Generals

Question 1

What constitutes a capacitor?

Answer 1

Two conductors separated by an insulator.

Question 2

What is the purpose of a capacitor?

Answer 2

It stores electrical energy in electrostatic fields.

Question 3

What is the basic unit of capacitance?

Answer 3

The farad.

Question 4

Why should electrolytic capacitors not be used in an AC circuit?

Answer 4

They are polarized. An electrolytic capacitor will pass current of one polarity, but will block current of the opposite polarity.

Question 5

What is a fuselage station number?

Answer 5

The distance in inches from the datum, measured along the longitudinal axis of the fuselage.

Question 6

What is a butt line?

Answer 6

A reference line to the right or left of the center line of the aircraft.

Question 7

Of what material are most low-pressure rigid fluid lines made?

Answer 7

1100-1/2 hard or 3003-1/2 hard aluminum alloy tubing.

Question 8

Is the size of a rigid fluid line determined by its inside or its outside diameter?

Answer 8

By its outside diameter.

Question 9

What is the difference between the flare angle for aircraft and automotive fittings?

Answer 9

Aircraft fittings have a 37° flare angle and automotive fittings use 45°.

Question 10

Where are quick-disconnect fluid line couplings normally used in an aircraft hydraulic system?

Answer 10

In the lines that connect the engine-driven pump into the hydraulic system.

Question 11

Is the size of a flexible hose determined by its inside or its outside diameter?

Answer 11

By its inside diameter.

Question 12

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

Answer 12

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

Question 13

How is steel annealed?

Answer 13

Steel is heated to just above its upper critical temperature until it reaches a uniform temperature throughout, then it is allowed to cool very slowly in the oven.

Question 14

How is steel hardened?

Answer 14

Steel is heated to its critical temperature and quenched in water, brine, or oil.

Question 15

What is meant by tempering steel?

Answer 15

The steel is first hardened; then some of the hardness is removed to relieve some of the internal stresses and brittleness.

Question 16

What is meant by case hardening?

Answer 16

The surface of the metal is hardened by the infusion of carbon or aluminum nitride. The interior of the metal remains strong and tough.

Question 17

What are two methods of case hardening?

Answer 17

Carburizing and nitriding.

Question 18

How is steel nitrided?

Answer 18

The steel part is heated in a retort in which there is an atmosphere of ammonia. Aluminum combines with the nitrogen to form an extremely hard aluminum nitride on the surface of the steel.

Question 19

What is the method of solution heat treatment of an aluminum alloy?

Answer 19

The metal is hardened by heating it in a furnace to a specified temperature and immediately quenching it in water. It is soft when it is removed from the quench, but as it ages it regains its hardness.

Question 20

What is the method of precipitation heat treating of an aluminum alloy?

Answer 20

The metal is heated and quenched, then it is returned to the oven and heated to a lower temperature. It is held at this temperature for a specified time, then removed from the oven and allowed to cool in still air. This increases the strength and hardness of the metal.

Question 21

What is another name for precipitation heat treatment?

Answer 21

Artificial aging.

Question 22

Identify and explain the differences between heat-treated and non-heat-treated aluminum alloys.

Answer 22

Heat-treated aluminum alloy designations are normally followed with a -T, followed by a number (1-10) that designates the type of heat treat. A common aircraft aluminum alloy is 2024-T3. Heat-treated aluminum is stronger than non-heat-treated aluminum.

Question 23

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

Answer 23

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 24

What kind of rope is best to tie down an aircraft?

Answer 24

Nylon or polypropylene.

Question 25

What kind of knot is used for securing an airplane with a rope?

Answer 25

Bowline.

Question 26

When starting an aircraft engine equipped with a float carburetor, in what position should the carburetor heat control be placed?

Answer 26

In the Cold position.

Question 27

What is meant by a liquid lock in the cylinder of an aircraft engine, and how is it cleared?

Answer 27

Oil accumulates in the cylinders below the center line of the engine and prevents the piston from moving to the top of its stroke. To clear a liquid lock, remove one of the spark plugs and turn the engine crankshaft until all of the oil is forced out of the cylinder.

Question 28

What is the procedure if a hung start occurs when starting a turbojet engine?

Answer 28

Terminate the starting operation and find the reason the engine would not accelerate as it should.

Question 29

How far ahead of an idling turbojet engine does the danger area extend?

Answer 29

25 feet.

Question 30

What are the control tower light signals that may be used when taxiing or towing an aircraft, and what are their meanings?

Answer 30

a. Flashing green - Cleared to taxi. b. Steady red - Stop. c. Flashing red - Taxi clear of runway in use. d. Flashing white - Return to starting point. e. Alternating red and green - Exercise extreme caution.

Question 31

What is meant by detonation in an aircraft reciprocating engine?

Answer 31

Detonation is an uncontrolled burning of the fuel in the cylinder of an engine. It is an explosion, rather than a smooth burning.

Question 32

What causes corrosion?

Answer 32

Corrosion is a natural phenomenon that attacks metal by chemical or electrochemical action and converts it into a metallic compound, such as an oxide, hydroxide, or sulfate. Corrosion occurs because of the tendency for metals to return to their natural state. Noble metals like gold and platinum do not corrode since they are chemically uncombined in their natural state. Conditions that can cause corrosion to develop or worsen are moisture, oxygen, chemicals, and temperature.

Question 33

What must be done to a piece of aluminum alloy to remove surface corrosion and to treat the metal to prevent further corrosion?

Answer 33

Remove the corrosion residue with a bristle brush or a nylon scrubber. Neutralize the surface with chromic acid or with some type of conversion coating. Protect the surface from further corrosion with a coat of paint.

Question 34

How may rust be removed from a highly stressed metal part?

Answer 34

By glass bead blasting, by careful polishing with mild abrasive paper, or by using fine buffing compound on a cloth buffing wheel.

Question 35

What tools are proper for removing corrosion from aluminum alloy?

Answer 35

Aluminum wool or aluminum wire brushes. Severe corrosion can be removed with a rotary file.

Question 36

What type of device is used to remove surface corrosion from a piece of magnesium alloy?

Answer 36

A stiff hog-bristle brush.

Question 37

What record must be made of a major repair to an aircraft structure?

Answer 37

An FAA Form 337 must be completed for the repair, and a record must be made in the aircraft maintenance records referencing the Form 337 by its date.

Question 38

How many copies must be made of a Form 337 after a major airframe repair?

Answer 38

At least two copies must be made. The original signed form goes to the aircraft owner, and a copy goes to the FAA district office.

Question 39

How long must major repair or alteration records be kept?

Answer 39

A copy of all Form 337s must be kept for the life of the aircraft.

Question 40

What is a malfunction and defect report?

Answer 40

Malfunction and Defect Reports (FAA Form 8010-4) are a voluntary reporting mechanism to report unusual problems or weakness not associated with expected wear.

Question 41

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

Answer 41

Fluorescent or visual dye penetrant.

Question 42

What is the principle upon which ultrasonic inspection is based?

Answer 42

Any fault within a 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 43

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

Answer 43

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.