AIRFRAME PREPWARE
(Refer to Figure 4.) The amount of material required to make the 90° bend is
0.3436 inch.
(Refer to Figure 1.) Which of the rivets shown will accurately fit the conical depression made by a 100° countersink?
1
(Refer to Figure 11.) An AN flared tube fitting is referred to in which picture?
1
(Refer to Figure 16.) Which of the antennas shown is a typical DME antenna?
1
(Refer to Figure 2.) Select the preferred drawing for proper countersinking.
1
(Refer to Figure 12.) Which illustration(s) show(s) the correct spiral for teflon backup rings?
1 and 3.
A potted compound repair on honeycomb can usually be made on damages less than
1 inch in diameter.
How much clearance from the seat bottom is required when installing radio equipment under a seat?
1 inch with the seat occupied and subjected to maximum downward seat spring deflection.
A typical large transport aircraft fuel manifold system allows how many of the following? 1. All tanks can be serviced through a single connection. 2. Any engine can be fed from any tank. 3. All engines can be fed from all tanks simultaneously. 4. A damaged tank can be isolated from the rest of the fuel system.
1, 2, 3, and 4.
A sheet metal repair is to be made using two pieces of 0.040-inch aluminum riveted together. All rivet holes are drilled for 3/32-inch rivets. The length of the rivets to be used will be
1/4 inch.
The dimensions of an MS20430AD-4-8 rivet are
1/8 inch in diameter and 1/2 inch long.
The flat layout or blank length of a piece of metal from which a simple L-shaped bracket 3 inches by 1 inch is to be bent depends upon the radius of the desired bend. The bracket which will require the greatest amount of material is one which has a bend radius of
1/8 inch.
What is the smallest size cable that may be used in aircraft primary control systems?
1/8 inch.
The maximum time a 100-hour inspection may be extended is
10 hours.
When bending coaxial cable, the bend radius should be at least
10 times the diameter of the cable.
In installations where the ammeter is in the generator or alternator lead, and the regulator system does not limit the maximum current that the generator or alternator can deliver, the ammeter can be redlined at what percent of the generator or alternator rating?
100
The maximum altitude loss permitted during an unpressurized aircraft instrument static pressure system integrity check is
100 feet in 1 minute.
When a butt-welded joint is visually inspected for penetration, the penetration should be
100 percent of the thickness of the base metal.
Using a hand pump, pressure of 100 psi has been built up in a hydraulic system. The hand pump piston is 1 inch in diameter. A 1/2-inch line connects the hand pump to an actuating cylinder 2 inches in diameter. What is the pressure in the line between the hand pump and the actuator?
100 psi.
When repairing puncture-type damage to a metal-faced laminated honeycomb panel, the edges of the doubler should be tapered to
100 times the thickness of the metal.
A certificated mechanic may perform
100-hour inspections of instruments.
The maximum deviation (during level flight) permitted in a compensated magnetic direction indicator installed on an aircraft certificated under 14 CFR Part 23 is
10°.
(Refer to Figure 9.) When the outside air temperature is 80°F, select the acceptable 3/16 cable tension range.
117 pounds minimum, 143 pounds maximum.
What should be the included angle of a twist drill for hard metal?
118°.
A single-lap sheet splice is to be used to repair a section of damaged aluminum skin. If a double row of 1/8-inch rivets is used, the minimum allowable overlap will be
13/16 inch.
Where is fuselage station No. 137 located?
137 inches aft of the zero or fixed reference line.
Where would you find the recommended statement for recording the approval or disapproval for return to service of an aircraft after a 100-hour or annual inspection?
14 CFR Part 43.
Where would you find the operating conditions that make a 100-hour inspection mandatory?
14 CFR Part 91.
A fuel jettison system is required under certain conditions if the maximum takeoff weight exceeds the maximum landing weight. What regulations cover the requirements of fuel jettisoning?
14 CFR Parts 23 and 25 and CAM 4b.
When drilling stainless steel, the drill used should have an included angle of
140° and turn at a low speed.
When welding or cutting, the acetylene pressure gauge should never be set higher than
15 psi.
Composite oxygen bottles that conform to DOT-E-8162 have a service life of
15 years or 10,000 filling cycles whichever occurs first.
When installing a rigid fuel line, 1/2 inch in diameter, at what intervals should the line be supported?
16 inches.
A piece of flat stock that is to be bent to a closed angle of 15° must be bent through an angle of
165°.
(Refer to Figure 16.) Which of the antennas shown is a typical glideslope antenna?
2
The primary alloying agent of 2024-T3 is indicated by the number
2
Which part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture?
2
(Refer to Figure 15.) What is the approximate drag load on an antenna with a frontal area of .125 square feet installed on an aircraft with a speed of 225 mph?
2.069 pounds.
Although dents in the heel of a bend are not permissible, they are acceptable in the remainder of a hydraulic tube providing they are less than what percent of the tube diameter?
20 percent.
Which rivet may be used as received without further treatment?
2117-T3.
(Refer to Figure 21.) Determine what pressure is acceptable for a fire extinguisher when the surrounding area temperature is 33°F. (Rounded to the nearest whole number.)
215 to 302 psig.
(Refer to Figure 10.) The trunnion nut on an aircraft landing gear requires a torque of 320 inch-pounds. To reach the nut, a 2-inch straight adapter must be used on an 18-inch torque wrench. How many foot-pounds will be indicated on the torque wrench when the required torque of the nut is reached?
24
To be eligible for recharging, a DOT 3HT oxygen cylinder must have been hydrostatically tested every three years and be retired from service after
24 years or 4,380 filling cycles.
A barometric altimeter indicates pressure altitude when the barometric scale is set at
29.92 "Hg.
At sea level, when the average atmospheric pressure is 14.7 psi, the barometric pressure is
29.92 "Hg.
(Refer to Figure 18.) Which of the batteries are connected together incorrectly?
3
(Refer to Figure 3.) Which is the grip length of the flush rivet?
3
(Refer to Figure 8.) Identify the cable that is used in primary control systems and in other places where operation over pulleys is frequent.
3
What is the minimum amount of time to wait for tires to cool before checking tire pressure?
3 hours.
A hydraulic accumulator is charged with an air preload of 1,000 psi. When a hydraulic system pressure of 3,000 psi is developed, the pressure on the air side of the accumulator will be
3,000 psi.
(Refer to Figure 15.) What is the approximate drag load on an antenna with a frontal area of .137 square feet installed on an aircraft with a speed of 275 mph?
3.387 pounds.
(Refer to Figure 5.) What is the length of flat A?
3.7 inches.
(Refer to Figure 4.) The length of flat A is
3.750 inches.
A special bolt in a landing gear attachment requires a torque value of 440 inch-pounds. How many foot-pounds are required?
36.6
Fairleads should never deflect the alignment of a cable more than
3°.
(Refer to Figure 6.) What is dimension D? Setback = .252 Bend allowance = .345
4.182.
(Refer to Figure 14.) One hour after an oxygen system was charged for a leakage check, the oxygen pressure gauge read 460 psi at 63°F; 6 hours later the temperature was 51°F. (A 5 psi change is the maximum allowable in a 6-hour period.) What pressure gauge readings would be acceptable to remain within the allowable limits?
445 to 450 psi.
(Refer to Figure 21.) Using the chart, determine the temperature range for a fire-extinguishing agent storage container with a pressure of 330 psig. (Consider 330 psig for both minimum and maximum pressure.)
45 to 73°F.
An emergency locator transmitter (ELT) battery must be capable of furnishing power for signal transmission for at least
48 hours.
What is the voltage drop for a No. 18 copper wire 50 feet long to carry 12.5 amperes, continuous operation? Use the formula VD = RLA VD = Voltage drop R = Resistance per ft = .00644 L = Length of wire A = Amperes
4V.
(Refer to Figure 7.) What is dimension F? Setback at D = .095 Setback at E = .068 Bend allowance at D = .150 Bend allowance at E = .112
5.936.
A sheet metal repair is to be made using two pieces of 0.0625-inch aluminum riveted together. All rivet holes are drilled for 1/8-inch rivets. The length of the rivets to be used will be
5/16 inch.
The length of rivet to be chosen when making a structural repair that involves the joining of 0.032-inch and 0.064-inch aluminum sheet, drilled with a No. 30 drill, is
5/16 inch.
Which rivet is used for riveting magnesium alloy structures?
5056 aluminum.
If registration numbers are to be applied to an aircraft with a letter height of 12 inches, what is the minimum space required for the registration mark N1683C? Note: 2/3 x height = character width. 1/6 x height = width for 1. 1/4 x 2/3 height = spacing. 1/6 x height = stroke or line width.
52 inches.
How many MS20470 AD-4-6 rivets will be required to attach a 10 x 5 inch plate, using a single row of rivets, minimum edge distance, and 4D spacing?
56
(Refer to Figure 5.) What is the flat layout dimension?
6.8 inches.
Which fiber to resin (percent) ratio for advanced composite wet lay-ups is generally considered the best for strength?
60:40.
What is the maximum vapor pressure allowable for an aircraft fuel?
7 psi.
When testing the strength of Grade A cotton fabric covering an aircraft that requires only intermediate grade, the minimum acceptable strength the fabric must have is
70 percent of the original strength for intermediate fabric.
What should be the included angle of a twist drill for soft metals?
90°.
(Refer to Figure 6.) Determine the dimensions of A, B, and C in the flat layout. Setback = .252 Bend allowance = .345
A = .748, B = 1.496, C = 1.248.
(Refer to Figure 29.) What kind of antenna is this?
A VOR and localizer antenna.
(Refer to Figure 33.) What kind of antenna is this?
A VOR/glide slope antenna.
(Refer to Figure 34.) What kind of antenna is this?
A VOR/glide slope antenna.
How would an airspeed indicator be marked to show the best rate-of-climb speed (one engine inoperative)?
A blue radial line.
Which of the following is the best means to use when removing wet snow from an aircraft?
A brush or a squeegee.
(Refer to Figure 25.) What kind of antenna is this?
A canted antenna.
Who is authorized to repair an aircraft instrument?
A certificated repair station approved for that class instrument.
(Refer to Figure 24.) What kind of antenna is this?
A dipole antenna.
How does the magnetic brake used to stop rotation of an electric motor armature operate?
A friction brake is applied by a spring and released by a magnet.
When humidity is low, what is likely to occur if hydrated wash primer is applied to unpainted aluminum and then, 30 to 40 minutes later, a finish top coat is applied?
A glossy, blush-free finish.
What landing gear warning device(s) is/are incorporated on retractable landing gear aircraft?
A horn or other aural device and a red warning light.
What occurs when a visual smoke detector is activated?
A lamp within the indicator illuminates automatically.
(Refer to Figure 30.) What kind of antenna is this?
A lightning detector system antenna.
(Refer to Figure 31.) What kind of antenna is this?
A marker beacon receiver antenna.
(Refer to Figure 27.) What kind of antenna is this?
A radar beacon transponder antenna.
(Refer to Figure 32.) What kind of antenna is this?
A radar beacon transponder antenna.
What method is used to detect the thermal discharge of a built-in fire-extinguisher system?
A rupture of the red plastic disk in the thermal discharge line.
When hydraulic system pressure control and relief units fail to function properly, how are most systems protected against overpressure?
A shear section on the main hydraulic pump drive shaft.
Why does the Fenwal fire-detection system use spot detectors wired parallel between two separate circuits?
A short may exist in either circuit without causing a false fire warning
What type of valve is used in the brake actuating line to isolate the emergency brake system from the normal power brake control valve system?
A shuttle valve.
What type of bit should be used to drill holes in Plexiglas?
A specially modified twist drill.
Which of the following are characteristics of a chemical or solid-state oxygen system?
A volume storage capacity about three times that of compressed oxygen and system generators that are inert below 400°F, even under severe impact.
Where is the buttock line or buttline of an aircraft?
A width measurement left or right of, and parallel to, the vertical centerline.
What action should be taken whenever maintenance is performed that will affect the landing gear system performance?
The aircraft should be placed on jacks and a retraction test should be performed.
If the travel of an airplane's controls is correct but the cables are rigged exceptionally tight, what probable effect will this have when flying the airplane?
The airplane will be heavy on the controls.
What will be the result if the instrument static pressure line becomes disconnected inside a pressurized cabin during cruising flight?
The altimeter and airspeed indicator will both read low.
What would be the effect if the piston return spring broke in a brake master cylinder?
The brakes would drag.
In a generator, what eliminates any possible sparking to the brush guides caused by the movement of the brushes within the holder?
The brush pigtail.
What does a reciprocating engine manifold pressure gauge indicate when the engine is not operating?
The existing atmospheric pressure.
In an operating vapor-cycle cooling system, if the two lines connected to the expansion valve are essentially the same temperature, what does this indicate?
The expansion valve is not metering freon properly.
A hydraulic system operational check during ground runup of an aircraft indicates that the wing flaps cannot be lowered using the main hydraulic system, but can be lowered by using the emergency hand pump. Which is the most likely cause?
The fluid level in the reservoir is low.
If fluid is added to a reservoir in a constant pressure hydraulic system while the system is pressurized, what will result?
The fluid level will increase when system pressure is reduced.
On transport category aircraft what might be an indication of an over pressure event of the aircraft oxygen system?
The green thermal expansion disk missing
Severe kickback of the emergency hydraulic hand pump handle during the normal intake stroke will indicate which of the following?
The hand pump outlet check valve is sticking open.
Which statement concerning a welding process is true?
The inert-arc welding process uses an inert gas to protect the weld zone from the atmosphere.
What is the viscosity of hydraulic fluid?
The internal resistance of a fluid which tends to prevent it from flowing
What is one effect a restricted compensator port of a master cylinder will have on a brake system?
The restriction will cause slow release of the brakes.
What does a steady stream of bubbles indicate when servicing a vapor cycle air conditioning system?
The system is under charged.
What precautions must be observed if a gravity-feed fuel system is permitted to supply fuel to an engine from more than one tank at a time?
The tank airspaces must be interconnected.
Which statement concerning the 100-hour inspection of an airplane equipped with a push-pull tube-type control system is true?
The threaded rod ends should be checked for the amount of thread engagement by means of the inspection hole provided.
How can it be determined if a transformer winding has some of its turns shorted together?
The transformer will get hot in normal operation.
Before fueling an aircraft by using the pressure fueling method, what important precaution should be observed?
The truck pump pressure must be correct for that refueling system.
Which statement is true in regard to welding heat-treated magnesium?
The welded section does not have the strength of the original metal.
According to Part 23, what minimum required markings must be placed at or near each appropriate fuel filler cover for reciprocating engine-powered airplanes?
The word 'Avgas' and the minimum fuel grade.
What markings must be placed on or near each appropriate fuel filler cover on standard category aircraft?
The word 'Avgas' and the minimum fuel grade.
