FAA Ground School Practice Test

What is a situation when a pilot might need to use a transponder code other than the one designated for VFR?

1. Entering Class C airspace

2. When in an emergency situation

3. While flying over a national park

4. During taxi operations

The correct answer is: When in an emergency situation

Using a transponder code other than the one designated for VFR is essential during an emergency situation. In the event of an emergency, pilots are instructed to set their transponder to the emergency code 7700, which alerts air traffic control and nearby aircraft to the situation. This enables a more immediate response from air traffic services, facilitating their assistance. While entering Class C airspace typically requires a specific transponder code, it does not warrant the need to switch to an emergency code, as the VFR transponder code would suffice in that scenario. Similarly, flying over a national park or during taxi operations usually does not involve the use of an alternative transponder code unless prompted by air traffic control or other specific regulations. Therefore, setting the transponder to 7700 during an emergency is the recommended procedure to ensure maximum visibility and urgency in the situation.