FAA Airframe Mechanic Written Exam — Questions and Answers

Question 1: When performing a sheet metal repair, what is the primary purpose of stop-drilling the ends of a crack?

To mark the location of the crack for inspection.
To provide a starting point for a saw or file.
To relieve stress and prevent the crack from propagating. (Correct answer)
To create a hole for a temporary fastener.

Correct answer: To relieve stress and prevent the crack from propagating.

Stop-drilling involves drilling a small hole at the tip of a crack. This technique distributes the stress concentration from the sharp point of the crack over the larger area of the drilled hole, which effectively blunts the crack and prevents it from spreading further under load and vibration.

Question 2: What is the primary cause of hot section deterioration in a turbine engine?

High compressor inlet temperatures
Oil contamination of the turbine blades
Vibration from compressor imbalance
Thermal cycling and oxidation from extreme combustion temperatures (Correct answer)

Correct answer: Thermal cycling and oxidation from extreme combustion temperatures

Combustion temperatures far exceeding blade material limits cause oxidation, thermal fatigue cracking, and erosion in the turbine hot section.

Question 3: What is the purpose of a 'sector' (or quadrant) in a flight control system?

It converts linear cable motion to rotational motion at the control surface (Correct answer)
It provides a pulley for cable direction changes
It limits maximum surface deflection
It amplifies control input force

Correct answer: It converts linear cable motion to rotational motion at the control surface

A sector (quadrant) is a curved drum or arc that converts the linear pull of a cable into rotational movement to deflect a control surface.

Question 4: During a walk-around inspection, a pilot reports that the nose gear of a tricycle-gear aircraft is not centered after engine shutdown. What component is designed to straighten the nose wheel before it enters the wheel well during retraction?

The shimmy damper.
The torque links.
Internal centering cams or an external roller. (Correct answer)
The squat switch.

Correct answer: Internal centering cams or an external roller.

Retractable nose gear systems incorporate a centering device, often internal cams or an external centering roller, to ensure the wheel is aligned fore and aft before retraction. This prevents the tire from striking the sides of the wheel well and causing damage.

Question 5: When performing a landing gear retraction test, the aircraft should be placed on jacks in a specific configuration. What is a critical reason for this procedure?

To simulate the air loads that the gear experiences in flight.
To ensure the squat switches are in the 'in-flight' or 'unloaded' position. (Correct answer)
To allow for easier access to the brake system for inspection.
To reduce the hydraulic pressure required to cycle the gear.

Correct answer: To ensure the squat switches are in the 'in-flight' or 'unloaded' position.

Placing an aircraft on jacks allows the landing gear struts to fully extend, releasing the compression on the squat switches (weight-on-wheels switches). This moves the switches into their 'in-flight' configuration, which closes the electrical circuit and allows the landing gear retraction system to be operated from the cockpit for testing purposes.

Question 6: While performing a tap test on a composite honeycomb control surface, an inspector notes a distinct change in sound from a sharp, ringing noise to a dull thud in a localized area. This sound change most likely indicates:

A properly bonded and solid internal structure.
Normal variation in sound due to an internal rib or spar.
Delamination or a disbond between the skin and the core. (Correct answer)
A surface scratch that has penetrated the top layer of paint.

Correct answer: Delamination or a disbond between the skin and the core.

A tap test relies on acoustic feedback. A well-bonded, solid structure produces a clear, ringing sound. A dull, dead, or "thud" sound indicates a void or separation, such as a delamination or disbond, which absorbs the sound energy instead of transmitting it.

Question 7: What is the significance of Appendix C versus Appendix O in FAR Part 25 for ice protection system certification?

Appendix C is for anti-ice systems; Appendix O is for deice systems only
Appendix C defines the traditional icing envelope; Appendix O defines the SLD icing envelope (Correct answer)
Appendix C covers structural loads; Appendix O covers electrical system failures
Appendix C applies to jets; Appendix O applies to turboprops only

Correct answer: Appendix C defines the traditional icing envelope; Appendix O defines the SLD icing envelope

Appendix C defines the classical continuous maximum and intermittent maximum icing envelopes, while Appendix O (added later) defines the SLD (freezing rain and freezing drizzle) icing envelope.

Question 8: What is the function of a fuel strainer (gascolator) installed in an aircraft fuel system?

To boost fuel pressure to the carburetor
To remove water and debris from fuel before it reaches the engine (Correct answer)
To measure fuel flow rate to the engine
To control the fuel-to-air mixture ratio

Correct answer: To remove water and debris from fuel before it reaches the engine

A fuel strainer or gascolator filters out water, sediment, and particulate contaminants to protect the carburetor and engine from damage.

Question 9: What information is found on a sheet metal part's material callout such as '2024-T3 ALCLAD .040'?

Alloy, treatment, application area code, and thickness in millimeters
Alloy series, temper, surface finish code, and weight per square foot
Alloy, temper, cladding type, and sheet thickness in inches (Correct answer)
Alloy family, heat code, layer count, and thickness in gauge number

Correct answer: Alloy, temper, cladding type, and sheet thickness in inches

The callout '2024-T3 ALCLAD .040' specifies the aluminum alloy (2024), temper (T3), that it has alclad corrosion-resistant cladding, and the sheet thickness is 0.040 inches.

