Generals Flashcards
What constitutes a capacitor?
Two conductors separated by an insulator.
What is the purpose of a capacitor?
It stores electrical energy in electrostatic fields.
What is the basic unit of capacitance?
The farad.
Why should electrolytic capacitors not be used in an AC circuit?
They are polarized. An electrolytic capacitor will pass current of one polarity, but will block current of the opposite polarity.
What is a fuselage station number?
The distance in inches from the datum, measured along the longitudinal axis of the fuselage.
What is a butt line?
A reference line to the right or left of the center line of the aircraft.
Of what material are most low-pressure rigid fluid lines made?
1100-1/2 hard or 3003-1/2 hard aluminum alloy tubing.
Is the size of a rigid fluid line determined by its inside or its outside diameter?
By its outside diameter.
What is the difference between the flare angle for aircraft and automotive fittings?
Aircraft fittings have a 37° flare angle and automotive fittings use 45°.
Where are quick-disconnect fluid line couplings normally used in an aircraft hydraulic system?
In the lines that connect the engine-driven pump into the hydraulic system.
Is the size of a flexible hose determined by its inside or its outside diameter?
By its inside diameter.
Why is a piece of steel tempered after it has been hardened?
When steel is hardened, it becomes brittle. Tempering removes some of this brittleness.
How is steel annealed?
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.
How is steel hardened?
Steel is heated to its critical temperature and quenched in water, brine, or oil.
What is meant by tempering steel?
The steel is first hardened; then some of the hardness is removed to relieve some of the internal stresses and brittleness.
What is meant by case hardening?
The surface of the metal is hardened by the infusion of carbon or aluminum nitride. The interior of the metal remains strong and tough.
What are two methods of case hardening?
Carburizing and nitriding.
How is steel nitrided?
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.
What is the method of solution heat treatment of an aluminum alloy?
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.
What is the method of precipitation heat treating of an aluminum alloy?
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.
What is another name for precipitation heat treatment?
Artificial aging.
Identify and explain the differences between heat-treated and non-heat-treated aluminum alloys.
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.
Why is it important that a piece of aluminum alloy be quenched immediately after it is removed from the heat treating oven?
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.
What kind of rope is best to tie down an aircraft?
Nylon or polypropylene.
What kind of knot is used for securing an airplane with a rope?
Bowline.
When starting an aircraft engine equipped with a float carburetor, in what position should the carburetor heat control be placed?
In the Cold position.
What is meant by a liquid lock in the cylinder of an aircraft engine, and how is it cleared?
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.
What is the procedure if a hung start occurs when starting a turbojet engine?
Terminate the starting operation and find the reason the engine would not accelerate as it should.
How far ahead of an idling turbojet engine does the danger area extend?
25 feet.
What are the control tower light signals that may be used when taxiing or towing an aircraft, and what are their meanings?
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.
What is meant by detonation in an aircraft reciprocating engine?
Detonation is an uncontrolled burning of the fuel in the cylinder of an engine. It is an explosion, rather than a smooth burning.
What causes corrosion?
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.
What must be done to a piece of aluminum alloy to remove surface corrosion and to treat the metal to prevent further corrosion?
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.
How may rust be removed from a highly stressed metal part?
By glass bead blasting, by careful polishing with mild abrasive paper, or by using fine buffing compound on a cloth buffing wheel.
What tools are proper for removing corrosion from aluminum alloy?
Aluminum wool or aluminum wire brushes. Severe corrosion can be removed with a rotary file.
What type of device is used to remove surface corrosion from a piece of magnesium alloy?
A stiff hog-bristle brush.
What record must be made of a major repair to an aircraft structure?
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.
How many copies must be made of a Form 337 after a major airframe repair?
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.
How long must major repair or alteration records be kept?
A copy of all Form 337s must be kept for the life of the aircraft.
What is a malfunction and defect report?
Malfunction and Defect Reports (FAA Form 8010-4) are a voluntary reporting mechanism to report unusual problems or weakness not associated with expected wear.
What is the proper type of nondestructive inspection to use for locating surface cracks in an aluminum alloy casting or forging?
Fluorescent or visual dye penetrant.
What is the principle upon which ultrasonic inspection is based?
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.
What is the procedure when making a dye penetrant inspection of a part?
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.