What is one advantage of piston-type hydraulic motors over electric motors?
There is no fire hazard if the motor is stalled.
Which valve installed in a hydraulic system will have the highest pressure setting?
Thermal relief valve.
What is used as a temperature-sensing element in an electrically heated windshield?
Thermistor.
What maintains normal windshield temperature control in an electrically heated windshield system?
Thermistors.
What method is usually employed to control the temperature of an anti-icing system using surface combustion heaters?
Thermo-cycling switches.
Which fire-detection system measures temperature rise compared to a reference temperature?
Thermocouple.
What is one of the determining factors which permits machine countersinking when flush riveting?
Thickness of the material is greater than the thickness of the rivet head.
(Refer to Figure 22.) What kind of antenna is this?
This is a loop and sense antenna.
(Refer to Figure 23.) What is this antenna used for?
This is an altitude encoder used with transponders.
What is the minimum spacing for a single row of aircraft rivets?
Three times the diameter of the rivet shank.
A fully integrated autopilot controls the aircraft around how many axes?
Three.
How many cycles of AC voltage are produced in a six-pole alternator of the revolving-field type for each revolution of the rotor?
Three.
How many of the following are controlled by gyroscopes? 1. Attitude indicator. 2. Heading indicator. 3. Turn needle of the turn-and-slip indicator.
Three.
Why do most aircraft tire manufacturers recommend that the tubes in newly installed tires be first inflated, fully deflated, and then reinflated to the correct pressure?
To allow the tube to position itself correctly inside the tire.
Why is it necessary to use flux in all silver soldering operations?
To chemically clean the base metal of oxide film.
When working with high pressure, high performance tires, why is it recommended to deflate the tires when removing wheels from the axle?
To ensure safety in case of a defective wheel or broken tie bolts.
What is the purpose of a gusset or gusset plate used in the construction and repair of aircraft structures?
To join and reinforce intersecting structural members.
Why is it necessary to vent all aircraft fuel tanks?
To limit pressure differential between the tank and atmosphere.
What is one purpose of a fuel tank vent?
To maintain atmospheric pressure.
What is the purpose of pressurizing the aircraft cabin?
To make human flight possible in the hostile environment of the upper atmosphere.
What is the purpose of the selection of derated switches for known continuous load current applications?
To obtain reasonable switch efficiency and service life.
What is the purpose of flapper-type check valves in integral fuel tanks?
To prevent fuel from flowing away from the boost pumps.
What is the purpose of the oil separator in the pneumatic deicing system?
To protect the deicer boots from oil deterioration.
Finishing tape (surface tape) is used for what purpose?
To provide additional wear resistance over the edges of fabric forming structures.
Why are the iron cores of most induction coils laminated?
To reduce the effects of eddy currents.
Why are integral fuel tanks used in many large aircraft?
To reduce weight.
What is the primary purpose of an autopilot?
To relieve the pilot of control of the aircraft during long periods of flight.
What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treatment?
To retard age hardening.
What is the purpose of the distributor valve in a deicing system utilizing deicer boots?
To sequence the deicer boots inflations symmetrically.
Why are centrifugal-type boost pumps used in fuel systems of aircraft operating at high altitude?
To supply fuel under pressure to engine-driven pumps.
What is the usual cause of runs and sags in aircraft finishes?
Too much material applied in one coat.
The auxiliary (tail) rotor of a helicopter permits the pilot to compensate for and/or accomplish which of the following?
Torque and directional control.
Which statement is correct concerning torque effect on helicopters?
Torque direction is the opposite of rotor blade rotation.
Which procedure is correct when using a reamer to finish a drilled hole to the correct size?
Turn the reamer only in the cutting direction.
What is the maximum amount of time a circuit can be in operation and still be an intermittent duty circuit?
Two minutes.
Which of the following is employed to maintain lateral stability when jettisoning fuel?
Two separate independent systems.
What is the minimum edge distance for aircraft rivets?
Two times the diameter of the rivet shank.
How many vents, arranged so that they are not likely to become plugged at the same time, must be used in multiengine fuel systems?
Two.
If it is necessary to adjust several pressure regulating valves in a hydraulic system, what particular sequence, if any, should be followed?
Units with the highest pressure settings are adjusted first.
Movement of the cockpit control toward the nosedown position during a ground operational check of the elevator trim tab system will cause the trailing edge of the trim tab to move in which direction?
Upward regardless of elevator position.
What nondestructive checking method is normally used to ensure that the correct amount of swaging has taken place when installing swaged-type terminals on aircraft control cable?
Use a terminal gauge to check the diameter of the swaged portion of the terminal.
What can be done to eliminate or minimize the microbial growth problem in an aircraft jet fuel tank?
Use anti-icing and antibacterial additives.
What is the appropriate method for installing pre-insulated terminal lugs and splices to electric wires?
Using a crimping tool to secure the terminal lug.
Which condition would be most likely to cause excessive vacuum in a vacuum system?
Vacuum relief valve improperly adjusted.
What is the source of pressure for inflating deicer boots on reciprocating engine aircraft?
Vane-type pump.
Which instruments are connected to an aircraft's static pressure system only?
Vertical speed indicator and altimeter.
Which instruments are connected to an aircraft's pitot-static system?
Vertical speed indicator, altimeter, and airspeed indicator.
In what position should the bottle be placed when adding liquid freon to a vapor-cycle cooling system?
Vertical with the outlet at the bottom.
What reference tool is used to determine how the fiber is to be oriented for a particular ply of fabric?
Warp clock (or compass).
Composite fabric material is considered to be the strongest in what direction?
Warp.
Which type of coating typically includes phosphoric acid as one of its components at the time of application?
Wash primer.
When necessary, what type of cutting fluid is usually acceptable for machining composite laminates?
Water only.
What method of repair is recommended for a steel tube longeron dented at a cluster?
Welded patch plate.
Which of the following safeguards ensures proper system operation and mitigates damage to non-metallic components of the hydraulic system?
When adding fluid to a system, use the type specified in the aircraft manufacturer's maintenance manual or on the instruction plate affixed to the reservoir or unit being serviced.
Which statement relating to electric wiring is true?
When attaching a terminal to the end of an electric cable, it should be determined that the strength of the cable-to-terminal joint is at least equal to the tensile strength of the cable itself.
When would a U.S. resident NOT be required to hold a Federal Communications Commission (FCC) Restricted Radio Telephone Operator Permit to operate two-way aircraft VHF radio equipment?
When flying or communicating within the United States.
Which is considered good practice concerning the installation of acrylic plastics?
When rivets are used, adequate spacer or other satisfactory means to prevent excessive tightening of the frame to the plastic should be provided.
When must the radio station license be displayed in an aircraft equipped with a two-way radio?
When the aircraft is operated outside the United States.
When will a continuous horn provide a warning in the cockpit?
When the throttle is retarded and gear is not down and locked.
When must the emergency locator transmitter (ELT) battery be replaced (other than reading the replacement date)?
When the transmitter has been in use for more than one cumulative hour.
In the diluter demand oxygen regulator, when does the demand valve operate?
When the user breathes.
At what point in the landing operation does normal skid control perform its function?
When wheel rotation deceleration indicates an impending skid.
Some aircraft are protected against airframe icing by heating the leading edges of the airfoils and intake ducts. When is this type of anti-ice system usually operated during flight?
Whenever icing conditions are first encountered or expected to occur.
What marking color is used to indicate if a cover glass has slipped?
White.
Which of these methods may be used to inspect fiberglass/honeycomb structures for entrapped water?
X-ray and backlighting.
Airworthiness Directives (ADs) are designed to notify the
aircraft owners and other interested persons of unsafe conditions and prescribes the condition under which the product may continue to be operated.
For an individual (not a repair station) to conduct a complete 100-hour inspection on an aircraft and approve it for return to service requires a mechanic certificate with
airframe and powerplant ratings.
Aircraft antenna must be grounded to the
airframe.
If the right wing of a monoplane is improperly rigged to a greater angle of incidence than designated in the manufacturer's specifications, it will cause the
airplane to be off balance both laterally and directionally.
The purpose of a localizer is to
align the airplane with the center of the runway.
After cleaning or replacing the filtering element in a combustion heater fuel system, the system should be pressurized and
all connections checked for leaks.
The purpose of the dump valve in a pressurized aircraft is to relieve
all positive pressure from the cabin.
The purpose of a joggle is to
allow clearance for a sheet or an extrusion.
Lockout deboosters are primarily pressure reducing valves that
allow full debooster piston travel without fluid from the high pressure side entering the low pressure chamber.
The function of a display controller in an EFIS is to
allow the pilot to select the appropriate system configuration for the current flight situation.
When the lift of an airfoil increases, the drag will
also increase.
The operation of an aircraft combustion heater is usually controlled by a thermostat circuit which
alternately turns the fuel on and off, a process known as cycling.
The purpose of a rectifier in an electrical system is to change
alternating current to direct current.
Instrument static system leakage can be detected by observing the rate of change in indication of the
altimeter after suction has been applied to the static system to cause a prescribed equivalent altitude to be indicated.
A radar altimeter indicates
altitude above ground level.
A fuel totalizer is a component which indicates the
amount of fuel in all tanks.
In selecting a torch tip size to use in welding, the size of the tip opening determines the
amount of heat applied to the work.
Aircraft fuse capacity is rated in
amperes.
A unit which transforms hydraulic pressure into linear motion is called
an actuating cylinder.
The electronic-type fuel quantity indicating system consists of a bridge circuit,
an amplifier, an indicator, and a tank unit.
In an antiskid system, wheel skid is detected by
an electrical sensor.
An antiskid system is
an electrohydraulic system.
The rotor in an Autosyn remote indicating system uses
an electromagnet.
An aircraft electrical circuit control relay is
an electronically operated switch.
A high-speed aircraft tire with a sound cord body and bead may be recapped
an indefinite number of times.
During ground operation, aircraft generator cooling is usually accomplished by
an integral fan.
A battery-generator system provides direct current. On installations requiring alternating current from the battery-generator system, it is necessary to have
an inverter.
If any one generator in a 24-volt DC system shows low voltage, the most likely cause is
an out-of-adjustment voltage regulator.
MS20426AD-6-5 indicates a countersunk rivet which has
an overall length of 5/16 inch.
Repairing advanced composites using materials and techniques traditionally used for fiberglass repairs is likely to result in
an unairworthy repair.
Buffeting is the intermittent application of forces to a part of an airplane. It is caused by
an unsteady flow from turbulence.
The acute angle formed by the chord line of a wing and the relative wind is known as the
angle of attack.
Proper prepreg composite lay-up curing is generally accomplished by
applying external heat and pressure.
Movement of an airplane along its lateral axis (roll) is also movement
around or about the longitudinal axis controlled by the ailerons.
Relief valves are used in pneumatic systems
as damage-preventing units.
The preferred location of an ELT is
as far aft as possible but forward of the empennage.
The purpose of a glideslope system is to
assist the pilot in making a correct angle of descent to the runway.
The purpose of spring tabs or servo tabs is to
assist the pilot in moving the control surfaces.
Aircraft tire pressure should be checked
at least once a week or more often.
Pressure fueling of aircraft is usually accomplished through
at least one single point connection.
Compression failures in wood aircraft structures are characterized by buckling of the fibers that appear as streaks on the surface
at right angles to the grain.
When installing coaxial cable, it should be secured firmly along its entire length
at two-foot intervals.
Threaded rivets (Rivnuts) are commonly used to
attach parts or components with screws to sheet metal.
One purpose of the freewheeling unit required between the engine and the helicopter transmission is to
automatically disengage the rotor from the engine in case of an engine failure.
The primary difference between aviation breathing oxygen and other types of commercially available compressed oxygen is that
aviation breathing oxygen has had all the water vapor removed.
Before applying a protective coating to any unpainted clean aluminum, you should
avoid touching the surface with bare hands.
Extrusion of an O-ring seal is prevented in a high-pressure system by the use of a
backup ring on the side of the O-ring away from the pressure.
If the (+) terminal of a voltmeter is connected to the (-) terminal of the source voltage and the (-) terminal of the meter is connected to the (+) terminal of the source voltage, the voltmeter will read
backwards.
A pressurization controller uses
barometric pressure, cabin altitude, and cabin rate of change.
Cabin upholstery materials installed in current standard category airplanes must
be at least flame resistant.
Electric wiring installed in aircraft without special enclosing means (open wiring) offers the advantages of ease of installation, simple maintenance, and reduced weight. When bundling open wiring, the bundles should
be limited as to the number of cables to minimize damage from a single electrical fault.
The oxyacetylene flame used for aluminum welding should
be neutral and soft.
If the liquid level gauge in a vapor-cycle cooling system indicates a low freon charge, the system should
be operated for a period of time to reach a stable condition and then the freon level rechecked.
A piece of sheet metal is bent to a certain radius. The curvature of the bend is referred to as the
bend radius.
If a brake debooster is used in a hydraulic brake system, its position in the system will be
between the brake control valve and the brake actuating cylinder.
Turbine engine air used for air conditioning and pressurization is generally called
bleed air.
Characteristics of MIL-H-7644 hydraulic fluid are
blue color, vegetable base, will burn, natural rubber seals.
The markings on the head of a Dzus fastener identify the
body diameter, type of head, and length of the fastener.
Fuel is moved overboard in most fuel jettison systems by
boost pumps.
To prevent vapor lock in fuel lines at high altitude, some aircraft are equipped with
booster pumps.
(1) A DC selsyn system is a widely used electrical method of indicating a remote mechanical movement or position. (2) A synchro-type indicating system is an electrical system used for transmitting information from one point to another. Regarding the above statements,
both 1 and 2 are true.
(1) A fuel heater can use engine bleed air as a source of heat. (2) A fuel heater can use engine lubricating oil as a source of heat. Regarding the above statements,
both 1 and 2 are true.
(1) A fuel pressure gauge is a differential pressure indicator. (2) A fuel pressure gauge indicates the pressure of the fuel entering the carburetor. Regarding the above statements,
both 1 and 2 are true.
(1) An antiskid system is designed to apply enough force to operate just below the skid point. (2) A warning lamp lights in the cockpit when the antiskid system is turned off or if there is a system failure. Regarding the above statements,
both 1 and 2 are true.
(1) Gas-turbine-engine fuel systems are very susceptible to the formation of ice in the fuel filters. (2) A fuel heater operates as a heat exchanger to warm the fuel. Regarding the above statements,
both 1 and 2 are true.
(1) There are three basic types of DC motors; series, shunt, and compound. (2) In the series motor, the field windings, consisting of relatively few turns of heavy wire, are connected in series with the armature winding. Regarding the above statements,
both 1 and 2 are true.
