Inspection Concepts and Techniques

Question 1

What are different types of micrometer calipers?

Answer 1

Outside micrometer, inside micrometer, depth micrometer, and thread micrometer.

Question 2

How often should torque wrenches be calibrated?

Answer 2

Depending on the tool, some are calibrated every 6 months, while others are calibrated every 12 months.

Question 3

What is the proper type of nondestructive inspection to use for locating surface cracks in an aluminum alloy casting or forging?

Answer 3

Fluorescent or visual dye penetrant.

Question 4

What is the principle upon which ultrasonic inspection is based?

Answer 4

Any fault within material will change the material’s resonant frequency. Comparing the resonant frequency of a known sound material with the material under test will indicate the presence of a fault.

Question 5

What is the procedure when making a dye penetrant inspection of a part?

Answer 5

Clean the part thoroughly, apply the penetrant, and allow it to soak for the recommended dwell time. Remove all of the penetrant from the surface and apply the developer.

Question 6

In addition to 100-hour and annual inspections, where would an aircraft operator find the approved inspection programs for an aircraft?

Answer 6

In the manufacturer’s maintenance manual and Instructions for continued Airworthiness (ICA).

Question 7

What inspection method would be most appropriate for checking a nonferrous metal part for intergranular corrosion?

Answer 7

Eddy current inspection.

Question 8

What inspection method would be most appropriate for checking the internal structure of an airplane wing for corrosion?

Answer 8

X-ray inspection.

Question 9

What inspection method would be most appropriate for checking a steel landing gear component for stress cracks?

Answer 9

Magnetic particle inspection.

Question 10

What type of inspection is best suited for detecting a fault withing a piece of nonferrous metal?

Answer 10

Ultrasonic inspection.

Question 11

Why is it important that all parts be thoroughly cleaned before they are inspected by the dye penetrant method?

Answer 11

Any grease or dirt in a fault will keep the penetrant from seeping into the fault.

Question 12

What is the procedure to use when performing a magnetic particle inspection of a part?

Answer 12

Thoroughly clean the part, magnetize it as directed by the appropriate service manual, flow the indicating medium over the surface, and inspect it under a “black light”. When the inspection is complete, thoroughly demagnetize the part.

Question 13

Why is it necessary to magnetize a part both circularly and longitudinally when inspecting a steel part by the magnetic particle method?

Answer 13

To detect faults that extend across as well as lengthwise within the part.

Question 14

Does circular magnetization detect faults that are across or lengthwise to the part?

Answer 14

Lengthwise.

Question 15

Why is it important that all engine parts that have been inspected by the magnetic particle method be completely demagnetized?

Answer 15

If the parts are not completely demagnetized, they will attract steel particles that are produced by engine wear and will cause damage to bearing surfaces.

Question 16

What is the principle of eddy inspection?

Answer 16

A current is induced into the metal being tested by a test probe. The amount of induced current is determined by the conductivity, mass, and permeability of the material, and the presence of any faults or voids.

Question 17

Why is it important to demagnetize a component following a magnetic particle inspection?

Answer 17

To prevent magnetized parts from attracting filings, grindings, chips, or other steel particles, which can cause scoring, damage, and premature wear.

Question 18

What are the dangers of the incorrect use of precision micrometers and calipers?

Answer 18

Incorrect measurement of close tolerance components can lead to failure of critical parts and assemblies.

Question 19

Why is calibration of precision measuring equipment important?

Answer 19

Measuring equipment that is out of calibration can result in incorrect measurements, which can lead to component and system failure.

Question 20

What are the risks of not using the correct inspection techniques?

Answer 20

Incorrect inspection techniques will lead to the aircraft or component not being inspected in accordance with the manufacturer’s specifications, which can lead to failure of the inspected item.

Question 21

What precautions should be taken when using a multimeter to measure resistance, voltage, and current?

Answer 21

Inocrrect use of a multimeter can cause damage to the multimeter and/or result in incorrect conclusions regarding the circuit or component being tested. When used as an ohmmeter, the component being measured must be isolated (disconnected) from the circuit. If the multimeter is set for measuring current, and the leads are place across any voltage drop, the meter can be damaged. A thorough understanding of the circuit being tested is critical for proper trouble shooting.