Airframe o&p asa test areas

What is one of the most important considerations when selecting materials for a

sheet metal repair?

The repair material must duplicate the strength of the original structure.

For maximum strength of a formed sheet metal fitting, should the bend be made

along or across the grain of the metal?

Across the grain.

What determines the minimum bend radius that can be used when forming a

sheet metal structural fitting?

The alloy, the metal thickness, and its hardness.

What is meant by the neutral axis in a sheet of metal?

A plane within the metal that neither stretches nor shrinks when the metal is being bent.

What is a mold line In the development of a flat pattern for a formed metal part?

An extension of the flat sides beyond the radius.

What is the bend tangent line?

A line in a flat pattern layout at which the bend starts.

What is meant by setback?

The distance the jaws of a brake must be set back from the mold line to form a bend.

What is meant by bend allowance?

The actual amount of metal in a bend. It is the distance between the bend tangent lines

in a flat pattern layout.

What Is a sight line?

A line drawn on a flat pattern layout within the bend allowance that is one bend radius

from the bend tangent line. When the sight line is directly below the nose of the radius

bar on the brake, the bend will start at the bend tangent line.

What Is the main function of throatless shears in an aircraft sheet metal shop?

Throatless shears are used to cut mild carbon steel up to 10-gauge, and stainless steel

up to 12-gauge. They can be used to cut irregular curves in the metal.

What kind of metal forming is done by a sllp roll former?

Simple curves with a large radius.

What kind of metal forming Is done by bumping?

Compound curves in sheet metal.

When forming a curved angle, what must be done to the flanges?

The flanges must be stretched for a convex curve and shrunk for a concave curve.

When hand-forming a piece of sheet metal that has a concave curve, should the

forming be started In the center of the curve, or at Its edges?

Start at the edges and work toward the center.

What Is meant by a joggle In a piece of sheet metal?

A joggle is a small offset near the edge of a piece of sheet metal that allows the sheet to

overlap another piece of metal.

What is another name for GTA welding?

TIG welding.

What Is used as the electrode in GTA welding?

A small-diameter tungsten wire.

What are three types of power that can be used for GTA welding?

DC-straight polarity, DC-reverse polarity, and 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.

What kind of repair can be made to a small damage of the core materiat 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.

Does the FAA require that a checklist be used when conducting an annual or a

100-hour inspection?

Yes, according to 14 CFR §43.15(c)(1).

For how long must the record of a 100-hour Inspection be retained In the aircraft

maintenance records?

For one year, or until the next 100-hour inspection is completed.

For how long must the record of the current status of life-limited parts of an

engine be retained?

This is part of the permanent records and it must be retained and transferred with the

aircraft when it is sold.

What would cause the warning horn to sound when the throttles are pulled back,

reducing the engine power for landing?

The warning horn will sound if any of the landing gears are not down and locked.

What is indicated by e red light In the landing gear position-indication portion of

the annunciator panel?

The red light indicates that the 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?

Three green lights are used on most aircraft to indicate that all three landing gears are

down and locked.

Is it best to store new tires vertically or horizontally?

Vertically.

What Is the most important maintenance procedure for aircraft tires?

Keep them properly inflated.

What should be used to remove oil from a tire?

Mild soap and warm water.

Where do you find the proper Inflation pressure for an aircraft tire?

In the aircraft service manual.

Why should aircraft tire pressure be rechecked after tt has been installed for

about 24 hours with no load applied?

The tire will stretch and the pressure will drop. The proper pressure must be restored.

What causes an aircraft tire to wear more on the shoulders than in the center of

the tread?

Operating the tire in an underinflated condition.

What causes an aircraft tire to wear more in the center of the tread than on the

shoulders?

Operating the tire in an overinflated condition.

What should be done to an aircraft tire if the sidewalls are weather-checked

enough to expose the cord?

The tire should be scrapped.

What should be done with a tire that was on a wheel which was overheated

enough to melt the fusible plug in the wheel?

The tire should be scrapped.

Why are the cabins of most turbine-powered aircraft pressurized?

These aircraft fly at suoh high altitudes that supplemental oxygen would be needed for

the occupants if the cabins were not pressurized.

Where does the pressurizing air come from on most turbine-powered aircraft?

From air bled from one of the engine compressors.

Where does the pressurizing air come from on most smaller reciprocating-

engine-powered aircraft?

From the engine turbocharger.

What determines the amount of pressurization that an aircraft can use?

The structural strength of the aircraft cabin.

What is meant by the isobaric mode of cabin pressurization?

The isobaric mode of cabin pressurization is the mode that keeps the cabin altitude

constant as the aircraft changes its flight altitude.

What is meant by the constant differential mode of cabin pressurization?