(1) When an airplane is slowed below approximately 20 mph, the antiskid system automatically deactivates to give the pilot full control of the brakes for maneuvering and parking. (2) An antiskid system consists basically of three components; wheel speed sensors, control box, and control valves. Regarding the above statements,
both 1 and 2 are true.
In reference to aircraft fire-extinguishing systems, (1) during removal or installation, the terminals of discharge cartridges should be grounded or shorted. (2) before connecting cartridge terminals to the electrical system, the system should be checked with a voltmeter to see that no voltage exists at the terminal connections. Regarding the above statements,
both 1 and 2 are true.
VHF radio signals are commonly used in
both VOR navigation and ATC communications.
A turn coordinator instrument indicates
both roll and yaw.
Placing a piece of cloth around a stainless steel control cable and running it back and forth over the length of the cable is generally a satisfactory method of inspecting for
broken strands.
Proper wing twist in a sheet metal constructed wing can usually be checked by utilizing a
bubble level and special fixtures described by the manufacturer.
When an aircraft's oxygen system has developed a leak, the lines and fittings should be
bubble tested with a special soap solution manufactured specifically for this purpose.
Shallow scratches in sheet metal may be repaired by
burnishing.
The major advantages of alternating current (AC) over direct current (DC) is the fact that its current and voltage can easily be increased or decreased
by means of a transformer.
The removal of air from an aircraft hydraulic system is generally accomplished
by operating the various hydraulic components through several cycles.
Radio equipment installations made in accordance with Supplemental Type Certificate data require approval for return to service
by the holder of an inspection authorization.
Alloy 2117 rivets are heat treated
by the manufacturer and do not require heat treatment before being driven.
One advantage of electrical and electronic fuel quantity indicating systems is that the indicator
can be located any distance from the tank(s).
The probe of a capacitance-type fuel level gauge is essentially a
capacitor with fuel and air acting as a dielectric.
In an electronic-type fuel quantity indicating system, the tank sensing unit is a
capacitor.
Nose gear centering cams are used in many retractable landing gear systems. The primary purpose of the centering device is to
center the nosewheel before it enters the wheel well.
When installing a DME antenna, it should be aligned with the
centerline on the airplane.
Rivet pitch is the distance between the
centers of adjacent rivets in the same row.
Rivet gauge, or transverse pitch is the distance between the
centers of rivets in adjacent rows.
The type of fuel-boost pump that separates air and vapor from the fuel before it enters the line to the carburetor is the
centrifugal-type pump.
The commutator of a generator
changes alternating current produced in the armature into direct current as it is taken from the armature.
When Refrigerant-12 is passed over an open flame, it
changes to phosgene gas.
When servicing an air conditioning system that has lost all of its freon, it is necessary to
check oil and add as necessary, evacuate the system, and add freon.
The vast majority of aircraft control cables are terminated with swaged terminals, that must be
checked with a go-no-go gauge before and after, to show compliance with the manufacturer's requirements after the swaging operation.
Turbine engine exhaust gas temperatures are measured by using
chromel/alumel thermocouples.
A circuit breaker is installed in an aircraft electrical system primarily to protect the
circuit and should be located as close to the source as possible.
A certain switch is described as a single-pole, double-throw (SPDT) switch. The throw of a switch indicates the number of
circuits each pole can complete through the switch.
When patching a plywood skin, abrupt changes in cross-sectional areas which will develop dangerous stress concentration should be avoided by using
circular or elliptical patches.
The presence of fuel stains around a fuel nozzle would indicate
clogged fuel nozzle.
When servicing an air/oil shock strut with MIL-5606 the strut should be
collapsed and fluid added at the filler opening.
The vertical flight of a helicopter is controlled by
collective pitch changes.
The purpose of a relief valve in a brake system is to
compensate for thermal expansion.
The purpose of a diaphragm in a vane-type fuel pump is to
compensate fuel pressures to altitude changes.
A faint line running across the grain of a wood spar generally indicates
compression failure.
Two possible sources of heat for the operation of a wing thermal anti-icing system are
compressor bleed air and aircraft electrical system.
The point at which freon flowing through a vapor-cycle cooling system gives up heat and changes from a gas to a liquid is the
condenser.
Arcing in an electrically heated windshield panel usually indicates a breakdown in the
conductive coating.
Most variable displacement aircraft hydraulic pumps in use
contain a built-in means of system pressure regulation.
Cylinders used to transport and store acetylene
contain acetone.
High pressure cylinders used to transport and store acetylene must
contain acetone.
Oxygen systems in unpressurized aircraft are generally of the
continuous-flow and pressure-demand types.
Microswitches are used primarily as limit switches to
control electrical units automatically.
The purpose of restrictors in hydraulic systems is to
control the rate of movement of hydraulically operated mechanisms.
The purpose of a subcooler in a vapor-cycle cooling system is to
cool the freon to prevent premature vaporization.
A very thin and pointed tip on a soldering copper is undesirable because it will
cool too rapidly.
Fungicide and mildewicide additives are important for fabric covered aircraft, such as
cotton and linen.
To protect seals from damage when installed over a threaded section, the threaded section should be
covered with a suitable sleeve.
If no scratches are visible after transparent plastic enclosure materials have been cleaned, their surfaces should be
covered with a thin coat of wax.
If an aircraft's transparent plastic enclosures exhibit fine cracks which may extend in a network over or under the surface or through the plastic, the plastic is said to be
crazing.
The most common method of attaching a pin or socket to an individual wire in an MS electrical connector is by
crimping.
In the American Wire Gauge (AWG) system of numbers used to designate electrical wire sizes, the number assigned to a size is related to its
cross-sectional area.
If masking tape is applied to an aircraft, such as for trim spraying, and is left on for several days and/or exposed to heat, it is likely that the tape will
cure to the finish and be very difficult to remove.
The most common method of regulating the voltage output of a compound DC generator is to vary the
current flowing through the shunt field coils.
The nominal rating of electrical switches refers to continuous
current rating with the contacts closed.
The primary considerations when selecting electric cable size are
current-carrying capacity and allowable voltage drop.
When considering an alteration, the criteria upon which the selection of electric cable size should be based are
current-carrying capacity and allowable voltage drop.
Movement about the lateral axis (pitch) in a helicopter is effected by movement of the
cyclic pitch control
Movement about the longitudinal axis (roll) in a helicopter is effected by movement of the
cyclic pitch control.
Magnetic compass bowls are filled with a liquid to
dampen the oscillation of the float.
Acetylene at a line pressure above 15 psi is
dangerously unstable.
The inductor-type inverter output voltage is controlled by the
dc stator field current.
The cable-operated control system of an all-metal aircraft, not incorporating a temperature compensating device, has been rigged to the correct tension in a heated hangar. If the aircraft is operated in very cold weather, the cable tension will
decrease when the aircraft structure and cables become cold.
Chines are used on some aircraft nose wheel tires to help
deflect water away from the fuselage.
The universal propeller protractor can be used to measure
degrees of flap travel.
A hydraulic pump is a constant-displacement type if it
delivers a uniform rate of fluid flow.
The most common cause of false fire warnings in continuous-loop fire-detection systems is
dents, kinks, or crushed sensor sections.
If a generator is equipped with a vibrator-type voltage regulator, the actual time the voltage regulator points remain open
depends on the load carried by the generator.
The method of mounting aircraft instruments in their respective panels depends on the
design of the instrument case.
Smoke detection instruments are classified by their method of
detection.
A squib, as used in a fire-protection system, is a
device for causing the fire-extinguishing agent to be released.
A factor which determines the minimum space between rivets is the
diameter of the rivets being used.
The cabin pressurization modes of operation are
differential, unpressurized, and isobaric.
Data transmitted between components in an EFIS are converted into
digital signals.
Most rivets used in aircraft construction have
dimples.
The purpose of the vertical fin is to provide
directional stability.
Hydraulic fluid filtering elements constructed of porous paper are normally
discarded at regular intervals and replaced with new filtering elements.
When a diode is checked for an open circuit or a short circuit, it should be
disconnected from the circuit.
The function of a CRT in an EFIS is to
display alphanumeric data and representations of aircraft instruments.
The angle of incidence of an airplane at rest
does not change when in flight.
An aircraft may be flown beyond the 100-hour inspection requirement to reach a place where the inspection can be accomplished, provided it
does not exceed 10 flight hours.
If the control stick of an aircraft with properly rigged flight controls is moved forward and to the right, the left aileron will move
down and the elevator will move down.
If the control stick of an aircraft with properly rigged flight controls is moved rearward and to the left, the right aileron will move
down and the elevator will move up.
Fuel system components must be bonded and grounded in order to
drain off static charges.
The proper fire-extinguishing agent to use on an aircraft brake fire is
dry powder chemical.
Fuel jettisoning past the limits prescribed by Federal Aviation Regulations is usually prevented by
dump limit valves or a low-level circuit.
If several long lengths of electrical cable are to be installed in rigid conduit, the possibility of damage to the cable as it is pulled through the conduit will be reduced by
dusting the cable with powdered soapstone.
During inspection of the flight control system of an airplane equipped with differential-type aileron control, side-to-side movement of the control stick will cause
each aileron to have a greater up travel (from the streamlined position) than down travel.
A synchro transmitter is connected to a synchro receiver
electrically with wires.
Fuel flow transmitters are designed to transmit data
electrically.
The addition of avionics and associated antenna systems forward of the CG limit will affect
empty weight and useful load.
If a bladder-type fuel tank is to be left empty for an extended period of time, the inside of the tank should be coated with a film of
engine oil.
The installation of a new metal hydraulic line should be made with
enough bends to allow the tube to expand and contract with temperature changes and to absorb vibration.
The purpose of a sequence valve in a hydraulic retractable landing gear system is to
ensure operation of the landing gear and gear doors in the proper order.
Materials which are Skydrol compatible or resistant include
epoxy paints and most common aircraft metals.
If two actuating cylinders which have the same cross-sectional area but different lengths of stroke are connected to the same source of hydraulic pressure, they will exert
equal amounts of force and will move at the same rate of speed.
The point at which freon flowing through a vapor-cycle cooling system absorbs heat and changes from a liquid to a gas is the
evaporator.
The air that is expended and no longer needed when an actuating unit is operated in a pneumatic system is
exhausted or dumped, usually overboard.
On all aircraft equipped with retractable landing gear, some means must be provided to
extend the landing gear if the normal operating mechanism fails.
(Refer to Figure 19.) What is the indication of the red landing gear position light under the following conditions? Aircraft on jacks. Landing gear in transit. Warning horn sounding.
extinguished.
The air-cycle cooling system produces cold air by
extracting heat energy across an expansion turbine.
The pole pieces or shoes used in a DC generator are a part of the
field assembly.
Residual voltage is a result of magnetism in the
field shoes.
Fiberglass laminate damage not exceeding the first layer or ply can be repaired by
filling with a putty consisting of a compatible resin and clean, short glass fibers.
When bleeding aircraft brakes, one of the indications that the air has been purged from the system is
firm brake pedals.
Fungicidal dopes are used in aircraft finishing as the
first coat to prevent fabric rotting and are applied thin enough to saturate the fabric.
Many fuel tanks incorporate _________________ valves to prevent fuel from flowing away from the boost pump or tank outlet when the aircraft is in a high 'G' maneuver.
flapper
One of the distinguishing characteristics of an open-center selector valve used in a hydraulic system is that
fluid flows through the valve in the OFF position.
The primary purpose of a hydraulic actuating unit is to transform
fluid pressure into useful work.
Oxides form very rapidly when alloys or metals are hot. It is important, therefore, when welding aluminum to use a
flux.
The left brake is dragging excessively on an airplane on which no recent brake service work has been performed. The most probable cause is
foreign particles stuck in the master cylinder compensating port.
If it is necessary to compute a bend allowance problem and bend allowance tables are not available, the neutral axis of the bend can be
found by adding approximately one-half of the stock thickness to the bend radius.
The position of the thermostatic expansion valve in a vapor-cycle cooling system is determined by temperature and pressure of the
freon in the outlet of the evaporator.
The dihedral angle of a wing may be measured by placing a straightedge and level protractor on the
front spar.
Aircraft pressure fueling systems instructional procedures are normally placarded on the
fuel control panel access door.
On a large aircraft pressure refueling system, a pressure refueling receptacle and control panel will permit one person to
fuel or defuel any of the tanks on an aircraft.
Electric circuits are protected from overheating by
fuses.
Moisture, mildew, chemicals, and acids have no effect on
glass fabric.
The strength of a well-designed and properly prepared wood splice joint is provided by the
glue
The voltage in an AC transformer secondary that contains twice as many loops as the primary will be
greater and the amperage less than in the primary.
One advantage of using AC electrical power in aircraft is
greater ease in stepping the voltage up or down.
The coefficient of expansion of most plastic enclosure materials is
greater than both steel and aluminum.
High-pressure cylinders containing oxygen for aviation use can be identified by their
green color and the words AVIATOR'S BREATHING OXYGEN stenciled in 1-inch white letters.
Circuits that must be operated only in an emergency or whose inadvertent activation could endanger a system frequently employ
guarded switches.
Built-in aircraft fire-extinguishing systems are ordinarily charged with
halogenated hydrocarbons and nitrogen
After installation of a rebuilt hydraulic hand pump, it is found that the handle cannot be moved in the pumping direction (pressure stroke). The most likely cause is an incorrectly installed
hand pump outport check valve.
A rivet set used to drive MS20470 rivets should
have a slightly greater radius than the rivet head.
A hydraulic system referred to as a 'power pack' system will
have all hydraulic power components located in one unit.
When routing a fuel line between two rigidly mounted fittings the line should
have at least one bend between such fittings.
One of the best ways to assure that a properly prepared batch of matrix resin has been achieved is to
have mixed enough for a test sample.
Clad aluminum alloys are used in aircraft because they
have surface layers of pure aluminum or aluminum alloy bonded to the core material to inhibit corrosion.
A circuit protection device called a current limiter is essentially a slow-blow fuse and is designed to be used in
heavy power circuits.
The shielding gases generally used in the Gas Tungsten Arc (GTA) welding of aluminum consist of
helium or argon, or a mixture of helium and argon.
Power boost brake systems are used on aircraft that have
high landing speeds.
Heat exchanger cooling units are required in some aircraft hydraulic systems because of
high pressures and high rates of fluid flow.
The starting current of a series-wound DC motor, in passing through both the field and armature windings, produces a
high starting torque.
Hydraulic system thermal relief valves are set to open at a
higher pressure than the system relief valve.
A carbon dioxide (CO(2)) hand-held fire extinguisher may be used on an electrical fire if the
horn is nonmetallic.
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud length is measured in
hundredths of an inch.
A worn hydraulic pump shaft seal can normally be detected by
hydraulic fluid flowing from the pump drain line.
Some hydraulic systems incorporate a device which is designed to remain open to allow a normal fluid flow in the line, but closed if the fluid flow increases above an established rate. This device is generally referred to as a
hydraulic fuse.
