Maintenance Procedures & Inspection Techniques Flashcards

Liquid penetrant inspection is capable of detecting which type of discontinuity?

Answer: Discontinuities open to the surface

Penetrant must enter the flaw through a surface opening, so only surface-open discontinuities are revealed.

Which material CANNOT be inspected using magnetic particle inspection?

Answer: 2024-T3 aluminum alloy

Magnetic particle inspection works only on ferromagnetic materials, and aluminum is non-magnetic.

Eddy current inspection is especially well suited for which task?

Answer: Detecting cracks around fastener holes in aluminum skins

Eddy current detects surface and near-surface flaws in electrically conductive materials, such as cracks at fastener holes.

Why is a couplant applied between an ultrasonic transducer and the test part?

Answer: To exclude air so sound energy transmits into the part

Air reflects nearly all ultrasonic energy, so a couplant fills the gap and allows sound to enter the part.

When current is passed directly through a part (a head shot), which defects are best detected?

Answer: Defects running parallel to the part's long axis

A head shot creates circular magnetization, which reveals defects lying parallel to the current flow, along the part axis.

In radiographic inspection, what is the purpose of a penetrameter (image quality indicator)?

Answer: To verify the sensitivity and quality of the radiograph

The penetrameter shows whether the radiograph has enough sensitivity to reveal flaws of a given size.

What must be done to a steel part after magnetic particle inspection, before it is returned to service?

Answer: Demagnetize it

Residual magnetism can attract metal particles and affect nearby instruments, so the part must be demagnetized.