After the pressure in the aircraft cabin reaches the maximum value allowed by structural

considerations, the constant differential mode of operation holds the pressure inside the

cabin a constant amount above the outside air pressure.

What are the three fundamental pressure-sensing mechanisms used in aircraft

instrument systems?

The Bourdon tube, the diaphragm or bellows, and the solid-state sensing device.

What basic mechanism is used to measure oil, fuel, and oxygen pressures?

The Bourdon tube.

What mechanical means is used to measure pressure In an airspeed indicator?

A diaphragm.

A failure of an airspeed indicator needle to move is likely caused by what

problem?

A blockage in the pitot head will prevent the creation of a differential pressure.

What kind of antenna is used for the ATC transponder?

A UHF stub antenna.

What is the preferred location for the ATC transponder antenna?

On the center line of the belly of the aircraft as far from any other antenna as is practical.

What are the three basic types of antennas used In aviation?

Dipole antenna, Marconi antenna, and loop antenna.

What type of antenna are most aircraft VHF communication antennas?

Marconi antennas.

How do static wicks aid the aircraft communication radios?

Static wicks aid in the dissipation of static that builds up on the aircraft. Built-up static can

cause radio receiver interference caused by corona discharge emitted from the aircraft

as a result of precipitation static.

What must be done after a fuel system strainer has been cleaned or replaced?

The system must be tested for leaks by pressurizing the system with the boost pump, if

one is used.

What must be done if the sump drains sample shows traces of jet fuel?

The fuel system must be drained and flushed out with the proper grade of aviation

gasoline.

What size generator must be used In an aircraft electrical system if the connected

electrical load is 30 amps, and there is no way of monitoring the generator

output?

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 the frame of the generator. This is done by passing

battery current through the field coils in the direction it normally flows when the generator

is operating.

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.

What is the composition of 60/40 solder?

60% tin and 40% lead.

What is the difference between soldering and brazing?

Soldering is a method of joining metal parts with a molten nonferrous alloy that melts at a

temperature below 800°F. Brazing is essentially the same except the brazing alloy melts

at a temperature higher than 800°F but lower than the melting temperature of the metal

on which it is used.

Why must acid-core solder never be used on electrical wire?

The acid causes the wire to corrode.

What determines the strength of a soldered joint?

The mechanical connection of the joint, not the solder.

Why are solderless splices usually better than soldered splices in the wiring of an

aircraft electrical system?

Soldered joints are usually stiff, and vibration can harden the wire and cause i1 to break.

Solderless splices are designed to keep the joint flexible so vibration cannot cause the

wire to break.

What is meant by a trip-free circuit breaker?

A circuit breaker that cannot be closed while a fault exists, regardless of the position of

the operating handle.

What is meant by a slow-blow fuse?

A fuse that will allow more current than its rating to flow for a short period of time, but will

open the circuit if more than its rated current continues to flow.

What is the function of a fuse or circuit breaker in an aircraft electrical circuit?

It protects the wiring from an excess of current. It will open the circuit if enough current

flows to heat the wire.

What are two principles upon which circuit breakers operate?

Magnetic circuit breakers open a circuit when the current creates a strong enough

magnetic field. Thermal circuit breakers open a circuit when the current causes enough

heat.

What circuit in an aircraft electrical system is not required to have a circuit

protective device?

The main circuit for starter motors, used during starting only.

Is an automatic-reset circuit breaker approved for aircraft electrical circuits?

No, a manual operation is needed to restore service after the circuit breaker has tripped.

How does a vibrator-type voltage regulator maintain a constant voltage?

When the voltage rises above the desired value, an electromagnetic relay opens and

inserts a resistor in the generator field circuit, decreasing the field current and lowering

the generator output voltage.

What two components are normally housed with a vibrator voltage regulator In a

single-unit generator control?

A current limiter and a reverse-current cutout relay.

How can you determine the state of charge of a CO2 fire extinguisher?

By its weight.

How can you determine the state of charge of a freon fire extinguisher container?

By the pressure shown on the built-in gauge.

How does the ambient temperature affect the pressure shown on the pressure

gauge on a freon fire extinguisher? {AM.II.M.K7)

The higher the temperature, the higher the pressure.

How can you determine whether or not a built-In fire extinguishing system has

been discharged?

By checking the blowout plugs on the outside of the aircraft near the extinguisher agent

bottles.

What Is Indicated if the red disc In a built-in fire extinguishing system Is

blown out?

The agent bottle has been discharged because of an overheat condition.

What is indicated if the yellow disc in a built-In fire extinguishing system is blown

out?

The agent bottle has been discharged by the flight crew actuating the Bottle Discharge

switch.