Before a high-pressure oxygen cylinder is serviced, it must be the correct type and have been
hydrostatically tested within the proper time interval.
Fuel heaters are used with fuel systems for turbine engines to prevent ____________ in the fuel from clogging system filters.
ice crystals
An aircraft that is due an annual inspection may be flown
if a special permit has been issued for the aircraft.
Laminated wood spars may be substituted for solid rectangular wood spars
if the same quality wood is used in both.
Large airplanes and turbine-powered multiengine airplanes operated under 14 CFR Part 91, General Operating and Flight Rules, must be inspected
in accordance with an inspection program authorized under Part 91, Subpart E.
Instructions concerning the type of fluid and amount of air pressure to be put in a shock strut are found
in the aircraft manufacturer's service manual.
A small amount of water in a vapor cycle cooling system can freeze
in the expansion valve and stop the entire system operation.
An electrical type fuel quantity indicating system consists of an indicator in the cockpit and a float
in the tank that moves a connecting arm to the wiper on a variable resistor in the tank.
Frost or ice buildup on a vapor-cycle cooling system evaporator would most likely be caused by
inadequate airflow through the evaporator.
If a pilot reports that an airplane flies left wing heavy, this condition may be corrected by
increasing the angle of incidence of the left wing, or decreasing the angle of incidence of the right wing, or both.
When DC generators are operated in parallel to supply power for a single load, their controls include an equalizer circuit to assure that all generators share the load equally. The equalizer circuit operates by
increasing the output of the low generator and decreasing the output of the high generator until they are equal.
Aluminum wire must be stripped very carefully because
individual strands will break easily after being nicked.
An emergency supply of fluid is often retained in the main hydraulic system reservoir by the use of a standpipe. The supply line is connected to the
inlet of the main hydraulic system.
An automatic damping action occurs at the steering damper if for any reason the flow of high-pressure fluid is removed from the
inlet of the steering damper.
When using the voltage drop method of checking circuit resistance, the
input voltage must be maintained at a constant value.
The repair for an out-of-tolerance toe-in condition of main landing gear wheels determined not to be the result of bent or twisted components consists of
inserting, removing, or changing the location of washers or spacers at the center pivotal point of the scissor torque links.
Unless otherwise specified, the radius of a bend is the
inside radius of the metal being formed.
A certificated mechanic with at least an airframe rating may perform
inspections and function checks on aircraft instruments.
A flexible hydraulic hose identified as MIL-H-8788 will have a stripe running the length of the hose. This stripe is
installed without excessive twisting.
A common cause of slow actuation of hydraulic components is
internal leakage in the actuating unit.
The method most often used in overcoming the effect of armature reaction is through the use of
interpoles.
Oxygen used in aircraft systems
is at least 99.5 percent pure and is practically water free.
When handling a high voltage capacitor in an electrical circuit, be sure it
is fully discharged before removing it from the circuit.
Stall warning systems are generally designed to begin warning the pilot when a stall
is imminent.
The angle-of-attack detector operates from differential pressure when the airstream
is not parallel to the true angle of attack of the aircraft.
If a static pressure system check reveals excessive leakage, the leak(s) may be located by
isolating portions of the line and testing each portion systematically starting at the instrument connections.
A thermocouple in a fire-detection system causes the warning system to operate because
it generates a small current when heated.
A pilot reports that the brake pedals have excessive travel. A probable cause is
lack of fluid in the brake system.
The preferred way to make permanent repairs on composites is by
laminating on new repair plies.
In the landing configuration GPWS typically monitors the radio (radar) altimeter, air data computer, instrument landing system, and
landing gear and flap positions.
A crossflow valve which is designed to bypass fluid from one side of an actuating cylinder to the other side, under certain conditions, may be found in some aircraft installed in the
landing gear system.
Engine mount members should preferably be repaired by using a
larger diameter tube with fishmouth and rosette welds.
Improper rigging of the elevator trim tab system will affect the balance of the airplane about its
lateral axis.
The elevators of a conventional airplane are used to provide rotation about the
lateral axis.
Stability about the axis which runs parallel to the line of flight is referred to as
lateral stability.
The chord of a wing is measured from
leading edge to trailing edge.
A pilot reports that when the hydraulic pump is running, the pressure is normal. However, when the pump is stopped, no hydraulic pressure is available. This is an indication of a
leaking accumulator air valve.
If a single-rotor helicopter is in forward horizontal flight, the angle of attack of the advancing blade is
less than the retreating blade.
Characteristics of MIL-H-8446 hydraulic fluid are
light purple color, phosphate ester base, fire resistant, butyl rubber seals
A fuel system must be designed to prevent fuel-vapor ignition caused by
lightning.
A sleeve, spacer, or bumper ring is incorporated in a landing gear oleo shock strut to
limit the extension stroke.
On a semi-monocoque fuselage, the skin is reinforced by longitudinal structural members called
longerons and stringers.
Wing dihedral, a rigging consideration on most airplanes of conventional design, contributes most to stability of the airplane about its
longitudinal axis.
After an automatic direction finding antenna has been installed, the
loop must be calibrated.
If an aircraft's constant-pressure hydraulic system cycles more frequently than usual and no fluid leakage can be detected, the most probable cause is
low accumulator air preload.
Static dischargers help eliminate radio interference by dissipating static electricity into the atmosphere at
low current levels.
If an aircraft shock strut (air/oil type) bottoms upon initial landing contact, but functions correctly during taxi, the most probable cause is
low fluid.
Under certain conditions, type A rivets are not used because of their
low strength characteristics.
Aircraft instrument panels are generally shock-mounted to absorb
low-frequency, high-amplitude shocks.
Instrument panel shock mounts absorb
low-frequency, high-amplitude shocks.
The primary purpose of an aircraft's fuel jettison system is to quickly achieve a
lower landing weight.
When comparing the machining techniques for stainless steel sheet material to those for aluminum alloy sheet, it is normally considered good practice to drill the stainless steel at a
lower speed with more pressure applied to the drill.
The vapor pressure of aviation gasoline is
lower than the vapor pressure of automotive gasoline.
The function of the evaporator in a freon cooling system is to
lower the temperature of the cabin air.
The evacuation of a vapor-cycle cooling system removes any water that may be present by
lowering the boiling point of the water and drawing out the vapor.
On some cabin pressurization systems, pressurization on the ground is restricted by the
main landing gear operated switch.
The purpose of the pressure regulator in a hydraulic system is to
maintain system operating pressure within a predetermined range and to unload the pump.
The primary function of the cabin pressurization system outflow valve is to
maintain the desired cabin pressure.
When overhauling electrical equipment, all necessary information should be obtained from
maintenance instructions published by the aircraft and/or equipment manufacturer.
In a typical high-pressure pneumatic system, if the moisture separator does not vent accumulated water when the compressor shuts down, a likely cause is a
malfunctioning solenoid dump valve.
The most important consideration(s) when selecting welding rod is
material compatibility.
Fiberglass damage that extends completely through a laminated sandwich structure
may be repaired.
If a rigid tube is too short for the flare to reach its seat before tightening, pulling it into place by tightening
may distort the flare.
The fusible plugs installed in some aircraft wheels will
melt at a specified elevated temperature.
The use of turbine fuels in aircraft has resulted in some problems not normally associated with aviation gasolines. One of these problems is
microbial contaminants.
Two types of hydraulic fluids currently being used in civil aircraft are
mineral base, and phosphate ester base.
If a hydraulic brake system uses neoprene rubber packing materials, the correct hydraulic fluid to service the system is
mineral-base oil.
The red radial lines on the face of an engine oil pressure gauge indicates
minimum and/ or maximum safe operating limits.
The sharpest bend that can be placed in a piece of metal without critically weakening the part is called the
minimum radius of bend.
When installing a castle nut, start alignment with the cotter pin hole at the
minimum recommended torque plus friction drag torque.
If oxygen bottle pressure is allowed to drop below a specified minimum, it may cause
moisture to collect in the bottle.
Some turbine powered aircraft have a fuel temperature indicator located in the cockpit to
monitor the fuel temperature during high altitude flight.
A series-wound DC electric motor will normally require
more current at low RPM than at high RPM.
Some electric motors have two sets of field windings wound in opposite directions so that the
motor can be operated in either direction.
As the angle of attack of an airfoil increases, the center of pressure will
move toward the leading edge.
Metal fasteners used with carbon/graphite composite structures
must be constructed of material such as titanium or corrosion resistant steel.
Heat-treated rivets in the D and DD series that are not driven within the prescribed time after heat treatment or removal from refrigeration
must be reheat treated before use.
The pneumatic (reed) type stall warning system installed in some light aircraft is activated by
negative air pressure.
When performing the static system leakage check required by 14 CFR 91.411, the technician utilizes
negative pressure.
When bending metal, the material on the outside of the curve stretches while the material on the inside of the curve compresses. That part of the material which is not affected by either stress is the
neutral line.
The oxyacetylene flame for silver soldering should be
neutral.
If the hydraulic system pressure is normal while the engine-driven pump is running, but there is no pressure after the engine has been shut off, it indicates
no air pressure in the accumulator.
The cantilever wing uses
no external bracing.
Hydraulic fluid reservoirs are sometimes designed with a standpipe in one of the outlet ports in order to assure emergency supply of fluid. The outlet port with the standpipe in it furnishes fluid to the
normal system power pump.
Rigging and alignment checks should not be undertaken in the open. However, if this cannot be avoided, the aircraft should be positioned with the
nose into the wind.
Aircraft temperature thermocouple leads may
not be altered and are designed for a specific installation.
A DME antenna should be installed on the aircraft in a position that will
not be blanked out by the wing when the aircraft is banked.
Teflon hose that has developed a permanent set from being exposed to high pressure or temperature should
not be straightened or bent further.
The operation of an angle of attack indicating system is based on detection of differential pressure at a point where the airstream flows in a direction
not parallel to the true angle of attack of the aircraft.
A certificated mechanic with airframe and powerplant ratings may
not perform repairs to aircraft instruments.
Welding over brazed or soldered joints is
not permitted.
A main difference between Lockbolt/Huckbolt tension and shear fasteners (other than their application) is in the
number of locking collar grooves.
The location of leaks and defects within the internal portions of the fuel system can usually be determined by
observing the pressure gauge and operating the selector valves.
When an aircraft is fueled from a truck or fuel farm that has not been contaminated, daily draining
of strainers and sumps is combined with periodic filter changes and inspection to ensure fuel is contaminant free.
CSD generators are usually cooled by
oil spray.
The shop head of a rivet should be
one and one-half times the diameter of the rivet shank.
The length of a rivet to be used to join a sheet of .032-inch and .064-inch aluminum alloy should be equal to
one and one-half times the rivet diameter plus .096 inch.
An aircraft pressurization cycle is normally considered to be
one complete series of events or operations that recur regularly.
Superficial scars, scratches, surface abrasion, or rain erosion on fiberglass laminates can generally be repaired by applying
one or more coats of suitable resin (room-temperature catalyzed) to the surface.
The sight line on a sheet metal flat layout to be bent in a cornice or box brake is measured and marked
one radius from the bend tangent line that is placed under the brake.
When approved, splices may be used to repair manufactured harnesses or installed wiring. The maximum number of splices permitted between any two connectors is
one.
When an MS20470D rivet is installed, its full shear strength is obtained
only after a period of age hardening.
When operationally checking an autopilot system on the ground, after the aircraft's main power has been switched on, the autopilot should be engaged
only after the gyros come up to speed and the amplifier warms up.
A CSD unit that is disconnected in flight, due to a malfunction such as overtemperature, may be reconnected
only on the ground by maintenance personnel.
The overvoltage control automatically protects the generator system when excessive voltage is present by
opening the shunt field circuit.
When inspecting a fuel system, you should check all valves located downstream of boost pumps with the pumps
operating.
If the reverse current cutout relay contact points fail to open after the generator output has dropped below battery potential, current will flow through the generator armature
opposite the normal direction and through the shunt field in the normal direction.
The cabin pressure control setting has a direct influence upon the
outflow valve opening.
If the cabin rate of climb is too great, the control should be adjusted to cause the
outflow valve to close faster.
The component that determines the pressure level in the cabin is the cabin air pressure
outflow valve.
Excessive wear in the center of the tread of an aircraft tire is an indication of
overinflation.
A contaminated oxygen system is normally purged with
oxygen.
A flexible sealing element subject to motion is a
packing.
Laminated wood is sometimes used in the construction of highly stressed aircraft components. This wood can be identified by its
parallel grain construction.
If one switch is used to control all navigation lights, the lights are most likely connected
parallel to each other and in series with the switch.
An emergency locator transmitter (ELT) is normally activated by an inertial switch or equivalent mechanism if subjected to a force of a prescribed intensity and duration. It must activate when the force is applied
parallel to the longitudinal axis of the aircraft.
When used in fire-detection systems having a single indicator light, thermal switches are wired in
parallel with each other and in series with the light.
The thermal switches of a bimetallic thermal-switch type fire-detection (single-loop) system are heat-sensitive units that complete circuits at a certain temperature. They are connected in
parallel with each other, but in series with the indicator lights.
To help minimize radio interference a capacitor will largely eliminate and provide a steady direct current if the capacitor is connected to the generator in
parallel.
Repairs or splices involving stringers on the lower surface of stressed skin metal wings are usually
permitted but are normally more critical in reference to strength in tension than similar repairs to the upper surface.
Smoke detectors that use a measurement of light transmissibility in the air are called
photoelectrical devices.
Aircraft flight control trim systems must be designed and installed so that the
pilot can determine the relative position of the trim tab from the cockpit.
An airplane which has good longitudinal stability should have a minimum tendency to
pitch.
An airspeed indicator measures the differential between
pitot and static air pressure.
To test generator or motor armature windings for opens,
place armature in a growler and connect a 110V test light on adjacent segments; light should light.
The primary purpose of a fuel tank sump is to provide a
place for contaminants and water to settle, with a drain valve to remove the impurities.
An airplane that has a tendency to gradually increase a pitching moment that has been set into motion has
poor longitudinal stability.
A fuel pressure relief valve is required on an aircraft
positive-displacement fuel pump.
Hole filling fasteners (for example, MS20470 rivets) should not be used in composite structures primarily because of the
possibility of causing delamination
The length of time that a catalyzed resin will remain in a workable state is called the
pot life.
A capacitance-type fuel quantity indicating system measures fuel in
pounds
Pressure is a term used to indicate the force per unit area. Pressure is usually expressed in
pounds per square inch.
When an aircraft altimeter is set at 29.92 "Hg on the ground, the altimeter will read
pressure altitude.
A Bourdon tube instrument may be used to indicate
pressure and temperature.
