Download Avionics AVN Practice Exam and more Exams Technology in PDF only on Docsity!
Question 1. Which material is most commonly used for antenna mounting brackets on modern composite airframes? A) Aluminum alloy B) Titanium alloy C) Carbon‑fiber reinforced polymer D) Steel Answer: A Explanation: Aluminum offers good conductivity for grounding while being lightweight and easy to fabricate, making it the preferred choice for antenna brackets on composite structures. Question 2. In aircraft electrical bonding, the primary purpose of a bonding strap between the engine case and the airframe is to: A) Reduce engine vibration B) Provide a return path for static electricity C) Increase engine power output D) Prevent fuel leakage Answer: B Explanation: Bonding straps create a low‑impedance path for static discharge, protecting avionics from electromagnetic interference.
Question 3. Which flight control surface is directly actuated by the autopilot’s roll channel? A) Elevator B) Rudder C) Aileron D) Flap Answer: C Explanation: The roll channel commands the ailerons to produce the desired roll attitude. Question 4. At 30,000 ft, the typical ambient temperature range that avionics equipment must tolerate is: A) - 10 °C to +40 °C B) - 40 °C to +55 °C C) 0 °C to +70 °C D) - 55 °C to +30 °C Answer: B Explanation: Avionics are certified for the extreme cold of high altitude and the heat generated by equipment, usually – 40 °C to +55 °C.
Question 7. Which component regulates the voltage output of a brushless alternator on a transport aircraft? A) Transformer‑rectifier unit (TRU) B) Voltage regulator (AVR) C) Battery charger D) Load shed relay Answer: B Explanation: The automatic voltage regulator maintains constant alternator output despite load changes. Question 8. A lithium‑ion aircraft battery is rated at 200 Ah. Its usable capacity after applying the 80 % depth‑of‑discharge rule is: A) 160 Ah B) 200 Ah C) 120 Ah D) 180 Ah Answer: A Explanation: 200 Ah × 0.80 = 160 Ah usable to preserve battery life.
Question 9. The most appropriate circuit protection device for a high‑current avionics bus that must be reset without removal is: A) Blade fuse B) Resettable polyfuse C) Push‑pull circuit breaker D) Thermal overload relay Answer: C Explanation: Push‑pull breakers can be manually reset after a fault clears. Question 10. According to ANSI/ASME Y14.44, the symbol for a “ground” connection on a wiring diagram is: A) A triangle with a line B) A circle with a “G” inside C) A line with three short parallel lines beneath it D) A square with a minus sign Answer: C Explanation: The standard ground symbol is a line with three parallel lines beneath it.
Question 13. When terminating a coaxial cable for a VHF antenna, the most critical factor to maintain signal integrity is: A) Length of the outer jacket B) Proper 50 Ω impedance matching C) Use of a red‑colored connector D) Adding a fuse in series Answer: B Explanation: Maintaining the characteristic impedance avoids reflections and loss. Question 14. A VHF transceiver’s channel spacing of 25 kHz allows a maximum of how many discrete channels between 118.000 MHz and 136.975 MHz? A) 800 B) 840 C) 720 D) 960 Answer: B Explanation: Frequency range = 18.975 MHz; 18.975 MHz ÷ 0.025 MHz = 759 channels, rounded to the nearest standard allocation of 840 channels across the band.
Question 15. AM modulation is used in VHF aircraft communications because: A) It provides higher data rates than FM B) It is less susceptible to multipath fading C) It allows simple receiver design and easy detection of signal loss D) It requires less bandwidth Answer: C Explanation: AM’s envelope detection reveals signal presence; loss of carrier is immediately apparent to pilots. Question 16. The primary function of an ACARS datalink system is to: A) Provide voice communication with ATC B) Transmit aircraft performance data to the airline’s operations center C) Replace the VOR navigation system D) Control the aircraft’s autopilot Answer: B Explanation: ACARS automatically sends and receives operational messages, such as flight plans and maintenance data.
