Airframe Inspection practice questions

Answer: A) Mud, water, salt, and runway debris collect there and attack tubing, fittings, wiring, and structure

Wheel wells are exposed to mud, water, salt and runway debris that get trapped around lines, fittings, electrical parts and structure. That makes them prime spots for corrosion and damage, so they are inspected closely.

• ACorrect. FAA corrosion-control guidance says the wheel well probably takes more punishment than any other area. Mud, water, salt, gravel and debris thrown up from runways collect in crevices, around tubing B-nuts and clamps, and on electrical parts and structure.
• BIncorrect. Wheel wells are normally outside the pressurized area. They are inspected mainly because of exposure to moisture, contamination and debris, not pressure-cycle fatigue.
• CIncorrect. Brake heat can be a concern for tires and nearby components, but routine wheel well inspection is driven by debris, water and corrosion, not by annealing of the structure.
• DIncorrect. Fuel sump drain locations depend on the aircraft design. Fuel contamination checks are not the reason wheel wells are treated as a critical inspection and corrosion area.

Answer: A) A fine crack in the paint at a welded tube cluster joint, with loose mount bolts

Part 43 Appendix D requires checking engine mounts for cracks and looseness. A crack indication at a welded cluster joint, combined with loose attachments, is the finding that needs the closest evaluation.

• ACorrect. Part 43 Appendix D requires checking the engine mount for cracks, looseness of mounting, and looseness of engine to mount. A paint crack at a welded cluster, where stresses concentrate, may mean a fatigue crack in the tube or weld underneath. Together with loose attachments, it must be investigated before further flight.
• BIncorrect. Chipped paint with no corrosion and no crack is a cosmetic finding. It should be touched up to protect the steel, but it does not call for structural evaluation.
• CIncorrect. Paint near the exhaust often darkens from heat. With no cracks and tight attachments, this does not show any of the defects Appendix D lists for the mount.
• DIncorrect. Some compression of the shock mounts is normal in service. If they are within the manufacturer's limits, they do not need corrective action.

Answer: B) Replace the cable

• AIncorrect. This hides damage.
• BCorrect. Internal corrosion means the cable must be replaced.
• CIncorrect. Internal corrosion is not acceptable.
• DIncorrect. This does not fix corrosion.

Answer: C) They convey operating limitations that 14 CFR 91.9 requires the operator to comply with

Required placards and markings show operating limitations. 14 CFR 91.9(a) prohibits operating an aircraft without complying with those limitations, so inspectors make sure the placards and markings are present, correct and legible.

• AIncorrect. 14 CFR 91.9(a) names markings and placards, along with the approved flight manual, as places where operating limitations are specified.
• BIncorrect. Section 91.9(a) applies to any civil aircraft. Required markings and placards are part of the aircraft's certification basis whether or not it is operated for hire.
• CCorrect. Under 91.9(a), no person may operate a civil aircraft without complying with the operating limitations specified in the approved flight manual, markings and placards. Part 43 Appendix D also requires instruments to be checked for marking.
• DIncorrect. Markings and placards are FAA requirements. For example, 14 CFR 25.1541 requires the specified markings and placards, and 91.9(a) requires compliance with the limitations they show.

Answer: A) Corrosion pitting and a small crack in the track lip next to a seat-fitting lock hole

Seat tracks carry the seat loads, so cracks and corrosion at the lock holes are airworthiness defects. Damaged cover strips, a normal lubricant film, and worn paint are cosmetic or routine findings.

• ACorrect. The seat track is the structure that holds the seat to the floor. Corrosion and cracking at the lock holes weaken the track exactly where the seat fitting carries its loads, and a seat could pull free. This is a defect that must be evaluated and repaired.
• BIncorrect. The cover strips are trim pieces that keep debris out of the track. Damaged covers should be replaced, but they carry no seat loads and do not affect the strength of the seat attachment.
• CIncorrect. A light dry-film lubricant is a normal finish that helps fittings move during seat changes. It is not a structural defect.
• DIncorrect. Paint wear from moving seats is cosmetic. It should be watched as a place where corrosion could start, but by itself it does not reduce the strength of the track.

Answer: A) Erosion of the surface from rain, sand, and debris

Composite leading edges face the airflow and take impacts from rain, sand and hail, so erosion of coatings and laminate is the main thing to inspect for. Corrosion types such as intergranular, exfoliation and hydrogen embrittlement affect metals, not composites.

• ACorrect. Leading edges take the direct impact of rain, sand, dust and hail. This wears away protective coatings and then the laminate itself. FAA guidance lists erosion and abrasion as causes of composite deterioration.
• BIncorrect. Intergranular corrosion attacks grain boundaries in metal alloys. Composite fibers and resin have no metal grain structure.
• CIncorrect. Hydrogen embrittlement affects high-strength metals such as steel. It is not a damage mode for cured resin.
• DIncorrect. Exfoliation is a form of corrosion in rolled or extruded metal. Composite plies can delaminate, but they do not corrode by exfoliation.

Answer: B) Cracks and defects

Part 43 Appendix D lists the cowling in the engine and nacelle group as inspected 'for cracks, and defects.' The other choices are criteria the appendix assigns to dampeners, windows, and lines/hoses.

• AIncorrect. Appendix D uses this wording for flexible vibration dampeners in the engine and nacelle group, not for the cowling.
• BCorrect. Appendix D, engine and nacelle group, item (11) reads: 'Cowling—for cracks, and defects.' Worn hinges or latches that do not fully engage are defects under this item.
• CIncorrect. Appendix D uses this wording for windows and windshields in the cabin and cockpit group.
• DIncorrect. Appendix D uses this wording for lines, hoses, and clamps in the engine and nacelle group.

Answer: A) Pulley alignment with the cable, groove wear or roughness, and free rotation of the bearing

Control cable pulleys are inspected for alignment, groove wear or roughness, and free bearing rotation. A misaligned, worn or frozen pulley quickly damages the cable.

• ACorrect. Misalignment, worn or rough grooves, and frozen or flat-spotted bearings all cause cable wear. They are the main conditions checked on pulleys.
• BIncorrect. Hardness testing is not part of a routine pulley inspection. Pulleys are checked visually and by feel for wear, roughness and rotation.
• CIncorrect. Balance matters for propellers and rotor components, not for slow-turning control cable pulleys. Pulleys are not routinely removed for balancing.
• DIncorrect. Many control pulleys are made of phenolic, and pulleys are not bonding paths. Bonding checks apply to bonding jumpers and the components they connect, not to pulley inspection.

Answer: C) Thermography or radiography

• AIncorrect. A ruler cannot detect water.
• BIncorrect. Honeycomb panels are often nonmagnetic.
• CCorrect. These methods show water in cells.
• DIncorrect. Penetrant only finds surface-open defects.

Answer: D) Blocked drains trap water and cause corrosion

• AIncorrect. Skin thickness is measured with gauges.
• BIncorrect. Structure drains are not fuel paths.
• CIncorrect. Drain holes are part of the design.
• DCorrect. Drains must be kept clear.