AMT General Aircraft Maintenance Knowledge 3 — Questions and Answers
Question 1: What is the purpose of an 'overhaul' as defined in 14 CFR Part 43, Appendix D?
- Restoring an item to a serviceable condition by cleaning, inspecting, and replacing worn parts
- Restoring an item to a like-new condition using FAA-approved data and within new-part tolerances (Correct answer)
- Inspecting an item against manufacturer limits without part replacement
- Updating an item to the latest approved configuration
Correct answer: Restoring an item to a like-new condition using FAA-approved data and within new-part tolerances
An overhaul restores a component to new-part tolerances using FAA-approved data, verifying all dimensions are within limits specified for new parts.
Question 2: A technician discovers a crack in an aircraft skin panel. What is the FIRST action before determining repair procedure?
- Stop-drill the crack immediately
- Consult the aircraft's Structural Repair Manual (SRM) for approved repair data (Correct answer)
- Apply a doubler patch as an interim repair
- File an FAA Service Difficulty Report
Correct answer: Consult the aircraft's Structural Repair Manual (SRM) for approved repair data
Before any repair action, the technician must consult approved data — the SRM or FAA-approved equivalent — to determine the correct inspection and repair procedure.
Question 3: Which rivet is recommended when riveting dissimilar metals that cannot be anodized after assembly to prevent galvanic corrosion?
- AN470 AD rivet (2117-T4 alloy)
- AN426 DD rivet (2024-T4 alloy)
- Monel rivet (Correct answer)
- AN470 A rivet (1100 alloy)
Correct answer: Monel rivet
Monel rivets are used where galvanic compatibility is critical, particularly when joining stainless steel or other metals that would create severe galvanic couples with aluminum rivets.
Question 4: According to FAA AC 43.13-1B, what is the minimum edge distance for a rivet hole measured from the center of the hole to the edge of the sheet?
- 1.5 times the rivet diameter
- 2 times the rivet diameter (Correct answer)
- 2.5 times the rivet diameter
- 3 times the rivet diameter
Correct answer: 2 times the rivet diameter
AC 43.13-1B specifies a minimum edge distance of 2D (twice the rivet diameter) from the rivet centerline to the nearest sheet edge.
Question 5: What condition is indicated when a hydraulic system's relief valve opens frequently during normal operations?
- The fluid is over-filtered and bypassing the actuators
- The system pressure is set too low relative to demand
- The pump output exceeds the system's demand or a downstream component is blocked (Correct answer)
- The reservoir is over-filled
Correct answer: The pump output exceeds the system's demand or a downstream component is blocked
Frequent relief valve opening indicates the pump is producing more pressure than the system can use, often because a component is blocked or the pump is oversized for the demand.
Question 6: What does the term 'mean aerodynamic chord' (MAC) represent in aircraft weight and balance?
- The average chord length of a tapered or swept wing, used as a reference for CG limits expressed as a percentage (Correct answer)
- The chord at the wing root
- The chord at the wing tip
- The chord at the widest point of the fuselage
Correct answer: The average chord length of a tapered or swept wing, used as a reference for CG limits expressed as a percentage
MAC is the chord of an imaginary rectangular wing with the same lift and center-of-pressure characteristics as the actual wing, used to express CG location as a percentage for tapered or swept wings.
Question 7: An aircraft reciprocating engine exhibits low oil pressure at idle but normal pressure at cruise RPM. The MOST likely cause is:
- A clogged oil filter bypassing unfiltered oil
- Worn engine bearings causing excessive oil clearance (Correct answer)
- A stuck-closed oil pressure relief valve
- Low oil temperature causing excessive viscosity
Correct answer: Worn engine bearings causing excessive oil clearance
Worn main or rod bearings increase oil clearance, allowing oil to leak past at low pump output (idle), while higher pump output at cruise maintains adequate pressure.
AMT General Aircraft Maintenance Knowledge 3
What is the purpose of an 'overhaul' as defined in 14 CFR Part 43, Appendix D?