Federal Aviation Regulations Practice Test 2025 – Complete Exam Prep

The requirement for an operable 4096-code transponder with an encoding altimeter is critical for maintaining safety and situational awareness in controlled airspace. Specifically, this transponder is mandated in Class A, B, and C airspace to enhance the visibility of aircraft to Air Traffic Control (ATC) and to other aircraft.

In Class A airspace, all aircraft must operate under Instrument Flight Rules (IFR) and are required to have a transponder to communicate their altitude and identity to ATC. In Class B airspace, where there is significant traffic density around major airports, the transponder requirement helps manage the flow of air traffic. Similarly, Class C airspace, which typically surrounds airports with a moderate level of traffic, also necessitates the use of a transponder to ensure safe operation and to facilitate communication between ATC and pilots.

The encoding altimeter capability tied to the transponder enhances safety by providing altitude data, allowing ATC to provide vertical separation between aircraft effectively. This requirement does not extend to Class G airspace, where regulations are more relaxed regarding transponder usage, and is not specifically mandated for Class D and E airspace under all conditions.