FAA Aviation Mechanic Airframe (AMA)Airframe StructuresHard
A technician needs to inspect an assembled wing structure for internal corrosion and hidden cracks without disassembly. The chosen method must be able to penetrate through multiple layers of material and produce a shadow image on film for interpretation. Which nondestructive inspection method should be used?
- AEddy current inspection
- BRadiographic (X-ray) inspection
- CUltrasonic inspection
- DLiquid penetrant inspection
Show answer & explanationAnswer & explanation
Correct answer: B. Radiographic (X-ray) inspection
Radiographic (X-ray) inspection uses penetrating radiation that passes through the structure and exposes film on the opposite side, producing a shadow image that reveals internal flaws such as corrosion, cracks, or foreign objects hidden within assembled structures without disassembly. Strict radiation safety precautions are required.
Why the other options are wrong
- A. Eddy current is limited to surface and near-surface flaws in conductive materials, not deep internal imaging.
- C. Ultrasonic inspection detects internal flaws using sound waves and a display readout, not a film shadow image.
- D. Liquid penetrant only detects flaws open to the surface, not internal or hidden damage.
Radiographic (X-ray) Inspection
An NDI method using X-ray or gamma radiation to penetrate a structure and expose film, producing a shadow image that reveals internal flaws such as corrosion, cracks, or foreign objects without disassembly.
- Uses penetrating radiation (X-ray/gamma)
- Produces a film-based shadow image
- Detects internal flaws in multi-layer/assembled structures
- Requires strict radiation safety precautions and trained personnel
Memory trick: X-ray sees through walls like a superhero, leaving a shadow picture on film.