Free CAAS SAR-66 Module 7 Maintenance Practices Practice Questions

Sample Practice Questions

Try these 10 sample questions from the CAAS SAR-66 Module 7 Maintenance Practices practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1Several conductor strands in a portable tool's power cord are broken. Why can continued use create a local fire hazard?

   1. A.The remaining strands carry the current through less conducting metal.Correct answer: A
   2. B.The reduced cross-section necessarily increases the safe current rating.
   3. C.The broken strands act as a fuse that guarantees immediate disconnection.
   4. D.The smaller conducting area removes resistance heating from the cord.

   Explanation: The handbook states, "When several wires inside a power cord are broken, the current passing through the remaining wires increases." Broken strands concentrate current in the remaining conducting area and can cause excessive heat. Reduced area does not increase ampacity, guarantee fuse-like disconnection, or eliminate resistance heating.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 1, Electrical Safety—Fire Safety, p. 1-2

2. 2A previously drilled hole needs a smooth finish and an accurate final diameter. Which hand tool is designed for this operation?

   1. A.A centre punch
   2. B.A bottoming tap
   3. C.A straight reamerCorrect answer: C
   4. D.A countersink cutter

   Explanation: The handbook states, "Reamers are used to smooth and enlarge holes to exact size." Reaming finishes an existing hole. A tap cuts threads, a centre punch marks a drilling location, and a countersink makes a conical recess.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 11, Reamers, p. 11-13

3. 3A printed drawing has been resized during copying. What should determine the manufactured part's dimensions?

   1. A.Measurements scaled from the copied outline
   2. B.The dimensions explicitly stated on the drawingCorrect answer: B
   3. C.The nominal size of the paper used for the copy
   4. D.The magnification selected when the copy was made

   Explanation: The handbook states, "For accurate information, refer to the dimensions shown on the drawing." Copying or zooming can alter the physical image size. Stated dimensions control; paper size, magnification and scaling the copied outline do not establish the required part size.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 4, Scale, p. 4-9

4. 4A de-energised and appropriately isolated wiring run must be tested for insulation leakage under electrical stress. Which instrument is designed for this measurement?

   1. A.A low-resistance bonding meter
   2. B.A frequency counter
   3. C.A clamp-on current meter
   4. D.An insulation-resistance megohmmeterCorrect answer: D

   Explanation: The handbook states, "The chief advantage of the megger over an ohmmeter is its capacity to measure resistance with a high potential, or “breakdown” voltage." This tests insulation under an applied test voltage, using the isolation and test conditions specified for the installation. A bonding meter addresses low resistance, a current clamp measures current, and a frequency counter measures repetition rate.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, Megger (Megohmmeter), p. 12-72

5. 5A newly fabricated aircraft fluid tube has a wrinkled bend. What is the appropriate assessment before installation?

   1. A.Accept it if the fitting nuts can still be tightened.
   2. B.Accept it after compensating with a larger clamp.
   3. C.Do not install it in that condition.Correct answer: C
   4. D.Do not inspect it until the first pressure cycle.

   Explanation: The handbook states, "Tubing with flattened, wrinkled, or irregular bends should not be installed." A bend defect must be corrected or the tube remade as applicable before installation. Tightening a fitting, enlarging a clamp or waiting for service does not remove the bend defect.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 9, Tube Bending, p. 9-3

6. 6Why must sprockets in an aircraft chain transmission be correctly aligned?

   1. A.To prevent the chain riding flanges and chafing nearby guardsCorrect answer: A
   2. B.To make chain lubrication unnecessary after installation
   3. C.To remove the chain's need for correctly fitted attachment links
   4. D.To increase chain tension beyond the manufacturer's setting

   Explanation: CAAIP explains, "All pulleys and sprockets must be aligned to provide a satisfactory 'run' for the cables and chains so preventing riding on the flanges of the pulleys and sprockets and chafing against the guards and covers." Alignment establishes the correct chain path. It does not replace lubrication, attachment security or the prescribed tension setting.

   Reference: CAA Civil Aircraft Airworthiness Information and Procedures — Book 2, Leaflet 20-80, §9.1

7. 7Using the mid-thickness neutral-axis approximation, what bend allowance is required for a 90° bend with an inside radius of 4.0 mm in 1.0-mm sheet? Round to two decimal places.

   1. A.6.28 mm
   2. B.7.85 mm
   3. C.14.14 mm
   4. D.7.07 mmCorrect answer: D

   Explanation: The handbook states, "To the radius of bend (R) add 1⁄2 the thickness of the metal (1⁄2T). This gives R + 1⁄2T, or the radius of the circle of the neutral axis." Under the stated approximation, neutral radius = 4.0 + 0.5(1.0) = 4.5 mm. A 90° arc is one quarter of a circle, so allowance = 2π(4.5)/4 = 7.0686 mm, rounded to 7.07 mm. Ignoring thickness gives 6.28 mm; adding full thickness gives 7.85 mm; using a semicircle gives 14.14 mm.

   Reference: FAA Aviation Maintenance Technician Handbook—Airframe — Chapter 4, Formula 1: Bend Allowance for a 90° Bend, p. 4-63

8. 8Two loads of 600 kg at an arm of 2.0 m and 400 kg at an arm of 3.0 m are measured from the same datum. What is their combined centre-of-gravity arm?

   1. A.2.4 mCorrect answer: A
   2. B.2.5 m
   3. C.2.6 m
   4. D.5.0 m

   Explanation: The handbook gives "CG = Total Moment ÷ Total Weight". Total moment = 600 × 2.0 + 400 × 3.0 = 2400 kg·m; total mass = 1000 kg; CG arm = 2400/1000 = 2.4 m. The 2.5-m answer averages arms without weighting; 2.6 m reverses the load weighting; 5.0 m adds arms.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 6, General Concepts—CG Calculation, p. 6-6

9. 9Inspection reveals characteristic worm-like corrosion tracks beneath an aircraft paint film. Which form of corrosion does this appearance suggest?

   1. A.Filiform corrosionCorrect answer: A
   2. B.Fretting corrosion
   3. C.Exfoliation corrosion
   4. D.Stress-corrosion cracking

   Explanation: The handbook describes filiform corrosion: "It is recognized by its characteristic wormlike trace of corrosion products beneath the paint film." Fretting occurs at moving contact surfaces, exfoliation lifts grains, and stress-corrosion cracking produces cracks under combined stress and environment.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 8, Filiform Corrosion, p. 8-5

10. 10Under SAR-145, a life-limited part reaches its mandatory replacement limit but has no visible damage. What is required?

    1. A.Continue using it until a crack becomes visible
    2. B.Permanently remove it from service on or before the limitCorrect answer: B
    3. C.Reset its accumulated life after cleaning and repainting
    4. D.Replace the mandatory limit with a local visual-inspection interval

    Explanation: The source states, "This part must be permanently removed from service on or before this limit is reached." The mandatory replacement limit controls removal even if a visual check reveals no damage. Appearance, cleaning or a locally chosen inspection interval cannot reset that limit.

    Reference: CAAS SAR-145 Approved Maintenance Organisations — Section 1, Definitions—Life-limited part