When inspecting a removable rigid fuel tank for leaks, what procedure should be followed?
pressurize the tank with air and brush with soapy water.
Grounding is electrically connecting a conductive object to the primary structure. One purpose of grounding is to
prevent development of radio frequency potentials.
The primary purpose for balancing aircraft wheel assemblies is to
prevent heavy spots and reduce vibration.
In shock struts, chevron seals are used to
prevent oil from escaping.
The primary function of the flap overload valve is to
prevent the flaps from being lowered at airspeeds which would impose excessive structural loads.
In Gas Tungsten Arc (GTA) welding, a stream of inert gas is used to
prevent the formation of oxides in the puddle.
The removal, installation, and repair of landing gear tires by the holder of a private pilot certificate on an aircraft owned or operated is considered to be
preventive maintenance.
Extension of an oleo shock strut is measured to determine the
proper operating position of the strut.
When servicing an empty shock strut with fluid, the strut should be completely compressed and extended several times to ensure
proper packing ring seating and removal of air bubbles.
The function of a fuel heater is to
protect the engine fuel system from ice formation.
Radio equipment is bonded to the aircraft in order to
provide a low-impedance ground and minimize radio interference from static electrical charges.
An aircraft instrument panel is electrically bonded to the aircraft structure to
provide current return paths.
One purpose of a jet pump in a pressurization and air conditioning system is to
provide for augmentation of airflow in some areas of the aircraft.
Normal fuel crossfeed system operation in multiengine aircraft
provides a means to maintain a balanced fuel load condition.
Excessive wear on both of the sides of a control cable pulley groove is evidence of
pulley misalignment.
Quick-disconnect couplings in hydraulic systems provide a means of
quickly connecting and disconnecting hydraulic lines without loss of fluid or entrance of air into the system.
The most important factors needed to make a flat pattern layout are
radius, thickness, and degree of bend.
An ammeter in a battery charging system is for the purpose of indicating the
rate of current used to charge the battery.
The thermocouple fire-warning system is activated by a
rate-of-temperature rise.
In general, the purpose of an aircraft transponder is to
receive an interrogation signal from a ground station and automatically send a reply back.
The function of a symbol generator (SG) in an EFIS is to
receive and process input signals from aircraft and engine sensors and send the data to the appropriate display.
Certain transport aircraft use AC electrical power for all normal operation and battery furnished DC electrical power for standby emergency use. In aircraft of this type that operate no DC generators, the batteries are kept charged by
rectifiers which use the aircraft's AC generators as a source of power.
Characteristics of MIL-H-5606 hydraulic fluid are
red color, petroleum base, will burn, uses synthetic rubber seals.
To check the air charge in a hydraulic accumulator,
reduce all hydraulic pressure, then observe the reading on the accumulator air gauge.
The poles of a generator are laminated to
reduce eddy current losses.
The purpose of wing slats is to
reduce stalling speed.
Debooster valves are used in brake systems primarily to
reduce the pressure and release the brakes rapidly.
The function of an expansion valve in a freon cooling system is to act as a metering device and to
reduce the pressure of the liquid freon.
Debooster cylinders are used in brake systems primarily to
reduce the pressure to the brake and increase the volume of fluid flow.
The I-beam wooden spar is routed to
reduce weight.
Aluminum pigment in dope is used primarily to
reflect ultraviolet from the fabric.
The purpose of the airflow metering aneroid assembly found in oxygen diluter demand regulators is to
regulate airflow in relation to cabin altitude when in diluter demand position.
Doublers are used when antennas are installed to
reinstate the structural strength of the aircraft skin.
When a fiber or nylon insert-type self-locking nut can be threaded on a bolt or stud through the insert with only the fingers, it should be
rejected.
The purpose in checking main rotor blade tracking is to determine the
relative position of the blades during rotation.
On most aircraft, the oil level of an air and oil shock strut is checked by
releasing the air and seeing that the oil is to the level of the filler plug.
Pneumatic systems utilize
relief valves.
Generally, the first step in removing an accumulator from an aircraft is to
relieve system pressure.
Before removing the filler cap of a pressurized hydraulic reservoir, in order to service the system, you must
relieve the air pressure.
The purpose of a hydraulic pressure regulator is to
relieve the pump of its load when no actuating units are being operated.
Unloading valves are used with many engine-driven hydraulic pumps to
relieve the pump pressure.
In a brake antiskid system, when an approaching skid is sensed, an electrical signal is sent to the skid control valve which
relieves the hydraulic pressure on the brake.
Prior to installation of a pneumatic surface-bonded type deicer boots, on the leading edge of the wing, you should
remove all paint from the area to be covered by the deicer boot
If the Integrated Drive Generator (IDG) scavenge oil filter is contaminated with metal, you should
remove and replace the IDG.
A correct use for acetone is to
remove grease from fabric.
Annealing of aluminum
removes stresses caused by forming.
A contaminated carbon monoxide portable test unit may be returned to service by
removing the indicating element and installing a new indicating element.
Aircraft structural units, such as spars, engine supports, etc., which have been built up from sheet metal, are normally
repairable, using approved methods.
On a periodic check of fire extinguisher containers, the pressure was not between minimum and maximum limits. What procedure should be followed?
replace the extinguisher container
Maintenance of fire-detection systems includes the
replacement of damaged sensing elements.
The lubber line on a directional gyro is used to
represent the nose of the aircraft.
Fiberglass laminate damage that extends completely through one facing and into the core
requires the replacement of the damaged core and facing
If the positive field lead between a generator and a generator control panel breaks and is shorted while the engine is running, a voltmeter connected to generator output would indicate
residual voltage.
The purpose of the baffle plate in a fuel tank is to
resist fuel surging within the fuel tank.
A voltage regulator controls generator voltage by changing the
resistance of the generator field circuit.
Bonding connections should be tested for
resistance value.
Fabric rejuvenator is used to
restore the condition of dope coatings.
The purpose of an orifice check valve is to
restrict flow in one direction and allow free flow in the other.
If an engine-driven hydraulic pump of the correct capacity fails to maintain normal system pressure during the operation of a cowl flap actuating unit, the probable cause is
restriction in the pump outlet.
A tension regulator in the flight control cable system of a large all-metal aircraft is used primarily to
retain a set tension
The metering pins in oleo shock struts serve to
retard the flow of oil as the struts are compressed.
The part of a replacement honeycomb core that must line up with the adjacent original is the
ribbon direction.
A hydraulic motor converts fluid pressure to
rotary motion.
The basic difference between an autosyn and a magnesyn indicating system is the
rotor.
An airplane is controlled directionally about its vertical axis by the
rudder.
Sandwich panels made of honeycomb construction are used on aircraft because this type of construction
saves weight while not compromising strength.
Parts fabricated from Alclad 2024-T3 aluminum sheet stock must have all
scratches, kinks, tool marks, nicks, etc., must be held to a minimum.
The component in the hydraulic system that is used to direct the flow of fluid is the
selector valve.
Part of the ADF system used on aircraft includes
sense and loop antennas.
An antiskid system is designed to
sense the deceleration rate of every main landing gear wheel and release then reapply pressure at a slightly lower value when a skid is detected.
Light refraction smoke detectors are activated when the detector
senses light reflected from smoke particles passing through a chamber.
When inspecting a composite panel using the ring test/tapping method, a dull thud may indicate
separation of the laminates.
The unit in a hydraulic system that requires a certain action to be completed before another action can begin is called a
sequence valve.
In most modern hydraulically actuated landing gear systems, the order of gear and fairing door operation is controlled by
sequence valves.
When adding a rheostat to a light circuit to control the light intensity, it should be connected in
series with the light.
One advantage of electrical and electronic fuel quantity indicating systems is that
several fuel tank levels can be read on one indicator.
The best method of repair for a fabric-covered surface which has an L-shaped tear, each leg of which is approximately 14 inches long, is to
sew with a baseball stitch from the center of the tear out toward the extremity of each leg and then dope on a patch.
Joggles in removed rivet shanks would indicate partial
shear failure.
A well-designed rivet joint will subject the rivets to
shear loads.
In a gear-type hydraulic pump, a mechanical safety device incorporated to protect the pump from overload is the
shear pin.
Installed radio equipment is protected from damage due to jolts and vibration by
shock mounts.
The best safeguards against heat buildup in aircraft tires are
short ground rolls, slow taxi speeds, minimum braking, and proper tire inflation.
In aircraft electrical systems, automatic reset circuit breakers
should not be used as circuit protective devices.
When using an ohmmeter to check the continuity of a generator field coil, the coil should
show very low resistance if it is a series field coil.
The hydraulic component that automatically directs fluid from either the normal source or an emergency source to an actuating cylinder is called a
shuttle valve.
The navigation lights of some aircraft consist of a single circuit controlled by a single switch which has an ON position and an OFF position, with no additional positions possible. This switch is referred to as a
single-pole, single-throw (SPST), two-position switch.
The Dzus turnlock fastener consists of a stud, grommet, and receptacle. The stud diameter is measured in
sixteenths of an inch.
In gas welding, the amount of heat applied to the material being welded is controlled by the
size of the tip opening.
The monocoque fuselage relies largely on the strength of
skin or covering.
When moving the mixture control on a normally operating engine into the idle cutoff position, engine RPM should
slightly increase before the engine starts to die.
A stripe or mark applied to a wheel rim and extending onto the sidewall of a tube-type tire is a
slippage mark.
When an antenna is installed, it should be fastened
so that loads imposed are transmitted to the aircraft structure.
An airplane's center of lift is usually located aft of its center of gravity
so that the airplane will have a nose-heavy tendency.
A DD rivet is heat treated before use to
soften to facilitate riveting.
The identifying marks on the heads of aluminum alloy rivets indicate the
specific alloy used in the manufacture of the rivets.
The determining factor(s) for the selection of the correct weight of textile fabric to be used in covering any type of aircraft is the
speed of the aircraft and the maximum wing loading.
An electric motor used to raise and lower a landing gear would most likely be a
split field series-wound motor.
In the air with the antiskid armed, current cannot flow to the antiskid control box because the landing gear
squat switch is open.
Aircraft electrical junction boxes located in a fire zone are usually constructed of
stainless steel.
The primary purpose of stall strips is to
stall the inboard portion of the wings first.
If a streamline cover plate is to be hand formed using a form block, a piece of dead soft aluminum should first be placed over the hollow portion of the mold and securely fastened in place. The bumping operation should be
started by tapping the aluminum lightly around the edges and gradually working down into the center.
Mild steel rivets are used for riveting
steel parts.
Oxygen and acetylene cylinders are made of
steel.
When straightening members made of 2024-T4, you should
straighten cold and reinforce.
The only practical method of maintaining a constant voltage output from an aircraft generator under varying conditions of speed and load is to vary the
strength of the magnetic field.
One method of inspecting a laminated fiberglass structure that has been subjected to damage is to
strip the damaged area of all paint and shine a strong light through the structure.
If a shock strut bottoms after it has been properly serviced, the
strut should be removed, disassembled, and inspected.
On a sheet metal fitting layout with a single bend, allow for stretching by
subtracting the setback from both legs.
Many hydraulic reservoirs contain a small quantity of fluid which is not available to the main system pump. This fluid is retained to
supply fluid to the auxiliary pump.
Integral fuel tanks on transport aircraft are
supported by the aircraft structure.
Fuel baffles are installed in tanks to prevent ______________________ caused by changes in the attitude of the aircraft.
surging
A reduction in anti-torque thrust will cause the
tail to pivot in the direction of torque rotation around the main rotor axis.
The strength classification of fabrics used in aircraft covering is based on
tensile strength.
You can distinguish between aluminum and aluminum alloy by
testing with a 10 percent solution of caustic soda.
Chattering of the hydraulic pump during operation is an indication
that air is entering the pump
A brake debooster valve is installed in systems where the high pressure of the hydraulic system (3,000 psi) is used to operate brakes
that are designed to work with lower pressure.
When flags such as NAV, HDG, or GS are displayed on an HSI, the indication isv
that function is inoperative.
The correct inflation pressure for an aircraft tire can be obtained from
the aircraft service manual.
A drip gauge may be used to measure
the amount of fuel in the tank.
During inspection of an anticollision light installation for condition and proper operation, it should be determined that
the anticollision light can be operated independently of the position lights.
Very often, repairs to a control surface require static rebalancing of the control surface. Generally, flight control balance condition may be determined by
the behavior of the trailing edge when the surface is suspended from its hinge points.
In troubleshooting an electrical circuit, if an ohmmeter is properly connected across a circuit component and some value of resistance is read,
the component has continuity and is not open.
The green arc on an aircraft temperature gauge indicates
the desirable temperature range.
When installing a chevron-type seal in an aircraft hydraulic cylinder, the open side of the seal should face
the direction of fluid pressure.
Major adjustments on equipment such as regulators, contactors, and inverters are best accomplished outside the airplane on test benches with necessary instruments and equipment. Adjustment procedure should be as outlined by
the equipment manufacturer.
When an air/oil type of landing gear shock strut is used, the initial shock of landing is cushioned by
the fluid being forced through a metered opening.
After a hydraulic accumulator has been installed and air chamber charged, the main system hydraulic pressure gauge will not show a hydraulic pressure reading until
the fluid side of the accumulator has been charged.
A fuel pressure warning switch contacts close and warning light is turned on when
the fuel pressure drops below specified limits.
If all instructions issued by the swaging tool manufacturer are followed when swaging a cable terminal, the resultant swaged terminal strength should be
the full rated strength of the cable.
When balsa wood is used to replace a damaged honeycomb core, the plug should be cut so that
the grain is perpendicular to the skin.
The pin section of an AN/MS connector is normally installed on
the ground side of a circuit.
When a piece of aluminum alloy is to be bent using a minimum radius for the type and thickness of material,
the layout should be made so that the bend will be 90° to the grain of the sheet.
The pressure source for power brakes is
the main hydraulic system.
If too much acetylene is used in the welding of stainless steel,
the metal will absorb carbon and lose its resistance to corrosion.
The strength and stiffness of a properly constructed composite buildup depends primarily on
the orientation of the plies to the load direction.
Internal leakage in a brake master cylinder unit can cause
the pedal to slowly creep down while pedal pressure is applied.
When selecting a welding rod, one of the most important factors to consider is to ensure that
the proper AMS number is used.
When inspecting a control cable turnbuckle for proper installation, determine that
the safety wire ends are wrapped a minimum of four turns around the terminal end shanks.
When repairing a small hole on a metal stressed skin, the major consideration in the design of the patch should be
the shear strength of the riveted joint.
Aircraft instrument value should be marked and graduated in accordance with
the specific aircraft maintenance or flight manual.
During inspection of the terminal strips of an aircraft electrical system, it should be determined that
the terminal studs are anchored against rotation.
Differential control on an aileron system means that
the up travel is more than the down travel.
