ARF Orals Codes Flashcards
Should a riveted joint fail in shear or in bearing?
It should fail in shear. The rivets should shear before the sheet tears at the rivet holes.
What is done to cotton and linen fabric to protect it from mildew?
The first coat of dope used on cotton and linen fabric has a mildewcide mixed in it.
Does rejuvenator restore strength to the fabric?
No, it only restores resilience to the finish.
What kind of repair can be made to a small damage of the core material and one face sheet of a piece of aluminum alloy honeycomb structure?
A potted compound repair.
How do you grind the point of a twist drill that is to be used for drilling transparent acrylic material?
The cutting edge should be dubbed off to a zero rake angle, and the included angle of the tip should be ground to 140 degrees.
What is a warp clock in a structural repair manual?
An alignment indicator to show the orientation of the plies of a composite material. The ply direction is shown in relation to a reference direction.
What are two types of repair to a damaged honeycomb core composite material?
Room-temperature cure repair and hot-bond repair.
If a mechanic gives a 100-hour inspection to an aircraft that proves to be unairworthy, what must the mechanic give the owner or operator of the aircraft?
A signed and dated list of all of the discrepancies that keep the aircraft from being airworthy.
Where can you find the recommended statement to use for recording the approval or disapproval of an aircraft for return to service after a 100-hour inspection?
In 14 CFR §43.11.
Under what conditions can an aircraft be operated with a 100-hour inspection overdue?
The aircraft can be operated for no more than 10 hours after an inspection is due for the purpose of flying it to a place where the inspection can be performed.
For how long can an aircraft be operated if a 100-hour inspection is overdue?
For no more than 10 hours. The time beyond the 100 hours must be subtracted from the time before the next inspection is due.
Under what conditions can an aircraft that is due for an annual inspection be operated?
It can only be flown when a special flight permit is issued.
What certification is required for a mechanic to be able to approve an aircraft for return to service after a 100-hour inspection?
An Aviation Mechanic certificate with Airframe and Powerplant ratings.
What determines whether or not an aircraft must be given a 100-hour inspection?
Aircraft that carry persons for hire and aircraft that are used for flight instruction for hire must be given 100-hour inspections.
What is the difference between an annual inspection and a 100-hour inspection?
The inspections themselves are identical. An annual inspection can be conducted only by an A&P mechanic who holds an Inspection Authorization, while a 100-hour inspection can be performed by an A&P mechanic without an IA.
What certification is required for a mechanic to conduct an annual inspection and approve the aircraft for return to service after the inspection?
An Aviation Mechanic certificate with Airframe and Powerplant ratings and an Inspection Authorization.
What is a progressive inspection?
An inspection of the same level as an annual inspection but approved by the FAA to be performed on a schedule that does not require the aircraft to be out of service for the time necessary to perform the entire inspection all at once.
What certification is required for a mechanic to conduct a progressive inspection?
An Aviation Mechanic certificate with Airframe and Powerplant ratings and an Inspection Authorization.
Where can you find the requirements for inspecting the altimeter and static systems of aircraft operated under instrument flight rules?
In 14 CFR Part 43, Appendix E.
Where can you find the requirements for inspecting the ATC transponder that is installed in an aircraft?
In 14 CFR Part 43, Appendix F.
What items must be inspected on a helicopter in accordance with the Instructions for Continued Airworthiness?
The drive shafts or similar systems, the main rotor transmission gear box, the main rotor and center section, and the auxiliary rotor.
Where can you find instructions for hoisting an aircraft to replace wheels with floats?
In the aircraft maintenance manual.
What are the two basic types of hydraulic fluid used in modern aircraft?
Mineral base fluid and phosphate ester base fluid.
Does the main hydraulic pump take its fluid from the bottom of the reservoir, or from a standpipe?
The main pump normally takes its fluid from a standpipe, while the emergency pump takes its fluid from the bottom of the reservoir.
If a break in the system should allow the main pump to pump all of its fluid overboard, there will still be enough fluid in the reservoir to allow the emergency system to extend the landing gear and actuate the brakes.
Why are some hydraulic reservoirs pressurized?
Pressurization ensures that fluid will be supplied to the inlet of the pumps at high altitude where there is not enough atmospheric pressure to do this.
What are two ways aircraft hydraulic reservoirs may be pressurized?
By an aspirator in the fluid return line or by bleed air from one of the engine compressors.
What is used to flush a hydraulic system that uses Skydrol hydraulic fluid?
Trichlorethylene or the solvent recommended by the aircraft manufacturer.
What is used to flush a hydraulic system that uses mineral base hydraulic fluid?
Naphtha, varsol, or Stoddard solvent.
Where can you find the type of hydraulic fluid required for a particular aircraft?
In the maintenance manual for the aircraft. This information is also on a placard on the system reservoir.
What type of pump is a gear pump considered?
A gear pump is a constant displacement, high pressure pump.
What type of pump is a piston pump with a variable cam plate considered?
A piston pump with a variable cam is a variable displacement pump with constant pressure.
How is the heat removed from an aircraft cabin with a vapor-cycle air conditioning system?
The cabin heat is absorbed by the refrigerant in the evaporator, then carried outside the aircraft where it is given up to the outside air in the condenser.
