FAA Ground School Practice Test

If Air traffic control advises that radar service is terminated when the pilot is departing Class C airspace, what transponder code should be set?

1. 1200

2. 7500

3. 7600

4. 7700

The correct answer is: 1200

Setting the transponder code to 1200 is the correct response when radar service is terminated while departing Class C airspace. This code designates that the aircraft is operating under VFR (Visual Flight Rules), as opposed to being under the control of ATC, which usually assigns a unique code for tracking purposes. When radar service is no longer in effect, the pilot is responsible for maintaining their own navigation and separation from other aircraft, and reverting to the standard VFR code is essential to communicate that status effectively. This code allows the aircraft to be identified as a non-operational ATC flight, thereby indicating to other pilots and air traffic controllers that it is no longer using ATC services. In contrast, the other codes serve different specific purposes: 7500 indicates a hijacking, 7600 indicates a radio communication failure, and 7700 signals an emergency situation. Using any of these codes while simply transitioning out of radar service would unnecessarily complicate the situation and could result in misunderstandings regarding the aircraft's operational status.