A determination can be made as to whether an aircraft on the ground has an operable receiver, but NO transmitter, by asking the pilot to ___.

• A. rock the wings
• B. transmit on emergency frequency
• C. move the rudders
• D. make a hand signal

Answer: (C)

The test is about confirming a working receiver when the aircraft’s radio cannot transmit. If you send a command over the ground-to-air radio and the pil ot can hear it, he will move the rudders in response. Observing that observable control movement shows the receiver is operating, since the instruction was received. If the receiver were bad, the pilot wouldn’t hear the command and the rudders wouldn’t move.

Why the other options don’t fit: wing movement signals are not a direct test of the radio’s ability to receive; asking the pilot to transmit on an emergency frequency would probe the transmitter, which isn’t present here; and using a hand signal tests visual signaling capability rather than the aircraft’s radio receiver.