Where are the transponder antennas located?

• A. Forward fuselage, Top of vertical stabilizer
• B. In the cockpit behind the dash
• C. Forward doghouse fairing, Underside of tail boom
• D. On the wingtips and leading edge

Answer: (C)

Transponder antennas are placed where they have a clear line of sight to the sky and away from major airframe interference, and helicopters typically use two antennas to ensure reliable coverage. One is mounted on the forward doghouse fairing near the cockpit to get a good elevation view and avoid rotor/airframe shadowing, while the other is mounted on the underside of the tail boom to maintain a clear, low path to the transponder signals. This combination provides robust, consistent performance in different attitudes and flight conditions.

Locations like inside the cockpit behind the dash would not radiate effectively and could be blocked by the aircraft structure. Wingtip or leading-edge placements are more associated with other systems (like certain nav or comm antennas) and aren’t the standard setup for helicopter transponders.