What produces the cool air in a vapor-cycle air conditioning system?
Warm cabin air is blown across the evaporator, where its heat is transferred into the refrigerant. The air that leaves the evaporator is cool.
What is used as the refrigerant in a vapor-cycle air conditioning system?
R-134a, a Freon-type liquid refrigerant.
What is the state of the refrigerant as it leaves the compressor?
It is a high-pressure gas.
What is the state of the refrigerant as it leaves the condenser?
It is a high-pressure liquid.
What is the state of the refrigerant as it leaves the thermostatic expansion valve?
It is a low-pressure liquid.
What is the state of the refrigerant as it leaves the evaporator?
It is a low-pressure vapor.
How is the compressor lubricated?
Refrigeration oil is mixed with the refrigerant and it circulates through the compressor and the entire system.
What is the function of the thermostatic expansion valve?
It meters just enough liquid refrigerant into the evaporator that all of it will be evaporated by the time it leaves the evaporator coils
How is refrigerant put into the system?
It is put into the system through service valves on the low side of the system using a manifold gauge set.
How should the components in the low side of a properly operating vapor-cycle cooling system feel?
They should feel cool.
How is a vapor-cycle cooling system checked for refrigerant leaks?
Hold the probe of an electronic leak detector below any suspect fitting or component. If there is a leak, the tone of the sound produced by the detector will change.
What safety equipment should be worn when charging a vapor-cycle cooling system?
A safety face shield that protects the entire face.
What are two types of air conditioning systems that may be installed on an aircraft?
Air-cycle systems and vapor-cycle systems.
What is the basic purpose of an autopilot?
It frees the human pilot from continuously having to fly the aircraft, and flies with a high degree of precision. It also couples with various electronic navigational aids.
What are the basic subsystems of an automatic flight control system?
Command, error-sensing, correction, and follow-up.
What type of device is normally used in the error-sensing subsystem?
Gyros.
What are three types of servos that are used in the correction subsystem?
Hydraulic, pneumatic, and electric.
What is the purpose of the follow-up subsystem in an autopilot?
It stops the control movement when the surface has deflected the proper amount for the signal sent by the error sensor.
Where are fuel system strainers located?
One strainer is located in the outlet to the tank, and the main strainer is located in the fuel line between the outlet of the fuel tank and the inlet to the fuel metering device.
Why do the fuel strainers used on some turbine-engine aircraft have a warning device?
Strainers clog because ice forms on the filter element. The flight crew can route the fuel through a fuel heater to melt the ice.
How does water appear in the fuel drained from the tank sumps?
Water appears as a clear globule in the bottom of the container used to collect the fuel drained from the sumps.
Why must an aircraft fuel valve have a detent in its operating mechanism?
The detent gives the pilot a positive indication by feel when the selector valve is in the full ON and full OFF position.
What must be done before a fuel selector valve can be removed from an aircraft?
The tank to which the valve is connected must be drained or otherwise isolated.
What must be done after a fuel valve is replaced?
The fuel system must be checked for leaks.
Why is a fuel jettisoning or dump system required for some aircraft?
A fuel dump system is installed on most large aircraft and allows the flight crew to jettison, or dump, fuel to lower the gross weight of the aircraft to its allowable landing weight.
What size generator must be used in an aircraft electrical system if the connected electrical load is 30 amps?
When monitoring is not practical, the total continuously connected electrical load must be no more than 80% of the rated generator output. This would require a generator with a rating of 37.5 amps. Practically, a 40-amp generator would be installed.
What is meant by ‘flashing’ the field of a generator?
Restoring the residual magnetism to frame of generator
What is meant by paralleling the generators in a multi-engine aircraft?
Adjusting the voltage regulators so all the generators share the electrical load equally.
What are three types of voltage regulators used with aircraft generators?
Vibrator-type, carbon-pile type, and solid state-type.
How many electrical phases are in aircraft alternators?
Three.
What is the advantage of using AC power over DC power?
AC voltages can be stepped up to higher voltages, which means that current goes down and smaller wires can be used to save weight. The voltage is stepped back down at the point of use.
What is the frequency of AC voltage used in aircraft?
400 Hz.
How is ice kept from forming on the pitot tube of an airplane?
Pitot tubes are heated by electric current flowing through heater elements built into them.
How is ice prevented from forming on the windshield of modern jet transport airplanes?
The windshield has a heater element embedded in it. Electric current heats the windshield and keeps ice from forming on it.
What type of fire extinguishing agent is best for both cabin fires and engine fires?
Halon 1301.
What types of fire extinguishing agents should not be used in aircraft cabins or flight decks?
CO2, dry chemicals, or specialized dry powders.
What is a major disadvantage of ‘CB’ fire extinguishing agent for extinguishing aircraft fires?
It is corrosive to aluminum and magnesium.
Why is carbon tetrachloride not recommended as a fire extinguishing agent?
Carbon tetrachloride produces phosgene, a deadly gas, when it is exposed to flames.
What is used as a fire extinguishing agent in most of the high-rate discharge systems installed in aircraft?
One of the halogenated hydrocarbons, such as Halon 1301, pressurized with nitrogen.
Where can you find correct part number for the fuel quantity sensor to be installed in an aircraft fuel tank?
Illustrated Parts Catalog for the aircraft
