Airframe inspection is the ACS area where regulation meets technique. The questions ask what a 100-hour or annual inspection has to cover, where the results are recorded, and, for the larger half, which nondestructive method will actually find a given defect. Every AMTprep question tagged to AM.II.D comes with a rationale and a handbook reference. If you can keep four inspection methods straight and remember that a proper visual inspection is a method in its own right with its own rules, this is one of the more reliable areas to pick up points.
AM.II.D draws on the inspection material in FAA-H-8083-31 plus the inspection rules in 14 CFR Part 43. On the paperwork side, expect the checklist question: a person performing a 100-hour or annual inspection must use a checklist that covers at least the scope and detail of Appendix D to 14 CFR Part 43, or a manufacturer's equivalent. Expect a second question on where the results go, which is a maintenance record entry stating the type of inspection, the date, the aircraft time in service, and the signature and certificate number of the person approving or disapproving the aircraft for return to service. The technique half starts with the visual inspection, which finds most defects. Questions here reward the mundane answer: clean the area, light it properly, and use a mirror and flashlight to see surfaces you cannot look at directly, with a magnifier for a suspected crack. Then the four methods. Liquid or dye penetrant finds only discontinuities that break the surface and cannot be used on porous material. Magnetic particle finds surface and slightly subsurface discontinuities, but only in ferromagnetic parts such as steel bolts, gear components and engine parts, and the part must be demagnetized afterward. Eddy current works on any conductive material, sees surface and near-surface cracks, and can find cracks in second-layer structure around fasteners with little disassembly. Ultrasonic passes sound through the part to find internal flaws and thickness loss. Symptom questions close the area out: smoking or dark smudges around rivet heads mean working, loose fasteners, and a fine network of surface cracks in an acrylic transparency is crazing.
ACS AM.II.D is tested on the FAA Airframe written test, one of 1,748 ACS-tagged questions in the Airframe bank. Every question tagged to this area carries a worked rationale and its FAA handbook reference, so you can drill the code itself rather than the whole test.
What document serves as the basis for the items checked during a 100-hour or annual inspection of an aircraft?
When performing a visual inspection of an aircraft structure, adequate lighting and the use of a mirror and flashlight are important because they help the technician
A magnetic particle inspection method can be used to detect surface and subsurface discontinuities in
A limitation of the dye penetrant inspection method is that it can only detect defects that
Eddy current inspection of aircraft structure is particularly useful because it can
When inspecting a sheet metal structure, a row of fasteners that shows smoking or a dark smudge pattern around the heads usually indicates
After completing a required 100-hour or annual inspection, the technician must record the results in the
ACS code: AM.II.D
Correct answer: The scope and detail listed in 14 CFR Part 43, Appendix D
Rationale: Annual and 100-hour inspections must cover the scope and detail of items listed in 14 CFR Part 43, Appendix D, unless an approved inspection program is used. The Airframe Handbook stresses that this appendix defines the minimum checklist content for a complete airframe inspection.
ACS code: AM.II.D
Correct answer: detect defects in areas that are not directly visible
Rationale: Visual inspection is the most widely used method, and the handbook notes that mirrors, flashlights, and magnifiers extend the inspector's reach into hidden or shadowed areas. These aids reveal cracks and damage that would otherwise be missed, but they do not measure depth or alloy.
ACS code: AM.II.D
Correct answer: ferromagnetic materials such as steel
Rationale: Magnetic particle inspection relies on magnetizing the part, so it only works on ferromagnetic materials like iron and steel. The handbook notes nonmagnetic materials such as aluminum, magnesium, and composites cannot be inspected by this method.
ACS code: AM.II.D
Correct answer: are open to the surface of the part
Rationale: Penetrant inspection works by capillary action drawing fluid into a defect that breaks the surface; if a crack is not open to the surface, the penetrant cannot enter it. The handbook therefore limits this method to detecting surface discontinuities only.
ACS code: AM.II.D
Correct answer: detect cracks without removing surface coatings
Rationale: Eddy current testing induces circulating currents in conductive material; a crack disrupts those currents and changes the probe reading. The handbook notes it can find surface and near-surface cracks, including around fastener holes, often without removing paint.
ACS code: AM.II.D
Correct answer: working or loose rivets in the joint
Rationale: A dark 'smoking rivet' trail of aluminum oxide powder around a rivet head is caused by the rivet working in its hole, abrading metal as the joint flexes. The handbook identifies this as a sign of loose or working rivets requiring further inspection and repair.
ACS code: AM.II.D
Correct answer: aircraft maintenance records
Rationale: Upon completing an inspection, the person must make an entry in the aircraft maintenance records describing the inspection and its findings, as required by Part 43. The handbook reinforces that proper recordkeeping is part of completing the inspection.
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