Question 10: During an annual inspection, a mechanic finds that a required placard is missing from the cockpit. What action must be taken before returning the aircraft to service?

The aircraft may fly until the next 100-hour inspection
Apply a temporary written note in the same location
Note it in the logbook and advise the owner to order a replacement
Replace or reproduce the placard with the correct information per the TCDS or AFM (Correct answer)

Correct answer: Replace or reproduce the placard with the correct information per the TCDS or AFM

Required placards are part of the type design; a missing placard must be replaced with one that meets the approved data before returning the aircraft to service.

Question 11: Which of the following is the primary purpose of incorporating dihedral in an aircraft's wing design?

To increase the wing's overall lift coefficient at high angles of attack.
To enhance lateral stability around the roll axis. (Correct answer)
To improve longitudinal stability around the pitch axis.
To decrease parasitic drag during high-speed cruise flight.

Correct answer: To enhance lateral stability around the roll axis.

Dihedral is the upward angle of the wings from the horizontal. Its primary purpose is to provide positive lateral stability (stability in roll). When an aircraft with dihedral is disturbed and one wing drops, a sideslip occurs. This sideslip causes the lower wing to experience a greater angle of attack and generate more lift, creating a rolling moment that tends to restore the aircraft to a wings-level attitude.

Question 12: What is the maximum allowable fuel tank leakage per FAA standards?

Any minor leakage is acceptable if the fuel cap is secure
Up to three drops per minute is acceptable during normal operation
Seepage (wetness without drops forming) is acceptable; dripping is not (Correct answer)
Zero leakage is permitted under any condition

Correct answer: Seepage (wetness without drops forming) is acceptable; dripping is not

FAA standards distinguish between 'seepage' (fuel wetness with no drops) which is acceptable, and 'leakage' where drops form, which is not airworthy.

Question 13: What does the term 'return to service' specifically mean in the context of 14 CFR Part 43?

The aircraft has been refueled and is ready for the next flight
The aircraft has been repositioned from the hangar to the ramp
An authorized individual has approved the aircraft as airworthy after maintenance (Correct answer)
The aircraft has completed its scheduled annual inspection

Correct answer: An authorized individual has approved the aircraft as airworthy after maintenance

Return to service occurs when an authorized person approves and signs off that the aircraft is airworthy following maintenance, preventive maintenance, or alteration.

Question 14: During final rigging check of a manual flight control system, the mechanic applies force to deflect the aileron and then releases it. The aileron should:

Stay in the deflected position due to control lock friction
Return to neutral only when the opposite aileron is deflected
Vibrate briefly and then center automatically via the trim tab
Return to the neutral position and remain there without binding or excessive friction (Correct answer)

Correct answer: Return to the neutral position and remain there without binding or excessive friction

After deflection, flight controls must return to neutral under system forces (springs, weight, aerodynamic loads) and remain there without binding, sticking, or excessive breakout force.

Question 15: What is the function of a jury strut on a semi-cantilever wing?

Carries the primary bending load from the wing to the fuselage
Connects the wing leading edge to the forward fuselage
Prevents the interplane strut from bowing under compression loads (Correct answer)
Transfers fuel load to the center section

Correct answer: Prevents the interplane strut from bowing under compression loads

A jury strut braces the interplane or wing strut at its midpoint to prevent bowing or buckling under compressive loads.

Question 16: A technician is performing a static balance check on an aileron that has just been repainted. The procedure involves supporting the aileron on a knife-edge fixture at its hinge line. Which of the following conditions indicates the aileron is properly balanced?

The leading edge slowly drops until it rests on the fixture.
The aileron oscillates for several seconds before settling with the trailing edge down.
The trailing edge consistently rises to a 15-degree angle.
The aileron remains in a horizontal position or exhibits a slight nose-down tendency. (Correct answer)

Correct answer: The aileron remains in a horizontal position or exhibits a slight nose-down tendency.

Proper static balance requires the control surface's center of gravity (CG) to be at or slightly ahead of the hinge line. When placed on a knife-edge at the hinge line, a balanced surface will remain horizontal or show a slight tendency to be nose-down. A trailing-edge-heavy condition (underbalance) is undesirable as it can lead to control surface flutter at high speeds.

Question 17: Stress corrosion cracking in high-strength aluminum alloys is most likely to initiate when:

Sustained tensile stress acts on the material in a corrosive environment (Correct answer)
Compressive residual stresses are introduced by shot peening
The alloy is exposed to salt spray during ground operations
The material is heated above its recrystallization temperature

Correct answer: Sustained tensile stress acts on the material in a corrosive environment

Stress corrosion cracking requires the simultaneous combination of sustained tensile stress and a corrosive environment to initiate and propagate.

Question 18: What is the purpose of fuel tank baffles installed inside aircraft fuel tanks?