If the vertical fin of a single-engine, propeller-driven airplane is rigged properly, it will generally be parallel to
the vertical axis but not the longitudinal axis.
A category of plastic material that is capable of softening or flowing when reheated is described as a
thermoplastic.
One of the main advantages of HI-LOK type fasteners over earlier generations is that
they can be installed with ordinary hand tools.
Pin knot clusters are permitted in wood aircraft structure provided
they produce a small effect on grain direction.
The general rule for finding the proper rivet diameter is
three times the thickness of the thickest sheet.
Fuel jettisoning is usually accomplished
through a common manifold and outlet in each wing.
In rotorcraft external-loading, the ideal location of the cargo release is where the line of action passes
through the center of gravity at all times.
When installing transparent plastic enclosures which are retained by bolts extending through the plastic material and self-locking nuts, the nuts should be
tightened to a firm fit, then backed off one full turn.
A helicopter in forward flight, cruise configuration, changes direction by
tilting the main rotor disk in the desired direction.
A resurfaced soldering iron cannot be used effectively until after the working face has been
tinned.
The fuel jettison valve must be designed to allow flight personnel
to close the valve at any time and the fuel must discharge clear of the aircraft.
After repairing or re-covering a rudder, the surface should be rebalanced
to manufacturer's specifications.
The type of electric wire terminals used for most aircraft applications, in addition to providing good current carrying capabilities, are designed primarily
to prevent circuit failure due to terminal disconnection.
A gasket or sealant is used between the antenna mast and fuselage skin
to prevent the entry of moisture.
Fuel-boost pumps are operated
to provide a positive flow of fuel to the engine.
If the extended longitudinal axis of the main landing gear wheel assemblies intersects aft of the aircraft, the wheels can be termed as having
toe-out.
A loud hammering noise in a hydraulic system that has an accumulator usually indicates
too low or no preload in the accumulator.
The preferred location of a VOR antenna on light aircraft is on
top of the cabin with the apex of the V pointing forward
Main rotor blades that do not cone by the same amount during rotation are said to be out of
track.
The function of the condenser in a freon cooling system is to
transfer heat from the freon gas to ambient air.
A radar altimeter determines altitude by
transmitting a signal and receiving back a reflected signal.
When an airplane's primary flight control surfaces are set for a particular phase of flight, such as landing or takeoff, the corresponding control-surface indicating system will show
trim position.
One antenna can be used for the radio range and standard broadcast bands in light aircraft because the
two ranges are close together.
Excessive wear in the shoulder area of an aircraft tire is an indication of
underinflation.
If it is necessary to use an electrical connector where it may be exposed to moisture, the mechanic should
use a special moisture-proof type.
Static inverters are electronic devices that change DC to AC with the
use of an oscillator.
Aircraft brakes requiring a large volume of fluid to operate the brakes generally
use power brake control valves.
When repairing large, flat surfaces with polyester resins, warping of the surface is likely to occur. One method of reducing the amount of warpage is to
use short strips of fiberglass in the bonded repair.
If a fire extinguisher cartridge is removed from a discharge valve, it should be
used only on the original discharge valve assembly.
The hydraulic packing seals used in a landing gear shock strut are
used only with a specific type of fluid.
The correct dihedral angle can be determined by
using a dihedral board and bubble level along the front spar of each wing.
When fuel quantity is measured in pounds instead of gallons, the measurement will be more accurate because fuel volume
varies with temperature change.
To prevent a very rapid extension of an oleo shock strut after initial compression resulting from landing impact,
various types of valves or orifices are used which restrict the reverse fluid flow.
A voltage regulator controls generator output by
varying current flow to generator field coil.
In a hovering helicopter equipped with a tail rotor, directional control is maintained by
varying the pitch of the tail rotor blades.
The internal resistance of a fluid which tends to prevent it from flowing is called
viscosity.
The voltage output of an alternator may be regulated by controlling the
voltage output of the dc exciter.
Phosphate ester-base hydraulic fluid is very susceptible to contamination from
water in the atmosphere
The types of fire-extinguishing agents for aircraft interior fires are
water, carbon dioxide, dry chemical, and halogenated hydrocarbons.
A fire extinguisher container can be checked to determine its charge by
weighing the container and its contents.
A digital fuel totalizer automatically indicates the amount of fuel used, fuel remaining, current rate of consumption, and fuel
weight aboard at takeoff.
Overinflated aircraft tires may cause damage to the
wheel flange.
Glue deterioration in wood aircraft structure is indicated
when a joint has separated and the glue surface shows only the imprint of the wood with no wood fibers clinging to the glue.
One of the main advantages of Skydrol is its
wide operating temperature.
The circuit breaker in the instrument lighting system protects the
wiring from too much current.
A universal propeller protractor used to measure the degrees of aileron travel should be zeroed
with the aileron in the NEUTRAL position.
The main system pressure relief valve in a simple hydraulic system equipped with a power control valve should be adjusted
with the power control valve held in the CLOSED position.
An aircraft oxygen bottle may be considered airworthy if it has been hydrostatically tested and identified
with the test date, DOT number, and serial number stamped on the cylinder near the neck.
In brake service work, the term 'bleeding brakes' is the process of
withdrawing fluid from the system for the purpose of removing air that has entered the system.
If control cables are adjusted properly and the control surfaces tend to vibrate, the probable cause is
worn attachment fittings.
If an airplane equipped with master cylinders and single-disk brakes has excessive brake pedal travel, but the brakes are hard and effective, the probable cause is
worn brake linings.
In some fire-extinguishing systems, evidence that the system has been intentionally discharged is indicated by the absence of a
yellow disk on the side of the fuselage.
Where is information found concerning acceptable species substitutions for wood materials used in aircraft repair?
AC 43.13-1B.
(Refer to Figure 26.) Where is the strongest signal for this antenna?
Above the antenna.
With which system is differential control associated?
Aileron.
How can it be determined that a vapor-cycle cooling system is charged with the proper amount of freon?
Air bubbles in the sight glass disappear.
In a hydraulic system that has a reservoir pressurized with turbine-engine compressor bleed air, which unit reduces the air pressure between the engine and reservoir?
Air pressure regulator.
Other than the manufacturer maintenance manual what other document could be used to determine the primary flight control surface deflection for an imported aircraft that is reassembled after shipment?
Aircraft Type Certificate Data Sheet.
Where may a person look for the information necessary to determine the required markings on an engine instrument?
Aircraft flight manual or aircraft maintenance manual.
Where would you find precise information to perform a symmetry alignment check for a particular aircraft?
Aircraft service or maintenance manual.
What system component aids in the prevention of carburetor icing?
Alcohol injection nozzle.
Which statement about fluids is correct?
All fluids readily transmit pressure.
(Refer to Figure 17.) What is the purpose of the pump crossfeed valve?
Allow operation of engines from one tank.
Which of the following factors must be taken into consideration when determining the wire size to use for an aircraft installation?
Allowable power loss, permissible voltage drop, current carrying capability of the conductor, type of load.
Why are the tubes in deicer boots alternately inflated?
Alternate inflation of deicer boot tubes keeps disturbance of the airflow to a minimum.
When an unpressurized aircraft's static pressure system is leak checked to comply with the requirements of 14 CFR 91.411, what aircraft instrument may be used in lieu of a pitot-static system tester?
Altimeter.
When dope-proofing the parts of the aircraft structure that come in contact with doped fabric, which of the following provide an acceptable protective coating?
Aluminum foil and cellulose tape.
When defueling an aircraft, which of the following must be accomplished?
Always defuel outside the hangar.
In a freon vapor-cycle cooling system, where is cooling air obtained for the condenser?
Ambient air.
What is one check for proper operation of a pitot-static tube heater after replacement?
Ammeter reading.
How are generators rated?
Amperes at rated voltage.
(Refer to Figure 28.) What kind of antenna is this?
An ELT antenna.
What is the principle characteristic of a windshield pneumatic rain removal system?
An air blast forms a barrier that prevents raindrops from striking the windshield surface.
An aircraft magnetic compass is swung to up-date the compass correction card when
An aircraft magnetic compass is swung to up-date the compass correction card when
Which statement is correct regarding an aircraft that is found to be unairworthy after an annual inspection, due to an item requiring a major repair (assuming approved data is used to accomplish the repair)?
An appropriately rated mechanic may accomplish the repair, and an IA may approve the aircraft for return to service.
Which statement is correct when an aircraft has not been approved for return to service after an annual inspection because of several items requiring minor repair?
An appropriately rated mechanic may repair the defects and approve the aircraft for return to service.
What are three methods of anti-icing aircraft windshields?
An electric heating element in the windshield, a heated air circulating system, and windshield wipers and anti-icing fluid.
On an air valve core stem, what indicates high-pressure type?
An embossed letter 'H.'
Aside from an external leak in the line, what will cause parking brakes to continually bleed off pressure?
An internal leak in the master cylinder.
Entrained water in aviation turbine fuel is a hazard because of its susceptibility to freezing as it passes through the filters. What are common methods of preventing this hazard?
Anti-icing fuel additives and fuel heater.
When a landing gear safety switch on a main gear strut closes at liftoff, which system is deactivated?
Antiskid system.
Which statement concerning wood decay is correct?
Any form or amount of decay is not permitted.
(Refer to Figure 20.) What is the minimum circumstance that will cause the landing gear warning horn to indicate an unsafe condition?
Any gear not down and locked, and one throttle retarded.
Which is correct concerning the use of a file?
Apply pressure on the forward stroke, only, except when filing very soft metals such as lead or aluminum.
Which of the following are the major parts of a DC motor?
Armature assembly, field assembly, brush assembly, and end frame.
How should a coaxial cable be routed?
As directly as possible.
How long should you wait after a flight before checking tire pressure?
At least 2 hours (3 hours in hot weather).
Which of the following are found in a laminated integral electrically heated windshield system?
Autotransformer, head control relay, heat control toggle switch, and indicating light.
When charging a vapor-cycle cooling system after evacuation, the low-pressure gauge fails to come out of a vacuum. What is indicated?
Blockage in the system.
Seals used with a mineral-base hydraulic fluid are identified by which color code?
Blue dot or stripe.
Which defect in aircraft finishes may be caused by adverse humidity, drafts, or sudden changes in temperature?
Blushing.
What must be done to an instrument panel that is supported by shock mounts?
Bonding straps must be installed across the instrument mounts as a current path.
What is used in many aircraft to prevent bubbles in the fuel after it leaves the tank when atmospheric pressure is lower than fuel vapor pressure?
Boost pumps.
Washing-in the left wing of a monoplane, for purposes of rigging corrections after flight test, will have what effect on the lift and drag of that wing?
Both drag and lift will increase due to increased angle of attack.
How is a shunt-wound DC generator connected?
Both fields are shunted across the armature.
Which of the following operating mechanisms would be found in a hydraulic pressure gauge?
Bourdon tube.
Where does the breakage of control cable wires occur most frequently?
Breakage usually occurs where cables pass over pulleys and through fairleads.
Which fire-extinguishing agent is considered to be the least toxic?
Bromotrifluoromethane (Halon 1301).
What is the color code for fire extinguisher lines?
Brown.
Which seals are used with petroleum-base hydraulic fluids?
Buna-N.
Which seal/material is used with phosphate ester-base hydraulic fluids?
Butyl rubber.
How may the antiknock characteristics of a fuel be improved?
By adding a knock inhibitor.
The braking action of a Cleveland disk brake is accomplished by compressing a rotating brake disk between two opposite brake linings. How is equal pressure on both sides of the rotating disk assured?
By allowing the caliper to float to automatically equalize as pressure is applied to the rotor.
How is the cabin pressure of a pressurized aircraft usually controlled?
By an automatic outflow valve that dumps all the pressure in excess of the amount for which it is set.
How is a flangeless instrument case mounted in an instrument panel?
By an expanding-type clamp secured to the back of the panel and tightened by a screw from the front of the instrument panel.
How do deicer boots help remove ice accumulations?
By breaking up ice formations.
How can the proper hydraulic fluid to be used in an airplane be determined?
By consulting the aircraft manufacturer's service manual.
How is the cabin pressure of an aircraft maintained in flight?
By controlling the rate of the air flowing out of the cabin.
How is it determined in a master cylinder brake system that all of the air has been purged from the system?
By depressing the brake and noting that the brake is firm and not spongy.
How may the battery replacement date be verified for an emergency locator transmitter (ELT)?
By observing the battery replacement date marked on the outside of the transmitter.
How is the air in a hydraulic accumulator prevented from entering the fluid system?
By physically separating the air chamber from the oil chamber with a flexible or movable separator.
How does acoustic emission testing detect defects in composite materials?
By picking up the 'noise' of any deterioration that may be present.
How is the outlet fuel pressure regulated on a submerged, single-speed, centrifugal-type fuel pump?
By the pump's design and internal clearances
How may the operation of an installed emergency locator transmitter (ELT) be verified during aircraft inspection?
By tuning a communications receiver to the civil emergency frequency and activating the ELT momentarily within five minutes after the hour.
What should be used to inert an integral fuel tank before attempting repairs?
CO(2).
What controls the operation of the cabin pressure regulator?
Cabin altitude.
In what areas of aircraft would you find a carbon monoxide detector?
Cabin and cockpit.
What controls the amount of oxygen delivered to a mask in a continuous-flow oxygen system?
Calibrated orifice
A probe or a series of probes is used in what kind of fuel quantity indicating system?
Capacitor.
What is an important factor in selecting aircraft fuses?
Capacity matches the needs of the circuit.
Which of the following drill bit types work best when drilling an aramid fiber (Kevlar) composite laminate?
Carbide W-point.
Which gas is used for purging an aircraft fuel tank?
Carbon dioxide.
What icing condition may occur when there is no visible moisture present?
Carburetor ice.
Which of the following conditions will determine acceptance of wood with mineral streaks?
Careful inspection fails to reveal any decay.
What is ventilating air used for on a combustion heater?
Carries heat to the places where needed.
Which of the following instrument discrepancies would require replacement of the instrument?
Case leaking, glass cracked, instrument will not zero out, or fogged.
Which instrument condition is acceptable and would not require correction?
Case paint chipped.
What does a rectifier do?
Changes alternating current into direct current.
Which of the following allows fluid to flow unimpeded in one direction but prevents fluid flow in the other direction?
Check valve.
For use in pressurized aircraft, which is generally the least complicated and requires the least maintenance?
Chemical oxygen generator systems.
Which of the following are considered circuit-protective devices that are used in aircraft electrical systems?
Circuit breakers, fuses, and current limiters.
(Refer to Figure 20.) What will illuminate the amber indicator light?
Closing the nose, left and right wheel gear full retract switches.
How does temperature affect fuel weight?
Cold fuel is heavier per gallon.
Which statement about Airworthiness Directives (ADs) is true?
