Practice Test Geeks(AET) Aircraft Electronics Technician Practice Test
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Communication Systems Flashcards

7 cards from real AET practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Communication Systems flashcards as text

  1. What is the purpose of SELCAL (Selective Calling System) in aviation communication?

    Answer: To alert a specific aircraft when a ground station wants to communicate

    SELCAL allows ground stations to alert a specific aircraft via a unique 4-tone code, enabling pilots to reduce cockpit audio monitoring on long-haul flights.

  2. Which modulation type is used by standard VHF aviation communication radios for voice transmissions?

    Answer: AM (Amplitude Modulation)

    Aviation VHF communication uses AM because it allows multiple signals to coexist on the same frequency and is compatible with legacy ground infrastructure.

  3. An aircraft HF radio is being checked and exhibits low output power but correct frequency. The MOST likely cause is:

    Answer: Defective PA (power amplifier) stage

    Low output power with correct frequency typically points to a failure in the PA stage, since frequency generation is handled separately by the synthesizer.

  4. What is the frequency range of the aviation VHF communication band?

    Answer: 118.0–136.975 MHz

    Aviation VHF communication operates from 118.0 to 136.975 MHz, while 108–117.95 MHz is reserved for VOR/ILS navigation.

  5. A SATCOM system on an aircraft provides communication primarily via:

    Answer: Geostationary or LEO satellites

    SATCOM uses geostationary (e.g., Inmarsat) or low Earth orbit satellites to relay voice and data communications globally, including over oceans.

  6. During an interphone system check, audio is heard in the cockpit but not at the forward attendant station. Which component is MOST suspect?

    Answer: Interphone amplifier serving the forward cabin zone

    If only one station is silent, the amplifier or wiring serving that specific zone is the most likely fault rather than a shared component.

  7. What does the term 'squelch' refer to in an aviation radio receiver?

    Answer: A circuit that mutes the receiver output in the absence of a valid signal

    Squelch suppresses receiver output when signal strength falls below a threshold, preventing the cockpit from being flooded with static noise between transmissions.