AET Communication Systems 5

Question 1

A CVR (Cockpit Voice Recorder) is required to retain audio from the last:

Accepted Answer

2 hours of flight

Answer

Current regulations (14 CFR 91.609) require CVRs to retain at least 2 hours of the most recent audio to capture enough data for accident investigation.

Question 2

Ground-wave propagation is associated with which frequency range used in aviation?

Accepted Answer

HF (2–30 MHz)

Answer

HF radio uses both ground-wave (for short ranges) and sky-wave (ionospheric reflection for long ranges), making it essential for oceanic and remote-area communications.

Question 3

When troubleshooting a SATCOM system showing 'no log-on' status, the technician should FIRST check:

Accepted Answer

Antenna pointing, obstructions, and satellite network log-on status

Answer

A 'no log-on' indication most often results from physical blockage, antenna attitude error, or a lapsed network subscription before any internal hardware fault.

Question 4

The purpose of the 'guard' receiver in a VHF comm radio is to:

Accepted Answer

Simultaneously monitor 121.5 MHz emergency frequency while operating on another channel

Answer

A guard receiver continuously monitors 121.5 MHz (the international emergency frequency) in parallel with the main operational channel.

Question 5

A passenger address (PA) amplifier on a transport category aircraft fails silently — no audio in cabin, no fault indication. The BEST initial test is:

Accepted Answer

Inject a known audio signal at the amplifier input and measure output at speaker tap points

Answer

Signal injection at the amplifier input and probing the output isolates whether the fault is in the amplifier itself or in upstream audio sources and wiring.

(AET) Aircraft Electronics Technician Practice Test

(AET) Aircraft Electronics Technician Practice Test

AET Communication Systems 5