Systems Repair Practice Exam Questions

FAA Repairman Certificate – Aircraft Radio Systems Repair Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary function of an aircraft VHF communication system?
• To provide long-range communication beyond the horizon
• To provide short-range line-of-sight communication between aircraft

and ground stations

• To communicate with satellites directly
• To control aircraft navigation automatically

Rationale: VHF communication systems operate on line-of-sight

frequencies, typically between 118 and 136 MHz, ideal for short-range air- to-ground communication.

• What frequency range is allocated for aircraft VHF communication?
• 108–117.95 MHz 1 / 4

• 118–136.975 MHz
• 200–400 MHz
• 2–30 MHz

Rationale: The VHF communication band for aviation is 118–136.975 MHz

as per ICAO and FAA frequency allocations.

• What is the purpose of a transponder in an aircraft radio system?
• To transmit voice signals
• To measure altitude
• To reply to interrogation signals from radar systems
• To receive navigation signals only

Rationale: The transponder automatically responds to radar interrogations

from ATC, identifying the aircraft and altitude.

• Mode C in an aircraft transponder transmits which additional

information?

• Flight plan data
• Pressure altitude
• Airspeed
• Heading

Rationale: Mode C adds pressure altitude data from the encoder to the

transponder’s identification reply. 2 / 4

• Which frequency band is used by the aircraft transponder system?
• 108–118 MHz
• 1030 MHz (interrogation) and 1090 MHz (reply)
• 406 MHz
• 400–500 MHz

Rationale: ATC radar sends interrogation pulses at 1030 MHz and the

aircraft transponder replies at 1090 MHz.

• What is the purpose of the squelch circuit in a communication receiver?
• To boost weak signals
• To increase bandwidth
• To suppress receiver noise when no signal is present
• To improve transmitter output

Rationale: Squelch mutes background noise in the absence of a received

carrier, improving audio clarity.

• What type of modulation is used in VHF aircraft communications?
• Frequency Shift Keying
• Amplitude Modulation (AM)
• Amplitude Modulation (AM)
• Frequency Modulation (FM) 3 / 4

Rationale: Aviation VHF communications use AM for compatibility and

interference detection.

• What is the function of the antenna coupler in an HF communication

system?

• To amplify signals
• To match antenna impedance to transmitter output impedance
• To convert frequency
• To store transmission data

Rationale: The coupler ensures maximum power transfer between

transmitter and antenna by impedance matching.

• The HF communication system typically operates in which frequency

range?

• 30–300 MHz
• 2–30 MHz
• 118–137 MHz
• 960–1215 MHz

Rationale: HF (High Frequency) systems for long-range communications

operate between 2 and 30 MHz.

• / 4