AET Communication Systems 3 — Questions and Answers
Question 1: What is the primary function of an audio control panel (ACP) in an aircraft?
- Generate audio tones
- Select and route audio between radios, navigation receivers, and crew headsets (Correct answer)
- Amplify RF signals
- Control autopilot audio alerts
Correct answer: Select and route audio between radios, navigation receivers, and crew headsets
The Audio Control Panel allows crew members to select which radio or nav receiver audio they hear and which microphone/radio they transmit on.
Question 2: What does ACARS stand for?
- Aircraft Communication Addressing and Reporting System (Correct answer)
- Automatic Circuit Alert and Response System
- Airborne Communication and Radar System
- Aviation Communication Archive and Relay Service
Correct answer: Aircraft Communication Addressing and Reporting System
ACARS (Aircraft Communication Addressing and Reporting System) is a digital datalink system for transmitting short messages between aircraft and ground stations.
Question 3: What frequency does the emergency guard channel operate on in aviation?
- 108.0 MHz
- 121.5 MHz (Correct answer)
- 131.8 MHz
- 156.8 MHz
Correct answer: 121.5 MHz
121.5 MHz is the international aviation emergency (guard) frequency monitored continuously by ATC and rescue services.
Question 4: What is the impedance of a standard aviation VHF antenna system?
- 75Ω
- 50Ω (Correct answer)
- 300Ω
- 600Ω
Correct answer: 50Ω
Aviation VHF antenna systems are designed for 50-ohm impedance to match standard coaxial cables and transceiver output stages.
Question 5: In aircraft interphone systems, what is the purpose of a hot microphone (hot mic) mode?
- Record all crew conversations to CVR
- Allow continuous open-mic communication without PTT (Correct answer)
- Boost microphone gain for weak signals
- Enable passenger PA announcements
Correct answer: Allow continuous open-mic communication without PTT
Hot microphone mode keeps the microphone continuously active so crew can communicate hands-free without pressing the push-to-talk switch.
Question 6: Which regulation governs avionics communication equipment approval in the US?
- FAR Part 23 only
- TSO (Technical Standard Order) standards (Correct answer)
- FCC Part 97
- RTCA DO-178 exclusively
Correct answer: TSO (Technical Standard Order) standards
FAA Technical Standard Orders (TSOs) define minimum performance standards that aviation communication equipment must meet for approval and installation.
AET Communication Systems 3
What is the primary function of an audio control panel (ACP) in an aircraft?