Airframe Flashcards
What is another name for GTA welding?
TIG welding
What is used as the electrode in GTA welding?
tungsten wire
What are the three types of power that can be used for GTA
DC straight polarity
DC reverse polarity
AC
Which type of power provides the greatest heat and deepest penetration in GTA welding?
DC straight polarity
Which type of power is used for GTA welding aluminum and magnesium?
DC reverse polarity
Should a riveted joint fail in shear or in bearing?
Shear
Most important consideration when selecting materials for a sheet metal repair?
Material must duplicate the strength of the original structure
why should aluminum alloy rivets be driven with as few blows as is practical?
prevents work hardening the rivet and making them harder to drive
what determines whether a piece of sheet metal should be dimpled or countersunk when installing flush rivets?
Thickness of the sheet.
(countersinking should be done only when the thickness of the sheet is greater than the thickness of the rivet head.)
what should be done to protect a riveted joint between aluminum alloy and magnesium alloy from corrosion.
coat surface and dip rivets in corrosion inhibiting primer.
(drive them while wet)
what is the purpose of the beehive spring on a rivet gun?
holds the rivet set in the gun and allows the gun to vibrate the set
what must be done to an aircraft fuel tank before it can be repaired by welding?
purge gas fumes for 30 minutes by:
steam
soaking in hot water
filling with nitrogen
filling with C02
when drilling out rivets on an airplane or drilling holes for a repair, what precaution should be taken?
don’t allow drill to enter space behind the structure
what are two advantages of laminated construction over riveted sheet metal?
light weight
&
rigidity
what are two popular types of CORE material used in laminated structure?
foam & honeycomb
what are two popular types of MATRIX material used in laminated structures?
polyester & epoxy resins
what are the two parts of a polyester matrix material?
resin & catalyst
what are the two parts of an epoxy matrix material?
Resin & hardener
what are the three materials that may be used to reinforce the matrix material for aircraft structure?
fiberglass
Kevlar
graphite
what is meant by a uni-directional fabric?
major fibers run in same direction
what is meant by ribbon direction of a honeycomb material?
the direction in a piece of honeycomb material that is parallel to the length of the strips that make up its core
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?
potted compound repair
how do you grind the point of a twist drill that is to be used for drilling transparent acrylic material?
cutting edge to a ZERO rake angle
angle of the tip 140
what is a warp clock in a structural repair manual?
an alignment indicator for orientation of the plies
what are two types of repair to a damaged honeycomb core composite material?
room temperature cure repair
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?
signed & dated list of all the discrepancies that keep the plane 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?
14 CFR 43.11
under what conditions can an aircraft be operated with a 100 hour overdue?
no more than 10 hours after inspection is due for the purpose of flying to a place for inspection
for how long can an aircraft be operated if a 100 hour is overdue?
10 hours, which must be subtracted from when the next inspection is due
under what condition can an aircraft due for an annual inspection be operated?
only with a special flight permit
what certification is required for a mechanic to be able to approve an aircraft for return to service after a 100 hour inspection?
A&P
what determines whether or not an aircraft must be given a 100 hour inspection?
if they carry persons for hire
&
flight instruction for hire
what is the difference between an annual inspection and a 100 hour?
the inspections are identical.
only an I.A can do an annual
what certification is required for a mechanic to conduct an annual inspection and approve the aircraft for return to service
inspection authorization
(IA)
what is a progressive inspection?
Same as an annual, but performed on a schedule not requiring the plane to go out of service
what certification is required for a mechanic to conduct a progressive inspection?
Inspection authorization
(IA)
where can you find the requirements for inspecting the altimeter and static systems of an aircraft operated under instrument flight rules?
14 CFR part 43 appendix E
where can you find the requirements for inspecting the ATC transponder?
14 CFR part 43 appendix F
what items must be inspected on a helicopter in accordance with the instructions for continued airworthiness?
1 drive shafts,
2 main rotor
3 main rotor center section
4 auxiliary rotor
5 transmission gear box,
where would an aviation mechanic find required special inspections?
aircraft maintenance manual
what are the three basic brake actuating systems?
power break system
(only uses hydraulic system)
independent system
(doesn’t use hydraulic system)
booster system
(hydraulic system intermittently)
what would cause the warning horn to sound when the throttles are pulled back reducing the engine power for landing?
if landing gears are not down and locked
what is indicated by a red light in the landing gear position indication portion of the annunciator panel?
landing gear is not in a safe condition for landing
what information is given to a pilot to indicate that all of the landing gears are down and locked?
3 green lights
is a Chevron seal a one way or two way seal?
one way
which side of a Chevron seal should the pressure be applied?
the open side
is an O-ring seal a one way or two way seal?
2 way
how can you be sure of getting an O-ring made of the correct material for a specific hydraulic component?
correct part number
on which side of an O-ring should the back up ring be placed?
on the side away from the source of pressure
what should be done to the sharp edges of threads and actuator pistons when installing O-rings?
cover with paper
what are the two main gases that make up our atmosphere
oxygen
nitrogen
what is used to check an oxygen system for leaks?
leak detector liquid that is a form of non-oily soap
why must fittings in an oxygen system not be tightened to stop a leak when there is pressure on the system?
the tube is expanded slightly when pressurized
what kind of gaseous oxygen must be used to service an aircraft oxygen system?
aviators breathing oxygen
(no moisture)
what identification must be stamped on an oxygen bottle carried in an aircraft?
indentification DOT 3AA or 3HT
date of manufacture
date of hydrostatic tests
to what pressure and how often should DOT 3AA oxygen cylinders be hydrostatically tested?
