?

1. The true course of the aircraft.

2. The aircraft's ground track.

3. The magnetic heading of the aircraft.

4. The airspeed of the aircraft.

The correct answer is: The aircraft's ground track.

When air traffic control provides radar traffic information using a clock reference, they use the aircraft's ground track as the basis. The ground track refers to the actual path that the aircraft traces over the ground, which is determined by both its heading and the effects of wind. Using a clock reference is a common method employed by air traffic controllers to relay the position of other aircraft in relation to the receiving aircraft. For example, if traffic is reported at "3 o'clock," it means that the traffic is located to the right side of the aircraft's current ground track. This method provides pilots with a clear and intuitive way to understand their position relative to other aircraft, enhancing situational awareness and safety during flight. The other options, such as true course, magnetic heading, or airspeed, do not provide the point of reference that incorporates wind effects or the actual movement across the ground, making them less relevant in this context. By focusing on the ground track, controllers ensure that pilots receive accurate and practical positioning information based on where the aircraft is actually traveling rather than where it may be pointed.