Compliance with an applicable AD is mandatory and must be recorded in the maintenance records.
Any wooden member that has been overstressed is subject to which type of failure?
Compression.
What component might possibly be damaged if liquid refrigerant is introduced into the low side of a vapor-cycle cooling system when the pressure is too high or the outside air temperature is too low?
Compressor.
If it is necessary to enter an aircraft's fuel tank, which procedure should be avoided?
Conduct the defueling and tank purging operation in an air-conditioned building.
Which oxygen system employs a regulator that operates only when the user inhales?
Continuous-flow system.
What is the purpose of a mixing valve in a compressor bleed air air conditioning system?
Control the supply of hot, cool, and cold air.
A transducer in a fuel pressure system serves what function?
Converts fluid pressure directly through a transmitter to the indicator.
A transmitter in a fuel pressure warning system serves what function?
Converts fluid pressure to an electrical signal.
What is normally used to bond noncontinuous stainless steel aircraft components?
Copper jumpers.
What action, if any, should be taken when there is a difference of more than 5 pounds of air pressure in tires mounted as duals?
Correct the discrepancy and enter in the aircraft records.
When used in close proximity to magnetic compasses, cotter pins are made of what material?
Corrosion resisting steel.
When humidity is low, what is likely to occur if unhydrated wash primer is applied to unpainted aluminum and then, about 30 to 40 minutes later, a finish topcoat is applied?
Corrosion.
Which is an acceptable safety device for a castle nut when installed on secondary structures?
Cotter pin.
Which of the following instruments will normally have range markings?
Cylinder head temperature gauge and airspeed indicator.
Which statement about wood decay is correct?
Decay is not acceptable in any form or amount.
Which procedure must be followed when defueling aircraft with sweptback wings?
Defuel the outboard wing tanks first.
Which prevents a sudden loss of pressurization in the event that there is a loss of the pressurization source?
Delivery air duct check valve.
If a high-pressure oxygen cylinder is to be installed in an airplane, it must meet the specifications of the
Department of Transportation.
If it is determined that spongy brake action is not caused by air in the brake system, what is the next most likely cause?
Deteriorated flexible hoses.
What is one disadvantage of using aromatic aviation fuels?
Deteriorates rubber parts.
Which of the following causes of aircraft magnetic compass inaccuracies may be compensated for by mechanics?
Deviation.
Which of the following will cause inaccuracies in a magnetic compass that may be compensated for by an aircraft mechanic?
Deviation.
Which best describes cabin differential pressure?
Difference between the ambient and internal air pressure.
Which of the following are fire precautions which must be observed when working on an oxygen system?
Display 'No Smoking' placards, provide adequate fire-fighting equipment, keep all tools and oxygen servicing equipment free from oil or grease, and avoid checking aircraft radio or electrical systems.
What controls the inflation sequence in a pneumatic deicer boot system?
Distributor valve.
Which of the following connects vacuum to the deicer boots when the system is not in operation, to hold the boots tightly against the leading edges in flight?
Distributor valve.
Which statement is true with respect to an aircraft equipped with hydraulically operated multiple-disk type brake assemblies?
Do not set parking brake when brakes are hot.
When and how is finishing tape applied on a fabric-covered aircraft?
Doped on after the first or second coat of dope.
What is generally the best procedure to use when removing a solid shank rivet?
Drill to the base of the manufactured rivet head with a drill one size smaller than the rivet shank and remove the rivet with a punch.
Which statement regarding an aircraft instrument vacuum system is true?
Dry-type vacuum pumps with carbon vanes are very susceptible to damage from solid airborne particles and must take in only filtered air.
When conducting a tap test on a composite panel, which of the following sounds would indicate delamination?
Dull thud.
The classification for fiberglass reinforcement material that has high resistivity and is the most common is
E-glass.
In the combustion heater, combustion air system, what prevents too much air from entering the heaters as air pressure increases?
Either a combustion air relief valve or a differential pressure regulator
What type of remote-reading fuel quantity indicating system has several probes installed in each fuel tank?
Electronic.
Which aircraft fuel quantity indicating system incorporates a signal amplifier?
Electronic.
Which channel of an autopilot detects changes in pitch attitude of an aircraft?
Elevator.
A typical takeoff warning indication system, in addition to throttle setting, monitors the position of which of the following?
Elevators, speed brake, flaps, and stabilizer trim.
Which must be done before adjusting the relief valve of a main hydraulic system incorporating a pressure regulator?
Eliminate the action of the unloading valve.
Select one means of controlling the fuel temperature on turbine-powered aircraft.
Engine bleed air to a heat exchanger.
To what depth is the mica insulation between the commutator bars of a DC generator undercut?
Equal to the width of the mica.
What mixture may be used as a deicing fluid to remove frost from an aircraft surface?
Ethylene glycol and isopropyl alcohol.
(Refer to Figure 13.) Determine what unit is located immediately downstream of the expansion valve in a freon refrigeration system.
Evaporator coils.
How often should standard weight high-pressure oxygen cylinders be hydrostatically tested?
Every 5 years.
Which of the following is most likely to cause thermal runaway in a nickel-cadmium battery?
Excessive current draw from the battery.
Many brake types can be adapted to operate mechanically or hydraulically. Which type is not adaptable to mechanical operation?
Expander-tube type.
At which component in an air-cycle cooling system does air undergo a pressure and temperature drop?
Expansion turbine.
Where does the last stage of cooling in an air-cycle air conditioning system occur?
Expansion turbine.
What component in a vapor-cycle cooling system would most likely be at fault if a system would not take a freon charge?
Expansion valve.
Which statement best describes magnesium welding?
Filler rod should be the same composition as base metal.
What should be used to remove flux from an aluminum tank after welded repairs?
Five percent solution of nitric or sulfuric acid.
Which is a characteristic of petroleum-base hydraulic fluid?
Flammable under normal conditions.
What is a method used for restoring generator field residual magnetism?
Flash the fields.
Which of the following provides manual maneuverability of the aircraft while the autopilot is engaged?
Flight controller.
On modern large aircraft, what electronic device typically monitors flight parameters and performs autopilot functions?
Flight management computer.
Which of the following, when added to wet resins, provide strength for the repair of damaged fastener holes in composite panels?
Flox and chopped fibers.
Which of the following indications occur during a normal operational check of a pneumatic deicer system?
Fluctuating readings on the pressure gauge and relatively steady readings on the vacuum gauge.
What should be checked when a shock strut bottoms during a landing?
Fluid level.
Where can information be obtained about the compatibility of fire-resistant hydraulic fluid with aircraft materials?
Fluid manufacturer's technical bulletins.
What characteristics of the installation of a rigid antenna on a vertical stabilizer should be evaluated?
Flutter and vibration.
Machine-sewn seams in aircraft covering fabrics may be of which of the following types?
Folded-fell, French-fell, or plain lapped.
In an autopilot, which signal nullifies the input signal to the ailerons?
Follow-up signal.
Select the alternative which best describes the function of the flute section of a twist drill.
Forms the cutting edges of the drill point.
What type of selector valve is one of the most commonly used in hydraulic systems to provide for simultaneous flow of fluid into and out of a connected actuating unit?
Four-port, closed-center valve.
How many fabric thicknesses will be found in a French-fell seam?
Four.
What type of flap system increases the wing area and changes the wing camber?
Fowler flaps.
Resistance-type temperature indicators using Wheatstone bridge or ratiometer circuits may be used to indicate the temperatures of which of the following?
Free air, carburetor air, coolant (engine), and oil temperature.
What is required when operating two aircraft AC generators in parallel?
Frequency and voltage must both be equal.
What is indicated by a black 'smoky' residue streaming back from some of the rivets on an aircraft?
Fretting corrosion is occurring between the rivets and the skin.
What is the dielectric (nonconducting material) in a capacitance-type fuel quantity indicating system?
Fuel and air in the tank.
Where is fuel pressure taken for the pressure warning signal on most aircraft engines?
Fuel pressure line of the carburetor.
Which of the following would give the first positive indication that a change-over from one fuel tank to another is needed?
Fuel pressure warning.
What method is used on turbine-powered aircraft to determine when the condition of the fuel is approaching the danger of forming ice crystals?
Fuel temperature indicator.
Which of the following precautions is most important during refueling operations?
Fuel to be used must be appropriately identified.
Exposure to and/or storage near which of the following is considered harmful to aircraft tires?
Fuel, oil, ozone, electrical equipment, hydraulic fluid, and solvents.
Which repair would require a landing gear retraction test?
Gear downlock microswitch.
When air samples contain carbon monoxide, portable carbon monoxide detectors containing yellow silica gel will turn which color?
Green.
What safety device is actuated by the compression and extension of a landing gear strut?
Ground safety switch.
What component is the sensing device in an electromechanical autopilot system?
Gyro.
The aluminum alloys used in aircraft construction are usually hardened by which method?
Heat treatment.
Which is a characteristic of synthetic-base hydraulic fluid?
High flash point.
What is the principal advantage of the series-wound DC motor?
High starting torque.
Which of the following are generally characteristic of aramid fiber (Kevlar) composites?
High tensile strength and flexibility.
What is the condition of the refrigerant as it leaves the condenser of a vapor-cycle cooling system?
High-pressure liquid.
What is the condition of the refrigerant as it enters the condenser of a vapor-cycle cooling system?
High-pressure vapor.
What should be used to melt the ice in a turbine engine if the compressor is immobile because of ice?
Hot air.
Which statement is true regarding the inspection of a stressed skin metal wing assembly known to have been critically loaded?
If genuine rivet tipping has occurred, groups of consecutive rivet heads will be tipped in the same direction.
Which is true regarding the ground check of a flap operating mechanism which has just been installed?
If the time required to operate the mechanism decreases with successive operations, it indicates the air is being worked out of the system.
Which of the following are benefits of using microballoons when making repairs to laminated honeycomb panels?
Improved strength-to-weight ratio, less density, and lower stress concentrations.
How should a voltmeter be connected?
In parallel with the load.
Which of the following is one advantage of HI-LOK fasteners?
Inability to be over-torqued.
What condition would most likely cause excessive fluctuation of the pressure gauge when the hydraulic pump is operating?
Inadequate supply of fluid.
Which of the following are some uses for a DC selsyn system?
Indicate the position of retractable landing gear, cowl flaps position, cooler door position, fuel quantity, and position of wing flaps.
Which of the following must be accomplished when installing an anticollision light?
Install a switch independent of the position light switch.
Which procedure should you use if you find a vacuum-operated instrument glass loose?
Install another instrument.
Which should be accomplished before jacking an aircraft?
Install critical stress panels or plates.
What is the most accurate type of frequency measuring instrument?
Integrated circuit chip having a clock circuit.
Microbial growth is produced by various forms of microorganisms that live and multiply in the water interfaces of jet fuels. Which of the following could result if microbial growth exists in a jet fuel tank and is not corrected?
Interference with fuel flow, interference with fuel quantity indicators, and electrolytic corrosive action in a metal tank.
Cases for electrically operated instruments are made of
Iron or steel cases.
What is the primary purpose of the crossfeed system?
It allows any tank to supply fuel to any engine.
Which statement best describes magnesium welding? 1
It can be welded successfully using the same type of joints that are used for aluminum. 1
What is the purpose of the free-wheeling unit in a helicopter drive system?
It disengages the engine from the main rotor when engine RPM is less than rotor RPM.
Why should a carburizing flame be avoided when welding steel?
It hardens the surface.
Which statement concerning an electronic capacitance-type fuel quantity indicating system is true?
It has no moving parts in the tank.
What is the advantage of a circuit breaker when compared to a fuse?
It is resettable and reusable.
Why is the capacitance fluid quantity indicating system more accurate in measuring fuel level than a mechanical type?
It measures by weight instead of volume.
What is the purpose of a float-operated transmitter installed in a fuel tank?
It sends an electric signal to the fuel quantity indicator.
Why is the main fuel strainer located at the lowest point in the fuel system?
It traps any small amount of water that may be present in the fuel system
Why should a chemical rain repellant not be used on a dry windshield?
It will restrict visibility.
What is the advantage of a current limiter?
It will take overload for a short period.
Why are jet fuels more susceptible to water contamination than aviation gasoline?
Jet fuel has a higher viscosity than gasoline.
Which statement concerning soldering is correct?
Joints in electric wire to be soldered should be mechanically secure prior to soldering.
Where are the heating elements located on most aircraft with electrically heated windshields?
Laminated in the glass.
Which of the following conditions is most likely to cause the landing gear warning signal to sound?
Landing gear not locked down and throttle retarded.
Which motor would be most likely to have an armature brake?
Landing light retraction motor.
The elevator channel of an autopilot controls the aircraft about which axis of rotation?
Lateral.
What is the color and orientation of the position lights for navigation on civil airplanes?
Left side, red; right side, green; rear aft, white.
Which of the following should be accomplished in the installation of aircraft wiring?
Locate the bundle above flammable fluid lines and securely clamp to structure.
Which parts of a semi-monocoque fuselage prevent tension and compression from bending the fuselage?
Longerons and stringers.
Which section of a turbine engine provides high pressure bleed air to an air cycle machine for pressurization and air conditioning?
Low or high pressure compressor.
What is a cause of generator brush arcing?
Low spring tension.
Which of the following lists only desirable properties of a good hydraulic fluid that has chemical stability?
Low viscosity, high flash point, high fire point.
What is the condition of the refrigerant as it enters the evaporator of a vapor-cycle cooling system?
Low-pressure liquid.
What is the condition of the refrigerant as it leaves the evaporator of a vapor-cycle cooling system?
Low-pressure vapor
What is the fixed line mark attached to the compass bowl of a magnetic compass called?
Lubber line.
When making repairs to fiberglass, cleaning of the area to be repaired is essential for a good bond. The final cleaning should be made using
MEK (methyl ethyl ketone).
Which rivets should be selected to join two sheets of .032-inch aluminum?
MS20470AD-4-4
What is the purpose of the torque links attached to the cylinder and piston of a landing gear oleo strut?
Maintain correct wheel alignment.
Which of the following would be most useful to locate and troubleshoot an internal fuel leak in an aircraft fuel system?
Maintenance manual diagrams and descriptions.
When selecting hardware for attaching bonding connections to an aircraft structure, which of the following should be considered?
Mechanical strength, ease of installation, amount of current to be carried.
What protection to wires and cables does conduit provide when used in aircraft installations?
Mechanical.
What type of instrument is used for measuring very high values of resistance?
Megohmmeter.
A filter incorporating specially treated cellulose paper is identified as a
Micronic filter.
Electrical connectors used in the aircraft assemblies should meet which of the following specifications?
Military Specifications (MS).
What purpose does flux serve in welding aluminum?
Minimizes or prevents oxidation.
Which characteristics apply to aircraft hydraulic systems?
Minimum maintenance requirements, lightweight, and simple to inspect.
