Airframe 3 Flashcards
What components are in a vapor cycle cooling?
Receiver dryer
Evaporator
Compressor
Condenser
Expansion valve
Why is oil added to a vapor cycle Freon system?
To seal and lubricate the compressor
What is the function of ventilating air in a combustion heater?
It transports heat from the heater into the cabin AND prevents combustion gases from entering the cabin if the combustion chamber develops a crack
Who is authorized to apply the range markings to an instrument dial face?
Manufacturer or certified instrument repair station
What does a yellow arc on an instrument dial indicate?
Caution
Why are slippage marks used on instruments glass covers?
To indicate glass rotation in the bezel. If the glass rotates, the range markings will be off.
What references should be consulted to determine the proper range markings for aircraft instruments?
Aircraft maintenance manual
Aircraft flight manual
Type certificate data sheet
Aircraft specifications
When range markings are placed on an instrument glass what precaution must be taken?
The glass must be marked for slippage indication
What is required after replacement of components connected to a pitot static system?
A leak test
What is the meaning of swinging a compass?
Correcting for deviations by adjusting the compensating magnets
Name at least two items that should be looked for during an inspection of a magnetic compass
Security of attachment
Correct readings at various headings
The bowl should be full and without bubbles or discoloration
The scale should be readable
Moving parts should work easily
In what way do magnetic fields generated by electrical equipment and steel parts in the airplane affect a magnetic compass?
They deflect the compass from correct alignment with the earths magnetic field
What quantity is accurately measured by capacitance type fuel, quantity indicating system?
The mass of the fuel
What are the basic auto pilot components?
Sensing elements (gyros)
Output elements (servos)
Command elements (flight controller)
Computing elements (computer and amplifier)
What are the sensing elements of an auto pilot system?
Attitude and indicator gyro
Directional Gyro indicator
Turn and bank coordinator gyro
Altitude control sensor
What are the actuating elements of an auto pilot system?
Servos that operate the control surfaces
What is the function of the servo’s in an auto pilot system?
To actuate the flight controls
What is the most common communication system in use?
VHF band 118.0 to 136.975 Mhz
What is VOR equipment used for?
Navigation
What are the components of a typical VOR system?
Receiver
Visual indicator
Frequency selector
Antennas
Power supply
What is an ADF?
Automatic direction finder
Why are two antennas or a single multi element antenna usually required for an ILS system?
One is for the localizer and the other is for the glide-slope receivers
What information does a glideslope radio beam provide?
Vertical guidance for correct angle of descent
What is a DME?
Distance measuring equipment
Where should DME antennas be located?
Generally, on the bottom of the fuselage in a location that is not blocked by the wing
What powers an emergency locator transmitter (ELT)?
An internal battery
What is one method used to monitor the output signal during an ELT test?
A VHF communications receiver turned to 121.5 Mhz
What time of day should you perform the maintenance tests of an installed ELT?
During the first five minutes after the hour for no more than three sweeps. At any other time tests should be coordinated with the nearest control tower of flight service station
How often does the ATC transponder require certification?
Every 24 calendar months
How may the determination be made to replace or recharge the batteries in an ELT even though the set operates?
An expiration date for replacing or recharging the batteries is marked on the outside of the transmitter and entered in the aircraft maintenance record
What are the basic components of a radio communication system?
Microphone
Transmitter
Transmitting and receiving antennas
Receiver
Speakers or headphones
Describe the shape and location of a transponder antenna
Either a short blade or a short wire with a ball and located on the top of the fuselage
What is the purpose of a bonding jumper from the radio shock mount to the air frame?
To provide low impedance ground return
Describe the procedure used to route coaxial cables from an antenna to a receiver
The cable should be routed separately from other wires and supported every 2 feet. Benz should be 10 times the cable diameter.
Why should you wait a period of time after fueling before checking fuel sumps?
To allow time for water and sediment to settle to the drain point
What should be done with old gaskets and seals when replacing fuel systems components?
Old gaskets and seals should be replaced by new ones
What method may be used to check a fuel tank for leaks after a weld repair has been performed?
Pressurize the tank with 1/2 to 3 psi air pressure and use a soapy solution to detect any leaks
What are drip gauges and sight gauges?
Underwing bayonet type fuel gauges
Is it possible for a fuel system to develop a leak that has no visible evidence such as a stain or spot and if so, how?
Yes. An internal component such as a valve or pump could develop a leak.
Name some advantages to a single point fueling system
Fueling time is reduced
Risk of contamination is reduced
Risk of fire is reduced
Eliminate damage to the aircraft skin
What controls the output voltage of an alternator?
The GCU (generator control unit)
What factors are considered when selecting wire size for electrical power?
Permissible voltage drop
System voltage
Wire length
Current wire will carry
Whether the load is continuous or intermittent
What should be done to a conduit when fittings are not used?
It should be deburred to prevent insulation damage
How many terminal lugs can be put on a single terminal strip stud in an aircraft?
4
When do DC motors draw several times their rated current?
When starting
When is a circuit breaker designed to open?
When an overload or circuit fault exists, and before the wire emits smoke
What type of circuit breaker should not be used in aircraft?
Automatic reset type circuit breakers
What could cause an AC electric motor to run too fast?
Excessive applied voltage or shorted field windings
How is the output voltage of an alternator controlled?
By varying the field current that excites the alternator
What instruments are used to monitor electrical system loads?
Ammeters and voltmeters