Question 19. When tuning a VOR, the “TO” indication on the CDI appears when: A) The aircraft is north of the station B) The selected radial is inbound to the station C) The VOR is out of service D) The aircraft is on a heading opposite the selected radial Answer: B Explanation: The CDI shows “TO” when the aircraft is on a course that will bring it toward the station. Question 20. DME slant‑range error becomes significant at: A) Low altitude, short distance B) High altitude, long distance C) Medium altitude, medium distance D) Any altitude, any distance Answer: B Explanation: The geometric slant‑range error (line‑of‑sight vs. ground distance) increases with altitude and range. Question 21. The ILS localizer provides lateral guidance by transmitting:
A) Two 90 Hz tones spaced 150 Hz apart B) A single 400 Hz tone with phase modulation C) Two 90 Hz tones spaced 150 Hz apart, one on each side of the carrier D) A 30 Hz amplitude‑modulated signal Answer: C Explanation: The localizer uses a pair of 90 Hz tones 150 Hz apart to create a left‑right pattern. Question 22. Which component of the ILS monitors the integrity of the glideslope signal? A) Marker beacon receiver B) Localizer antenna array C) Glideslope monitor (GSM) D) DME transceiver Answer: C Explanation: The GSM checks for signal loss or distortion and alerts the crew if integrity is compromised. Question 23. An ADF receives signals from an NDB. The primary limitation of NDB navigation is:
B) Detect faulty satellite data and exclude it from the solution C) Provide terrain awareness D) Encrypt the navigation data Answer: B Explanation: Receiver Autonomous Integrity Monitoring evaluates satellite measurements and discards outliers to maintain navigation integrity. Question 26. In an FMS, the “LNAV” mode provides: A) Lateral navigation only B) Vertical navigation only C) Both lateral and vertical navigation D) Autothrottle control Answer: A Explanation: LNAV commands the autopilot to follow the flight plan laterally, without altitude guidance. Question 27. The primary purpose of an inertial reference system (IRS) in modern glass cockpits is to: A) Replace the pitot‑static system completely B) Provide attitude, heading, and position data when GPS is unavailable
C) Generate VHF communication signals D) Control the landing gear Answer: B Explanation: IRS supplies attitude and navigation data independent of external signals, enhancing redundancy. Question 28. During IRS alignment, the “north reference” is established by: A) Using the magnetic compass B) Detecting Earth’s rotation via gyroscopes C) Receiving VOR signals D) Measuring GPS latitude Answer: B Explanation: The inertial platform senses Earth’s rotation to determine true north during alignment. Question 29. An EFIS primary flight display (PFD) typically shows all of the following EXCEPT: A) Airspeed tape B) Attitude indicator C) Engine oil temperature
Answer: B Explanation: Virtual links are pre‑allocated logical channels that ensure deterministic data transfer. Question 32. A Mode S transponder differs from Mode C primarily because it: A) Provides altitude reporting B) Uses selective addressing for individual aircraft identification C) Operates on a different frequency band D) Can only be used in military aircraft Answer: B Explanation: Mode S includes a 24‑bit address, enabling selective interrogation and data link capabilities. Question 33. TCAS Resolution Advisories (RAs) are generated when: A) Two aircraft are within 5 NM horizontally and 1000 ft vertically B) The aircraft’s altitude deviates from the flight plan C) A ground station loses contact with the aircraft D) The autopilot is disengaged Answer: A
Explanation: TCAS issues RAs when a traffic conflict meets defined proximity thresholds. Question 34. The tilt‑control function on a weather radar antenna is used to: A) Adjust the antenna’s frequency B) Change the elevation angle to scan different altitudes C) Increase the radar’s power output D) Switch between weather and terrain mapping modes Answer: B Explanation: Tilting the antenna changes the scan elevation, allowing pilots to view weather at various altitudes. Question 35. EGPWS “Terrain Ahead” alerts are triggered by: A) Radar returns from ground‑mapping equipment B) A database comparison of aircraft position and known terrain elevations C) Pilot‑entered visual observation D) The aircraft’s transponder Answer: B Explanation: EGPWS continuously compares GPS‑derived position with a terrain database to generate alerts.
Question 38. A pitot‑static leak test is commonly performed by: A) Pressurizing the system with nitrogen and checking for pressure drop B) Immersing the pitot tube in water and looking for bubbles C) Applying a vacuum to the static ports D) Measuring the temperature of the pitot line Answer: A Explanation: Pressurizing with a known gas and monitoring pressure decay detects leaks. Question 39. The maintenance manual that provides part numbers, torque values, and removal procedures for a specific avionics component is called: A) Illustrated Parts Catalog (IPC) B) Component Maintenance Manual (CMM) C) Aircraft Flight Manual (AFM) D) Service Bulletin (SB) Answer: B Explanation: The CMM contains detailed technical data for component repair and replacement.
Question 40. An Airworthiness Directive (AD) that requires a repetitive inspection of a wiring harness every 500 flight hours is classified as: A) Mandatory continuing airworthiness requirement B) Optional service bulletin C) Supplemental type certificate amendment D) Manufacturer’s recommendation Answer: A Explanation: ADs are mandatory regulatory actions to correct unsafe conditions. Question 41. The “half‑splitting” troubleshooting technique is used to: A) Reduce the voltage on a circuit by 50 % B) Isolate a fault by dividing a system into two equal sections and testing each C) Duplicate a component for redundancy D) Perform a simultaneous test on two unrelated systems Answer: B Explanation: By testing halves of a circuit, the technician narrows the location of a failure. Question 42. Intermittent faults caused by vibration are best reproduced by: A) Applying a steady DC voltage
