Non-Destructive Testing (NDT) Methods Flashcards
7 cards from real ACS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Non-Destructive Testing (NDT) Methods flashcards as text
What type of radiation is used in radiographic inspection of aircraft structural components?
Answer: X-rays or gamma rays
Radiographic inspection uses X-rays (from an X-ray tube) or gamma rays (from radioactive isotopes such as Iridium-192) to penetrate materials and expose a detector or film.
On a radiographic film, a darker area (higher film density) typically indicates what about the inspected material?
Answer: A void, crack, or area of reduced material density allowing more radiation to pass through
Darker areas on radiographic film indicate that more radiation reached the film in those regions, which occurs where material density is lower — such as at voids, cracks, or inclusions of lower-density material.
What is the purpose of a penetrameter (Image Quality Indicator, IQI) in radiographic testing?
Answer: To verify that the radiograph has sufficient sensitivity and quality to detect a defined minimum flaw size
An IQI/penetrameter is placed on the part during exposure; its visibility on the finished radiograph confirms that the technique has adequate sensitivity to detect the minimum required discontinuity size.
Which NDT method is most appropriate for detecting delaminations in a carbon fiber reinforced polymer (CFRP) aircraft panel?
Answer: Ultrasonic testing (pulse-echo or through-transmission)
Ultrasonic testing is the preferred method for detecting delaminations in CFRP composites because delaminations create internal interfaces that reflect ultrasonic energy, and the method works on non-conductive materials.
What is the primary radiation safety concern for technicians performing X-ray radiographic inspection?
Answer: Cumulative exposure to ionizing radiation increasing the risk of biological harm
Ionizing radiation (X-rays and gamma rays) can damage living tissue and DNA; cumulative occupational exposure is regulated by the NRC/OSHA, and technicians must use dosimetry badges and stay within annual dose limits.
What does a bright fluorescent indication under UV (black) light during fluorescent penetrant inspection (FPI) indicate?
Answer: Penetrant has been drawn out of a surface-opening discontinuity, indicating a crack or porosity
A bright fluorescent indication means penetrant trapped in a surface discontinuity has been drawn out by the developer and is fluorescing under UV light, revealing the location and extent of the flaw.
According to FAA AC 43.13-1B, which statement about NDT method selection is correct?
Answer: The NDT method used must be specified in the manufacturer's maintenance manual or approved equivalent data for that inspection
FAA AC 43.13-1B requires that the NDT method and procedure must be those specified in the manufacturer's approved maintenance data; substituting methods without engineering approval is not acceptable.