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Preservatives on main landing gear wheels

Aviation Mechanic General (AMG) practice question 19 of 31 on Cleaning and Corrosion Control. ACS element AM.I.G.K9 · difficulty: recall. Want to answer it in a timed quiz? Use the Aviation Mechanic General (AMG) practice mode.

Question bank updated 2026-09-22

QUESTIONWhy can preservative compounds not be used on some main landing gear wheels?

  1. APreservatives dissolve the magnesium wheel alloy
  2. BHeat generated by braking action
  3. CThe compounds attract gravel and mud
Show the answer and explanation

Correct answer: B. Heat generated by braking action

  • A — incorrect The handbook gives brake heat, not a chemical reaction with magnesium, as the reason.
  • B — correct The handbook states that, due to heat generated by braking action, preservatives cannot be used on some main landing gear wheels.
  • C — incorrect Mud and gravel are hazards of the wheel well area in general; they are not cited as the reason preservatives are excluded from wheels.

BACKGROUND

Selecting a corrosion preventive compound (CPC) depends on the part and its service conditions. In the wheel well and landing gear area, complete coverage is hard to maintain, and a partially applied preservative can mask corrosion. The handbook also notes that heat generated by braking action means preservatives cannot be used on some main landing gear wheels. Elsewhere it prescribes water-displacing lubricants for piano hinges and hard-film preservative coatings on seaplane and amphibian engine surfaces.

STUDY TIP

When choosing a CPC, ask what the part experiences in service (heat, motion, moisture); the handbook's choices follow from those conditions.

KEY POINTS

  • Brake heat prevents preservative use on some main gear wheels
  • Piano hinges get water-displacing lubricants
  • Seaplane engine surfaces keep hard-film preservative coatings

SOURCES

  • FAA-H-8083-30B ch08 "Wheel Well and Landing Gear"
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SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-30B Aviation Maintenance Technician Handbook – General, 14 CFR part 43 and part 65. Regulations and handbooks are revised; confirm details against the current edition.