Free UK CAA Part-66 Module 12 Helicopter Aerodynamics, Structures and Systems (B1.3) Practice Questions

Sample Practice Questions

Try these 10 sample questions from the UK CAA Part-66 Module 12 Helicopter Aerodynamics, Structures and Systems (B1.3) practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1Why does hovering close to a smooth, hard surface require less power than hovering out of ground effect under otherwise similar conditions?

   1. A.The rotor's profile drag is eliminated by surface pressure.
   2. B.Reduced induced flow decreases the rotor's induced drag.Correct answer: B
   3. C.The engine gains power because compressor speed increases.
   4. D.The tail rotor loses thrust, reducing the main rotor's load.

   Explanation: The handbook states, "Since the induced flow velocities are decreased, the AOA is increased, which requires a reduced blade pitch angle and a reduction in induced drag." The reduced induced-power demand explains the lower hover power requirement. This is an airflow effect, not an engine power increase or elimination of profile drag.

   Reference: FAA Helicopter Flying Handbook — Aerodynamics of Flight — Chapter 2, In Ground Effect (IGE), page 2-12

2. 2What is the objective of main rotor blade tracking?

   1. A.Making all blade tips follow the same path during rotationCorrect answer: A
   2. B.Making the rotor's centre of gravity coincide with the mast
   3. C.Making each blade carry the same static balance weight
   4. D.Making all blades have the same chordwise mass position

   Explanation: The handbook states, "The purpose of blade tracking is to bring the tips of all blades into the same tip path throughout their entire cycle of rotation." Tracking concerns the rotating tip paths. The other choices concern mass balance rather than the geometric track.

   Reference: FAA Aviation Maintenance Technician Handbook — Airframe — Chapter 2, Rotor Blade Tracking, page 2-30

3. 3A thin-walled structural member is bent without twisting. Which stress distribution is expected across the bend?

   1. A.Compression on both the inside and outside
   2. B.Tension on the inside and compression outside
   3. C.Compression on the inside and tension outsideCorrect answer: C
   4. D.Torsion on the inside and shear outside

   Explanation: The handbook states, "The rod in Figure 1-14E has been shortened (compressed) on the inside of the bend and stretched on the outside of the bend." Bending combines compression and tension across the section. Reversing those sides or substituting torsion does not match the stated pure bending condition.

   Reference: FAA Aviation Maintenance Technician Handbook — Airframe — Chapter 1, Major Structural Stresses, page 1-6

4. 4Which pressure source supplies a conventional pressure altimeter?

   1. A.Pitot total pressure
   2. B.Atmospheric static pressureCorrect answer: B
   3. C.Engine manifold pressure
   4. D.Instrument vacuum-system pressure

   Explanation: The source states, "In aircraft, it is connected to the static vent(s) via tubing in the pitot-static system." The altimeter is connected to ambient static pressure. Pitot total pressure belongs to airspeed sensing, manifold pressure measures engine induction conditions, and vacuum pressure powers certain gyros rather than sensing altitude.

   Reference: FAA Aviation Maintenance Technician Handbook — Airframe — Chapter 10, Altimeters & Altitude, page 10-15

5. 5For a UK commercial air transport helicopter flight-crew seat, what response must the upper-torso restraint provide during rapid deceleration?

   1. A.Automatically release the shoulder restraint during deceleration
   2. B.Permit the shoulder reel to pay out freely during deceleration
   3. C.Automatically restrain the torso during rapid decelerationCorrect answer: C
   4. D.Lock the shoulder reel only after manual pilot selection

   Explanation: The source states, "a device that will automatically restrain the occupant’s torso in the event of rapid deceleration on each flight crew seat" The required response is automatic torso restraint during rapid deceleration. Automatic release or unrestricted payout defeats restraint, and manual-only locking does not provide the required automatic response.

   Reference: UK CAA Air Operations — Helicopter seats and restraints — CAT.IDE.H.205(a)(5)

6. 6Why can a fuel-tank boost pump reduce the risk of vapour lock in the supply line?

   1. A.It lowers fuel-line pressure to draw vapour toward the engine
   2. B.It supplies liquid fuel to the engine under positive pressureCorrect answer: B
   3. C.It heats the fuel to encourage vapour bubbles to leave solution
   4. D.It increases suction lift between the tank and engine-driven pump

   Explanation: The source states, "The use of boost pumps located in the fuel tank that force pressurized liquid fuel to the engine is most common." Positive supply pressure opposes vapour formation. Reduced pressure or greater suction lift promotes vaporization, as does heating rather than the stated pressurized-liquid supply.

   Reference: FAA Aviation Maintenance Technician Handbook — Airframe — Chapter 14, Vapor Lock

7. 7In aircraft ice-protection systems, what distinguishes anti-icing from de-icing?

   1. A.Anti-icing removes existing ice; de-icing prevents its formation
   2. B.Anti-icing prevents formation; de-icing removes accumulated iceCorrect answer: B
   3. C.Anti-icing is always chemical; de-icing is always electrical
   4. D.Anti-icing is ground-only; de-icing is flight-only

   Explanation: The source states, "Anti-icing equipment is turned on before entering icing conditions and is designed to prevent ice from forming." The corresponding de-icing description concerns removing ice after it begins accumulating. The distinction is preventive versus removal function, not a universal energy-source or ground/flight restriction.

   Reference: FAA Aviation Maintenance Technician Handbook — Airframe — Chapter 15, Ice Control Systems

8. 8Which position-light colour arrangement identifies an aircraft's left side, right side and rear respectively?

   1. A.Green, red and white
   2. B.White, green and red
   3. C.Red, white and green
   4. D.Red, green and whiteCorrect answer: D

   Explanation: The handbook states, "The green light unit is always mounted at the extreme tip of the right wing. The red unit is mounted in a similar position on the left wing. The white unit is usually located on the vertical stabilizer" The colour convention is red left, green right and white aft. The quoted fixed-wing installation illustrates that side/rear convention; the question does not require wing-mounted lamps on a helicopter.

   Reference: FAA Aviation Maintenance Technician Handbook — Airframe — Chapter 9, Position Lights

9. 9Which arrangement characterizes an integrated modular avionics platform?

   1. A.Each function runs on its own dedicated standalone computer
   2. B.Several applications use a shared hardware/software platformCorrect answer: B
   3. C.Dedicated function computers share wiring but not computing resources
   4. D.Redundant computers run one function each without shared application hosting

   Explanation: The source describes IMA as a "Shared set offlexible, reusable, and interoperable hardware and software resources that, when integrated, form a platform that provides services." Shared platform resources host applications. Sharing wiring alone, duplicating a dedicated-function computer or retaining standalone computers does not provide shared application hosting.

   Reference: FAA AC 20-170 — Integrated Modular Avionics — Appendix E, Integrated modular avionics

10. 10What is the primary information-management role of an aircraft electronic library?

    1. A.Store, update and retrieve digital documents that replace paper informationCorrect answer: A
    2. B.Record only raw flight parameters for accident investigation
    3. C.Generate the control commands that directly move flight-control actuators
    4. D.Measure radio-signal phase to determine bearing from a navigation station

    Explanation: The source states, "The units and components which furnish a means of storing, updating and retrieving digital information traditionally provided on paper, microfilm or microfiche." The stated information-system function is digital document storage, updating and retrieval. Flight recording, actuator control and navigation-signal measurement are different functions.

    Reference: UK Part-66 Appendix I — Module 12 system descriptions — Module 12, 12.19 Information Systems (ATA46)