Practice Test Geeks(UAS) Unmanned Aircraft Systems Certified Practice Test
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Communication Systems and Data Links Flashcards

7 cards from real UAS 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 and Data Links flashcards as text

  1. The 5.8 GHz frequency band is most commonly used for which function in UAS systems?

    Answer: Analog or digital video downlink (FPV transmission)

    The 5.8 GHz band is commonly used for video downlink (FPV) because its higher frequency supports greater bandwidth needed for video, though its range is shorter than the 2.4 GHz C2 band.

  2. In UAS communications, what does 'link budget' describe?

    Answer: The accounting of all signal power gains and losses across a communication link to determine reliability

    A link budget tallies all gains (transmitter power, antenna gain) and losses (path loss, cable loss, atmospheric absorption) to determine whether the received signal will be strong enough for reliable communication.

  3. Which antenna type is best suited for UAS ground station use when the aircraft may fly in any direction from the operator?

    Answer: Omnidirectional antenna

    An omnidirectional antenna radiates and receives signal equally in all horizontal directions, eliminating the need to point the antenna at the aircraft as its bearing changes during flight.

  4. What is the primary operational impact of RF interference on a UAS control link?

    Answer: Degraded or lost link reliability, potentially causing loss of control

    RF interference from devices operating on the same or adjacent frequencies degrades signal quality, which can cause control dropouts or complete loss of the command link, risking loss of aircraft control.

  5. What is the purpose of a 'failsafe' function in a UAS communication system?

    Answer: To execute a pre-programmed response (e.g., return-to-home or land) when the C2 link is lost

    Failsafe functions define automatic aircraft behaviors — such as hovering, returning to home, or landing — that activate when the C2 link is lost, preventing the aircraft from flying away uncontrolled.

  6. In UAS control systems, what does 'latency' refer to?

    Answer: The time delay between a pilot input and the aircraft's execution of that command

    Latency is the round-trip time delay from when a command is sent at the ground station to when the aircraft executes it, which directly affects the pilot's ability to respond to changing flight conditions.

  7. Which U.S. regulatory body is responsible for allocating radio frequency spectrum used by UAS communication systems?

    Answer: FCC (Federal Communications Commission)

    The FCC governs commercial and private radio frequency spectrum use in the United States, including the ISM bands and licensed frequencies used for UAS command and control systems.