Free CAAS SAR-66 Category B1 M06 — Materials and Hardware Practice Questions

Sample Practice Questions

Try these 10 sample questions from the CAAS SAR-66 Category B1 M06 — Materials and Hardware practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1What is the principal element in a ferrous aircraft metal?

   1. A.IronCorrect answer: A
   2. B.Aluminum
   3. C.Copper
   4. D.Nickel

   Explanation: The FAA handbook states: "The term “ferrous” applies to the group of metals having iron as their principal element." Ferrous classification depends on iron as the principal element; the other elements name nonferrous base metals.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 7, 7-2, Ferrous Aircraft Metals

2. 2Which principal alloying element identifies the 2xxx aluminum series?

   1. A.CopperCorrect answer: A
   2. B.Magnesium
   3. C.Zinc
   4. D.Silicon

   Explanation: The handbook states: "2xxx—copper" The 2xxx series uses copper; magnesium, zinc and silicon identify other series.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 7, 7-7, Alloy designation

3. 3Which behaviour distinguishes a thermoplastic from a fully cured thermosetting plastic?

   1. A.It softens again when heatedCorrect answer: A
   2. B.It can only be shaped before any heating
   3. C.It forms only by adding metallic reinforcement
   4. D.It remains permanently soft after cooling

   Explanation: The handbook states: "Thermoplastic materials soften when heated and harden when cooled." Thermoplastic softening is reversible; the alternatives confuse curing, reinforcement and permanent softness.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 7, 7-29, Transparent Plastics

4. 4During electrochemical corrosion, which change occurs at the anode?

   1. A.Reduction of the corrosive agent
   2. B.Oxidation of the attacked metalCorrect answer: B
   3. C.Elimination of the conductive path
   4. D.Formation of an electrically isolated cathode

   Explanation: The handbook states: "the metal that is attacked or oxidized suffers what is called anodic change," Anodic change is oxidation; reduction belongs to the cathodic process.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 8, 8-2, Types of Corrosion

5. 5What does 1/4-28 identify on an aircraft threaded fastener?

   1. A.1/4-inch diameter with 28 threads per inchCorrect answer: A
   2. B.28-inch diameter with 1/4-inch pitch
   3. C.1/4-inch grip with 28-inch total length
   4. D.28 threads with a 1/4-inch head height

   Explanation: The handbook states: "a 1/4-28 thread indicates that a 1⁄4-inch (4⁄16 inch) diameter bolt has 28 threads in 1 inch of its threaded length." Diameter and threads per inch are encoded, not grip, head height or overall thread count.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 7, 7-37, Classification of Threads

6. 6What useful spring property allows a metal to recover after a load is removed, provided its elastic limit has not been exceeded?

   1. A.Brittleness
   2. B.Fusibility
   3. C.Malleability
   4. D.ElasticityCorrect answer: D

   Explanation: The handbook states: "Elasticity is a property that enables a metal to return to its original size and shape when the force that causes the change of shape is removed." Elasticity provides recovery; malleability is permanent shaping, and brittleness or fusibility does not provide spring recovery.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 7, 7-1, Elasticity

7. 7What basic mechanical purpose does a bearing serve in an assembly?

   1. A.To prevent relative motion at the supported joint
   2. B.To transmit motion by deliberately increasing sliding friction
   3. C.To support relative motion with minimum friction and wearCorrect answer: C
   4. D.To remove the need to control shaft alignment

   Explanation: The handbook states: "should permit the other surface to move with a minimum of friction and wear." A bearing supports controlled motion; it neither locks all movement nor removes fit requirements.

   Reference: FAA Aviation Maintenance Technician Handbook—Powerplant — Chapter 1, 1-22, Bearings

8. 8A 20-tooth drive gear turns at 1,200 rpm and meshes with a 60-tooth driven gear. What is the driven speed?

   1. A.3,600 rpm
   2. B.1,800 rpm
   3. C.600 rpm
   4. D.400 rpmCorrect answer: D

   Explanation: The handbook states: "Teeth in Pinion Gear = Speed of Spur Gear Teeth in Spur Gear Speed of Pinion Gear" Speed is inversely proportional to teeth: 1,200 rpm ×20/60=400 rpm. 3,600 reverses the ratio, 600 assumes a 2:1 ratio and 1,800 uses an unrelated factor.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 3, Ratios and Proportions, gear-speed example

9. 9Why is 7 × 19 control cable used where operation over pulleys is frequent?

   1. A.It is extra flexibleCorrect answer: A
   2. B.It is less flexible than a 7 × 7 cable
   3. C.It is designed primarily for rigid compression loads
   4. D.It can operate without controlled cable tension

   Explanation: The handbook states: "This cable is extra flexible and is used in primary control systems and in other places where operation over pulleys is frequent." Extra flexibility suits pulley bending; cable still needs tension and does not function as a compression rod.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 7, 7-72, Cable Construction

10. 10What defect can an excessively deep wire-terminal crimp cause?

    1. A.It may leave the conductor insufficiently retained
    2. B.Cutting or breaking of individual wire strandsCorrect answer: B
    3. C.It may leave an excessive gap between barrel and conductor
    4. D.It may fail to compress the terminal barrel at all

    Explanation: The handbook states: "If the crimp is too deep, it may break or cut individual strands." Excessive compression damages strands; colour and cable classification are not the failure mechanism.

    Reference: FAA Aviation Maintenance Technician Handbook—Airframe — Chapter 9, 9-91, Crimping