What is true about the pilot’s requirement to activate the transponder in relation to an interrogation signal?

When discussing the operation of a transponder in relation to an interrogation signal, it is essential to understand that the transponder is designed to respond automatically to interrogation signals from radar systems. This automatic response is a critical part of how the transponder functions, as it allows aircraft to be identified and tracked by air traffic control.

When an aircraft is interrogated by radar, the transponder will emit a signal back to the radar system without needing the pilot to manually activate it. This ensures that even if the pilot forgets to activate the transponder or if it is set to standby mode, it will still respond automatically to interrogation signals when necessary.

In this context, the answer indicates that the transponder activates automatically regardless of the IDT (Identification) button being pressed. This characteristic is vital for the rapid identification of aircraft by ATC, enhancing overall situational awareness and safety in the airspace.

While other options refer to manual activation, specific flight levels, or non-responsiveness under conditions, they do not accurately describe the operational capability of the transponder in response to interrogation signals. The automatic response feature is a key component required for effective air traffic management.