5/3 of their working pressure every 3 years
to what pressure and how often should DOT 3HT oxygen cylinders be hydrostatically tested, and when should the be retired from service?
tested to 3083 psi every three years
retired after 15 years or 4380 pressurizations
what kind of lubricant can be used for installing fitting in an oxygen system component?
Teflon tape
or
special water base lubricant
what is used to check for leaks after replacing a fitting in an oxygen system?
special leak detector liquid that is non-oily soap
what cleaning solutions can be used to clean parts used in an oxygen system?
anhydrous ethyl alcohol
isopropyl alcohol,
freon
what may be used to dry components in an oxygen system after the have been cleaned?
water pumped dry nitrogen
what may be used to purge the lines in an oxygen system after it has been opened for servicing?
water pumped dry nitrogen
what must be done before any maintenance can be done on an oxygen system?
the oxygen supply must be turned off at the bottle valve
how is the heat removed from an aircraft cabin with the vapor cycle air conditioning system?
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 condensor
what produces the cool air in the vapor cycle air conditioning system?
cabin heat is absorbed by the refrigerant in the evaporator, the air that leaves the evaporator is cool
what is used as the refrigerant in a vapor cycle air conditioning system?
freon type liquid
(refrigerant 12)
or
more environmentally friendly R-134a
what is the state of the refrigerant as it leaves the compressor?
high pressure gas
what is the state of the refrigerant as it leaves the condenser?
high pressure liquid
what is the state of the refrigerant as it leaves the thermostatic expansion valve?
low pressure liquid
what is the state of the refrigerant as it leaves the evaporator?
low pressure vapor
how is the compressor lubricated?
refrigeration oil is mixed with the refrigerant
what is the function of the thermostatic expansion valve?
meters just enough liquid refrigerant into the evaporator that all of it will be evaporated when it leaves the evaporator coils
how is refrigerant 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?
cool
how is a vapor cycle cooling system checked for refrigerant leaks?
hold probe of an electronic leak detector below any suspected leak, tone will sound
what safety equipment should be worn when charging a vapor cycle cooling system?
safety face shield
what are the two types of air conditioning systems that may be installed on an aircraft?
air cycle
vapor cycle
why is a fuel jettisoning or dump system required for some aircraft?
to lower gross weight to allowable landing weight
what is used as the sensor in the fuel tank for an electronic type fuel quantity indicating system?
tubular capacitors
extend across the fuel tank from top to bottom
what is the principle upon which the electronic type fuel quantity indicating system operates?
tubular capacitors change their capacitance as fuel level changes.
what is used as a sensor in the fuel tank for the older resistance type fuel quantity indicating system?
Variable resistor
arm is moved by float
what is the purpose of a drip gauge in the fuel tank of a large aircraft?
you can check fuel level from the bottom of the tank
when must the fuel quantity indicating system indicate zero?
during level flight when fuel in tank is equal to unusable fuel supply
what size generator must be used in an aircraft electrical system if the connected electrical load is 30 amp, and there is no way of monitoring the generator output?
the load must be no more that 80% of the rated output.
37.5 (practically a 40 amp generator would be used)
what is meant by flashing the field of a generator?
restoring residual magnetism to the frame of the generator. By passing current through the coils in the direction it normally flows when operating.
what is meant by paralleling the generators in a multi engine aircraft?
adjusting voltage regulators so all the generators share the load equally
what are the three types of voltage regulators used with aircraft generators?
vibrator
carbon pile
solid state
what is meant by a trip free circuit breaker?
If there’s a fault in the system the circuit breaker won’t close
what is meant by slow blow fuse?
fuse will allow more current that its rating to flow for a short period of time
what is the function of a fuse or circuit breaker in an aircraft electrical circuit?
protects wiring from excess current. Will open the circuit if enough current flows to heat the wire
what are two principles upon which circuit breakers operate?
magnetic circuit breakers
thermal circuit breakers
what circuit in an aircraft electrical system is not required to have a circuit protective device?
main circuit for starter motors used for starting only
is an automatic reset circuit breaker approved for aircraft electrical circuits?
No. Manual only.
how does a vibrator type voltage regulator maintain a constant voltage?
when voltage rises above desired value, electromagnetic relay opens and inserts a resistor in the generator field circuit
what two components are normally housed with a vibrator voltage regulator in a single unit generator control?
current limiter
reverse current cutout relay
what two frequencies does the emergency locator transmitter operate?
121.5 megahertz
243.0 megahertz
where is the ELT transmitter normally located?
In the tail or as far aft as possible
how often should ELT batteries be replaced or recharged?
after 1 hour of cumulative use
at battery expiration date
when 50% of their useful life has expired
how can you know when an ELT batter must be replaced?
date marked on the outside of the transmitter
how often must ELTs be inspected for proper installation, battery corrosion, operation of the controls and sensor, and the presence of the radiated signal?
every 12 calendar months
what causes and ELT to actuate?
and inertia switch that detects an impact parallel to the longitudinal axis of the aircraft
how is an ELT tested to determine that its working?
actuate the test switch and listen on 121.5 or 243.0 MHz. during the first 5 minutes of the hour. Only operate for 3 sweeps
