Which of the following is NOT a method of identifying an aircraft with Primary Radar Identification?

In the context of Primary Radar Identification, the correct answer highlights the methods typically employed for identifying aircraft in a radar system. Primary radar relies on the return of radar signals from the aircraft rather than relying on transponders or other active systems.

Tracking an aircraft based on altitude deviation is not a method of identifying an aircraft with primary radar. Primary radar systems detect the position of an aircraft through reflected radar waves; altitude changes alone do not provide sufficient information for unequivocal identification. Thus, without a transponder or additional data that confirms altitude information, primary radar cannot ascertain an aircraft's identity based solely on altitude deviations.

The other methods listed are valid techniques for identification using primary radar. Observing a departing aircraft target within a mile of the runway allows air traffic controllers to verify the position of the aircraft relative to the airport. Position correlation based on reported position uses data from the aircraft's movements and position reports to confirm its identity on radar. Similarly, observing a target making significant turns (30 degrees or more) can help controllers identify and track the aircraft as it maneuvers, particularly when the primary radar provides real-time positional data.