Aircraft Materials, Hardware, & Processes

Question 1

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

Answer 1

Zyglo or dye penetrant.

Question 2

Explain the procedure to use when making a dye penetrant inspection of a part.

Answer 2

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

Question 3

Explain the procedure to use when making a magnetic particle inspection of a part.

Answer 3

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 4

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

Answer 4

Eddy current inspection.

Question 5

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

Answer 5

X-ray inspection.

Question 6

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

Answer 6

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 7

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

Answer 7

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

Question 8

Why is it important that a piece of aluminum alloy be quenched immediately after it is removed from the heat-treating oven?

Answer 8

Any delay in quenching aluminum alloy after it is removed from the oven will allow the grain structure to grow enough that intergranular corrosion is likely to form in the metal.

Question 9

Explain the way a steel structure is normalized after it has been welded.

Answer 9

Heat the steel structure to a temperature above its critical temperature and allow it to cool in still air.

Question 10

Why is a piece of steel tempered after it has been hardened?

Answer 10

When steel is hardened, it becomes brittle and tempering removes some of this brittleness.

Question 11

What is meant by an icebox rivet?

Answer 11

A rivet made of 2017 or 2024 aluminum alloy. These rivets are heat-treated and quenched, then stored in a subfreezing ice box until they are ready to be used.
The cold storage delays the hardening of the rivet.

Question 12

What type of loading should be avoided when using a self-locking nut on an aircraft bolt?

Answer 12

A self-locking nut should not be used for any application where there are any rotational forces applied to the nut or to the bolt.

Question 13

What determines the correct grip length of a bolt used in an aircraft structure?

Answer 13

The grip length of the bolt should be the same as the combined thicknesses of the materials being held by the bolt.

Question 14

How tight should the nut be installed on a clevis bolt that is used to attach a cable fitting to a control surface horn?

Answer 14

The nut on a clevis bolt should not be tight enough to prevent the clevis bolt turning in the cable fitting and the horn.

Question 15

Why is it very important that the surface of a piece of clad aluminum alloy not be scratched?

Answer 15

The pure aluminum used for the cladding is noncor-rosive, but the aluminum alloy below the cladding is susceptible to corrosion. If the cladding is scratched through, corrosion could form.

Question 16

What determines the size of tip that is to be used when gas welding steel?

Answer 16

The thickness of the material being welded. The size of the tip orifice determines the amount of flame produced, and thus the amount of heat that is put into the metal.

Question 17

How is the welding flux removed from a piece of aluminum that has been gas welded?

Answer 17

It should be removed by scrubbing it with hot water and a bristle brush.

Question 18

What must be done to a welded joint if it must be rewelded?

Answer 18

All traces of the old weld must be removed so the new weld will penetrate the base metal.

Question 19

What kind of measuring instrument is used to measure the runout of an aircraft engine crankshaft?

Answer 19

A dial indicator.

Question 20

What measuring instruments are used to measure the fit between a rocker arm shaft and its bushing?

Answer 20

The outside diameter of the shaft is measured with a micrometer caliper. The inside of the bushing is measured with a telescoping gauge and the same micrometer caliper.

Question 21

What is the smallest size cable that is allowed to be used in the primary control system of an aircraft?

Answer 21

1/8-inch diameter.

Question 22

What type of control cable must be used when pulleys are used to change the direction of cable travel?

Answer 22

Extra-flexible cable (7 × 19).

Question 23

Explain the way a piece of aluminum alloy is heat-treated.

Answer 23

The aluminum is heated in an oven to the proper temperature for a specified time; then it is removed and quenched in water.

Question 24

What is meant by precipitation heat treatment of a piece of aluminum alloy?

Answer 24

After a piece of aluminum has been solution heat-treated, it is held at a specified elevated temperature for a period of time. Precipitation heat-treating is also called artificial aging.

Question 25

How does filiform corrosion usually appear on an aircraft structure?

Answer 25

As thread-like lines of puffiness under a film of polyurethane or other dense finish system topcoats.