What is the main cause of contamination in a gaseous oxygen system?
Moisture.
Which rivet is used for riveting nickel-steel alloys?
Monel.
What is the main purpose of a servo in an autopilot system?
Move the control surface as commanded.
What is used to flush a system normally serviced with MIL-H-5606 hydraulic fluid?
Naphtha or varsol.
What component of a pressurization system prevents the cabin altitude from becoming higher than airplane altitude?
Negative pressure relief valve.
How many of these seals are used with petroleum-base hydraulic fluids?
Neoprene, Buna-N.
Which statement is true regarding a cantilever wing?
No external bracing is needed.
Which of the following copper electrical cable sizes should be selected to replace a No. 6 aluminum electrical cable?
No. 6.
What will occur if an aircraft attitude is changed by its autopilot system in order to correct for an error and the involved control surfaces are returned to streamline by the time the aircraft has reached its correct position?
Normal operation.
Which of the following functions does a skid control system perform?
Normal skid control, fail safe protection, locked wheel skid control, touchdown protection.
Which of the following is the most commonly used seal to prevent internal and external leakage in both directions of a hydraulic unit?
O-ring.
When a vapor-cycle cooling system is not in operation, what is an indication that the system is leaking freon?
Oil seepage.
Which statement is true regarding paint system compatibility?
Old wash primer coats may be overcoated directly with epoxy finishes.
Where is the landing gear safety switch usually located?
On the main gear shock strut.
How many engine driven fuel pumps per engine are required for engines requiring fuel pumps?
One fuel pump for each engine.
What is the minimum distance allowed between a fuel tank and the fire wall separating the engine?
One-half inch.
How would the air pressure charge in the accumulator be determined if the engine is inoperative, but the system still has hydraulic pressure?
Operate a hydraulic unit slowly and note the pressure at which a rapid pressure drop begins as it goes toward zero.
What type of valve in an aircraft hydraulic system permits fluid to flow freely in one direction, but restricts the rate at which fluid is allowed to flow in the other direction?
Orifice check valve.
What type of packings should be used in hydraulic components to be installed in a system containing Skydrol?
Packing materials made for ester-base fluids.
Where should the flux be applied when oxyacetylene welding aluminum?
Painted on the surface to be welded and applied to the welding rod.
The requirements for testing and inspection of instrument static systems required by 14 CFR 91.411 are contained in
Part 43, appendix E.
If a wire is installed so that it comes in contact with some moving parts, what protection should be given the wire?
Pass through conduit.
What is the purpose of a compensating port or valve in a brake master cylinder of an independent brake system?
Permits the fluid to flow toward or away from the reservoir as temperature changes.
Smoke in the cargo and/or baggage compartment of an aircraft is commonly detected by which instrument?
Photoelectric cell.
When riveting dissimilar metals together, what precautions must be taken to prevent an electrolytic action?
Place a protective separator between areas of potential electrical difference.
What method would be used to check for internal leakage of a fuel valve without removing the valve from the aircraft?
Place the valve in the OFF position, drain the strainer bowl, and with boost pump on, watch to see if fuel flows to the strainer bowl.
Which properly applied finish topcoat is the most durable and chemical resistant?
Polyurethane.
What is used in some oxygen systems to change high cylinder pressure to low system pressure?
Pressure reducer valve.
What device in a hydraulic system with a constant-delivery pump allows circulation of the fluid when no demands are on the system?
Pressure regulator.
In a high-pressure oxygen system, if the pressure reducer fails, what prevents high-pressure oxygen from entering the system downstream?
Pressure relief valve.
In a gaseous oxygen system, which of the following are vented to blow out plugs in the fuselage skin?
Pressure relief valves.
What test is used to determine the serviceability of an oxygen cylinder?
Pressure test with water.
What unit is generally used to actuate the fuel pressure warning system?
Pressure-sensitive mechanism.
What unit would be adjusted to change the fuel pressure warning limits?
Pressure-sensitive mechanism.
When purging a freon air conditioning system, it is important to release the charge at a slow rate. What is the reason for the slow-rate discharge?
Prevent excessive loss of refrigerant oil.
What is the purpose of using backup rings with O-rings in hydraulic systems above 1,500 psi?
Prevent high pressure from extruding the seal between the moving and stationary part.
What is the main purpose of a pressurized reservoir in a hydraulic system?
Prevent hydraulic pump cavitation.
What is the ratio of turns between the primary coil winding and the secondary coil winding of a transformer designed to triple its input voltage?
Primary will have one-third as many turns as its secondary.
What precaution, if any, should be taken to prevent corrosion inside a repaired metal honeycomb structure?
Prime the repair with a corrosion inhibitor and seal from the atmosphere.
How are changes in direction of a control cable accomplished?
Pulleys.
What safety device is usually located between the driving unit and hydraulic pump drive shaft?
Pump drive coupling shear section.
Excluding lines, which components are required to make up a simple hydraulic system?
Pump, reservoir, selector valve, and actuator.
What is the frequency of an alternator dependent upon?
RPM.
How should you determine the amount of oxygen in a portable, high-pressure cylinder?
Read the pressure gauge mounted on the cylinder.
In an AC circuit with no phase lead or lag, which is true?
Real power equals apparent power.
What unit in a vapor-cycle cooling system serves as a reservoir for the refrigerant?
Receiver-dryer.
Landing gear warning systems usually provide which of the following indications?
Red light for unsafe gear; green light for gear down; no light for gear up
Which of the following instrument discrepancies could be corrected by an aviation mechanic?
Red line missing, mounting screws loose, case paint chipped, or leaking at line B nut.
Petroleum-base hydraulic fluid is which color?
Red.
Which of the following is not one of the purposes of interpoles in a generator?
Reduce field strength.
Why are aluminum plates 1/4 inch or more thick usually preheated before welding?
Reduces internal stresses and assures more complete penetration
What flight safety-related advantage does a pressure fueling system provide?
Reduces the chances for fuel contamination.
What function does the absolute pressure regulator perform in the pneumatic power system?
Regulates the compressor inlet air to provide a stabilized source of air for the compressor.
Which of the following tests can determine an aviation gasoline's tendency to vapor lock?
Reid vapor pressure test.
A close inspection of a fusible plug reveals the core has experienced some deformation. What is the appropriate maintenance procedure?
Replace all the fusible plugs.
(Refer to Figure 19). Which repair should be made if the gear switch was placed in UP position and the gear does not retract?
Replace electrical wire No. 12.
What is used to slow the drying time of some finishes and to prevent blush?
Retarder.
How can the direction of rotation of a DC electric motor be changed?
Reverse the electrical connections to either the field or armature windings.
Electric wire terminals for most aircraft applications must be what type?
Ring.
Which of the following need not be considered when determining minimum rivet spacing?
Rivet length.
Which of the following may be used for the repair of fuel leaks on most integral fuel tanks?
Riveting and resealing.
The classification for high tensile strength fiberglass used in aircraft structures is
S-glass.
Which of the following can normally be welded without adversely affecting strength?
SAE 4130 chrome/molybdenum tubing.
Select the valve used in a hydraulic system that directs pressurized fluid to one end of an actuating cylinder and simultaneously directs return fluid to the reservoir from the other end.
Selector.
In which control element of an autopilot system is an attitude indicator?
Sensing.
Which type of DC generator is not used as an airplane generator?
Series wound.
What component of an autopilot system applies torque to the control surfaces of an aircraft?
Servo.
What type loads cause the most rivet failures?
Shear.
(Refer to Figure 19.) Upon completion of the landing gear extension cycle, the green light illuminated and the red light remained lit. What is the probable cause?
Short in the up limit switch.
What is commonly used to connect an emergency source of power, and at the same time disconnect the normal hydraulic source from critical parts of a landing gear or wheel braking system for operation (usually when the normal source system fails)?
Shuttle valve.
What are the four general types of fuel quantity gauges?
Sight glass, mechanical, electrical, and electronic.
What kind of switch should you install in a single wire circuit that required the switch to be manually held in the ON position?
Single-pole, single-throw (SPST), two-position normally open (NO).
Which of the following is adversely affected by atmospheric humidity if left unprotected?
Skydrol hydraulic fluid.
What type of fuel-booster pump requires a pressure relief valve?
Sliding vane.
How should a welding torch flame be adjusted to weld stainless steel?
Slightly carburizing.
Why is it generally necessary to jack an aircraft indoors for weighing?
So that air currents do not destabilize the scales.
What is the most common method of cementing transparent plastics?
Soak method.
What may be used to clean deicer boots?
Soap and water.
What physical factors are involved in the aspect ratio of airplane wings?
Span and chord.
What type of oil is suitable for use in vapor-cycle cooling system?
Special high grade refrigeration oil.
How should the splices be arranged if several are to be located in an electrical wire bundle?
Staggered along the length of the bundle.
As a general rule, which statement is true regarding fuel leaks?
Stains, seeps, and heavy seeps (in addition to running leaks), are considered flight hazards when located in unvented areas of the aircraft.
Where is the generator rating and performance data located?
Stamped on the generator data plate.
Which of the following is a hazard associated with sanding on fabric covered surfaces during the finishing process?
Static electricity buildup.
What is the recommended practice for cleaning a fuel tank before welding?
Steam clean the tank interior.
Which of the following are generally characteristic of carbon/graphite fiber composites?
Stiffness, high compressive strength, and corrosive effect in contact with aluminum.
Components containing phosphate ester-base hydraulic fluid may be cleaned with
Stoddard solvent.
What is the function of a cam incorporated in a nose gear shock strut?
Straightens the nosewheel.
Which of the following regulates the vacuum of the air pump to hold the deicing boots deflated when the pneumatic deicing system is off?
Suction relief valve.
What should be used to protect wires from chafing when they must pass through bulkheads, firewalls, ribs, etc.?
Suitable grommet.
Which is considered a good practice concerning the inspection of heating and exhaust systems of aircraft utilizing a jacket around the engine exhaust as a heat source?
Supplement physical inspections with periodic operational carbon monoxide detection tests.
Hydraulic system accumulators serve which of the following functions?
Supplement the system pump when demand is beyond the pump's capacity and store power for limited operation of components if the pump is not operating.
If an aircraft hydraulic system requires mineral-base hydraulic fluid, but phosphate ester-base hydraulic fluid is used, what will be the effect on the system?
System will be contaminated, fluids will not blend, and the seals will fail
Which part of 2017-T36 aluminum alloy indicates the temper designation?
T36.
If a new safety belt is to be installed in an aircraft, the belt must conform to the strength requirements in which document?
TSO C22.
What may be used as a lubricant on oxygen system tapered pipe thread connections?
Teflon tape.
What is the minimum bend radius for an electrical wire bundle?
Ten times the outside diameter of the bundle.
What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called?
Bleeder.
Which of the following is necessary to effectively troubleshoot a fuel pressure warning system?
The manufacturer's maintenance manuals.
When installing an instrument in an aircraft, who is responsible for making sure it is properly marked?
The mechanic installing the instrument.
What is the minimum edge distance allowed for aluminum alloy single lap sheet splices containing a single row of rivets as compared to a joint with multiple rows, all rivets being equal in diameter?
The minimum edge distance for the single row is equal to that for the multiple row.
The strength of the core of an electromagnet depends upon the material from which it is constructed and which of the following?
The number of turns of wire in the coil and the amount of current (amperes) passing through the coil.
What happens to the output of a constant-displacement hydraulic pump when the hydraulic system pressure regulator diverts the fluid from the system to the reservoir?
The output pressure reduces, but the volume remains the same.
What is the operating principle of the sensing device used in an autopilot system?
The relative motion between a gyro and its supporting system.
What must each fuel quantity indicator be calibrated to read during level flight when the quantity of fuel remaining is equal to the unusable fuel supply?
Zero.
Which is an identifying characteristic of acrylic plastics?
Zinc chloride will have no effect.
An O-ring intended for use in a hydraulic system using MIL-H-5606 (mineral base) fluid will be marked with
a blue stripe or dot.
Integrated drive generators (IDG) employ a type of high output AC generator that utilizes
a brushless system to produce current.
In some aircraft with several fuel tanks, the possible danger of allowing the fuel supply in one tank to become exhausted before the selector valve is switched to another tank is prevented by the installation of
a fuel pressure warning signal system.
The angle of incidence is that acute angle formed by
a line parallel to the wing chord and a line parallel to the longitudinal axis of the aircraft.
A welding torch backfire may be caused by
a loose tip.
An aircraft pneumatic system, which incorporates an engine-driven multistage reciprocating compressor, also requires
a moisture separator.
In cases of elongated bolt holes in a wood spar or cracks in the vicinity of boltholes,
a new section of spar should be spliced in or the spar replaced entirely.
An aircraft's integral fuel tank is
a part of the aircraft structure.
The rotor in a Magnesyn remote indicating system uses
a permanent magnet.
The installation of CherryMax and Olympic-Lok rivets is accomplished by utilizing
a pulling tool.
If hydraulic fluid is released when the air valve core of the accumulator is depressed, it is evidence of
a ruptured diaphragm or leaking seals.
One purpose of a growler test is to determine the presence of
a shorted armature.
Oil canning of the sides of aluminum or steel electrical junction boxes is considered to be
a shorting hazard.
A fully charged hydraulic accumulator provides
a source for additional hydraulic power when heavy demands are placed on the system.
The basic air-cycle cooling system consists of
a source of compressed air, heat exchangers, and a turbine.
Aircraft which operate only AC generators (alternators) as a primary source of electrical power normally provide current suitable for battery charging through the use of
a stepdown transformer and a rectifier.
Antiskid braking systems are generally armed by
a switch in the cockpit.
When necessary during operation, CSD disconnect is usually accomplished by
a switch in the cockpit.
The primary purpose of a takeoff warning system is to alert the crew that a monitored flight control is not properly set prior to takeoff. The system is activated by
a thrust lever.
A CSD unit drives a generator through the use of
a variable hydraulic pump and hydraulic motor.
Filing or grinding a weld bead is considered to be
a way to bring about strength reduction in joint
Dutch roll, a combination yawing and rolling oscillation that affects many sweptwing aircraft, is counteracted with
a yaw damper system.
Flapper valves are used in fuel tanks to
act as check valves.
Edge notching is generally recommended in butt welding above a certain thickness of aluminum because it
aids in getting full penetration of the metal and prevents local distortion.
Hot compressor bleed air operates the conditioned air system on some turbine aircraft, cold air supplied by the
air cycle air conditioning.
A pilot reports the right brake on an aircraft is spongy when the brake pedal is depressed in a normal manner. The probable cause is
air in the brake hydraulic system.
Chatter in a hydraulic system is caused by
air in the system.
When servicing aircraft hydraulic systems, use the type fluid specified in the
aircraft manufacturer's maintenance manual or instruction plate affixed to the unit.
