Materials and Processes

Question 1

Which steel alloy is noted for its toughness and is most commonly use for aircraft structure, frame, members, engine mounts, landing gear parts, and other structural parts?

Answer 1

Chrome Molybdenum Steel

Question 2

How is work hardening metal obtained?

Answer 2

Buy cold working the metal

Question 3

Which case hardening process is accomplished on steel alloys after heat treating to produce a wear resistant surface on engine parts, such as crankshafts?

Answer 3

Nitrating

Question 4

What portable hardness is commonly use for testing, aluminum, alloys, copper, brass, or other relatively soft materials?

Answer 4

Bracol tester

Question 5

What class of thread are aircraft bolts commonly manufactured?

Answer 5

Class three medium fit

Question 6

How may AN standard steel bolts be identified?

Answer 6

Code markings on the bolt heads

Question 7

What is the grip length of a bolt?

Answer 7

It is the unthreaded portion of the bolt

Question 8

What is the difference between a general purpose bolt between a close tolerance bolt?

Answer 8

Close tolerance bolts are machined to be more accurate than General bolts

Question 9

Where should self locking nuts not be used?

Answer 9

Joints were either the nut or bolt or subject to rotation

Question 10

How can the recommended torque for a bolt or nut be determined when torque values are not called out and the maintenance procedures?

Answer 10

Use the information contained in the standard torque table, such as the AC 43.13–1B.

Question 11

What do the markings on the heads of solid shake rivets indicate?

Answer 11

The material of which they are made and their strength

Question 12

What may be accomplished to prevent heat treated aluminum alloy rivets from becoming hard after the quenching process?

Answer 12

Store them in a freezer at temperatures lower than 37°F and they will remain soft for several days

Question 13

What type of cable is commonly used in primary control systems?

Answer 13

Extra flexible 7x19 stainless steel cable

Question 14

When performing a penetrant inspection, what happens to the applied penetrant after removal from a part that is cracked?

Answer 14

The penetrant liquid enters the crack and remains there in order to make the crack visible after developer is applied

Question 15

What is the procedure for performing a dye penetrant inspection?

Answer 15

Clean the surface, apply penetrate, remove the penetrate with emulsifier or cleaner, dry, apply developer, and interpret results

Question 16

What in NDT methods could be used for detecting surface cracks in aluminum fittings?

Answer 16

Dye penetrant, x-ray, ultrasonic, eddy current, visual inspection

Question 17

Which NDT method can be performed without removing the surface coatings, such as primer, paint, and anodized films?

Answer 17

Eddy current

Question 18

Name some tools that are commonly used to assist in making visual inspections of welds

Answer 18

A magnifying glass, flashlight, mirror, and possibly a borescope

Question 19

What does the magnetic particle inspection process consist of?

Answer 19

The basic process consist of magnetizing a part, and then applying ferromagnetic particles to the surface area to be inspected. If a defect is present, the particles will form a pattern on the surface.

Question 20

What are the penetration requirements for a fillet weld?

Answer 20

Should be 25 to 50% of the thickness of the base metal

Question 21

What width should welding bead have and what should be the depth penetration in a butt weld?

Answer 21

Should be 3 to 5 times the thickness of the base metal and 100% penetration

Question 22

What type of precision measuring instruments can be used to measure the outside dimensions of aircraft parts?

Answer 22

Outside micrometers and Vernier Calipers

Question 23

Why should a micrometer be periodically calibrated?

Answer 23

To ensure it’s accuracy

Question 24

Why does alloy steel that is responsible to heat treatment usually less suitable for welding?

Answer 24

Because of its tendency to become brittle and lose its ductility in the welded area

Question 25

What is the main difference between thermoplastic and thermosetting resins?

Answer 25

Thermoplastic – soften by heat, and will become hard when cool down
Thermosetting – does not soften with heat. It will char and burn rather than melt.

Question 26

What are some of the purposes for which thermoplastic and thermosetting resins are commonly used in modern aircraft?

Answer 26

Thermal plastic is used in plexiglass, such as windows and windshields. Thermosetting is a matrix material in composite structures.

Question 27

Name one material commonly used as the reinforcing component in structural composite laminates?

Answer 27

Kevlar, fiberglass, and graphite

Question 28

Name one substance commonly used as the matrix material and structural composite laminate

Answer 28

Polyester resin, or epoxy resin

Question 29

Name one advantage of using pre-preg materials over non-pre-preg materials in the construction or repair

Answer 29

Pre-Preg materials have the proper amount of matrix, and the reinforcing fibers are completely and evenly permeated with the matrix. The matrix has the correct proportions of resin and hardener. And it is a low cost.

Question 30

What are the undesirable characteristics of a cold weld?

Answer 30

Improper penetration with rough and irregular cold laps not feathered into the base metal