To allow the fuel quantity transmitter to read accurately
To prevent fuel surge and maintain fuel outlet coverage during flight maneuvers (Correct answer)
To increase internal fuel tank pressure during climb
To filter large debris before fuel reaches the boost pump

Correct answer: To prevent fuel surge and maintain fuel outlet coverage during flight maneuvers

Fuel tank baffles are internal partitions that prevent fuel from surging away from the outlet during maneuvers, ensuring continuous uninterrupted fuel flow to the engine.

Question 19: During a landing gear extension sequence, the landing gear doors must open fully before the gear begins to extend. Which type of valve is specifically designed to control the sequence of operations between two different branches of a hydraulic circuit?

Selector valve
Relief valve
Check valve
Sequence valve (Correct answer)

Correct answer: Sequence valve

A sequence valve is designed to control the order of operations in a hydraulic system. It ensures that one action, like opening the gear doors, is completed before another action, like extending the landing gear, begins.

Question 20: What inspection is required for a fuel tank after it has been repaired or resealed?

A visual inspection of the exterior seams only
A dye penetrant inspection of all interior seams
An ultrasonic thickness test of all tank walls
A pressure test to verify fuel-tight integrity and structural soundness (Correct answer)

Correct answer: A pressure test to verify fuel-tight integrity and structural soundness

After repair or resealing, fuel tanks must be pressure tested to confirm they are fuel-tight and structurally sound before being returned to service per the maintenance manual.

Question 21: The rigging pin (alignment pin) used during assembly of a control surface to the airframe is intended to:

Hold components in precise alignment for installation of fasteners (Correct answer)
Permanently lock the control surface in neutral position
Replace hinge bolts during ferry flights
Balance the control surface during final rigging

Correct answer: Hold components in precise alignment for installation of fasteners

Rigging pins temporarily hold parts in the exact alignment position specified by the manufacturer so that fasteners can be installed correctly.

Question 22: When a structural repair is made to a pressurized fuselage, special attention must be given to:

Painting the repair the same color as the original skin
Using only AN rivets regardless of original fastener type
Restoring the original pressure-sealing capability using sealant (Correct answer)
Increasing rivet spacing to reduce stress concentration

Correct answer: Restoring the original pressure-sealing capability using sealant

Pressurized fuselage repairs must restore the original airtight seal using approved sealant to maintain cabin pressurization and structural integrity.

Question 23: An aircraft's aluminum skin shows signs of fine, worm-like lines of corrosion products beneath the paint film, particularly in a high-humidity environment. Which type of corrosion is most likely present?

Pitting
Stress corrosion cracking
Intergranular corrosion
Filiform corrosion (Correct answer)

Correct answer: Filiform corrosion

Filiform corrosion is characterized by its worm-like appearance as it forms tunnels of corrosion products under the paint. It is common on painted aluminum surfaces that are exposed to high humidity.

Question 24: During a sheet metal repair, when must a doubler be used in addition to the filler patch?

Only when the original skin thickness is less than 0.032 inches
Whenever the damaged area exceeds the allowable limits for a simple filler patch (Correct answer)
When more than three rivets in a row must be replaced
On all repairs to pressurized fuselage skin regardless of damage size

Correct answer: Whenever the damaged area exceeds the allowable limits for a simple filler patch

A doubler is required when damage exceeds the limits for a simple filler patch, providing the additional material needed to restore original structural strength.

Question 25: What does 'grain direction' mean when working with aircraft sheet metal?

The preferred direction of paint application
The direction the metal crystals were aligned during rolling (Correct answer)
The orientation of corrosion protection coating application
The direction of surface scratches from milling

Correct answer: The direction the metal crystals were aligned during rolling

Grain direction refers to the alignment of metal crystals caused by the rolling process, affecting strength and bend characteristics.

Question 26: Which statement about deburring rivet holes in sheet metal is correct?

Deburring is only required on holes larger than 3/16 inch diameter
Deburring removes material and therefore weakens the sheet around the hole
All rivet holes must be deburred to remove sharp edges that could initiate cracks (Correct answer)
Deburring is optional on interior structure not subject to fatigue loads

Correct answer: All rivet holes must be deburred to remove sharp edges that could initiate cracks

All rivet holes must be deburred because sharp edges and burrs concentrate stress and can initiate fatigue cracks.

Question 27: When is a logbook entry for an inspection considered complete per 14 CFR Part 43.11?

When the mechanic verbally notifies the owner
When the date, aircraft total time, and mechanic signature/certificate number are recorded (Correct answer)
When the FAA Form 8130-3 is filed
When a squawk sheet is attached to the airframe log

Correct answer: When the date, aircraft total time, and mechanic signature/certificate number are recorded

Part 43.11 requires the entry to include the date, aircraft total time in service, and the signature and certificate number of the approving mechanic.

Question 28: What documentation must a technician complete after performing a flight control rigging inspection and adjustment?

A logbook entry is only required if the aircraft is returned to service after annual inspection
Only an entry in the aircraft logbook if hardware was replaced
A maintenance record entry in the aircraft records per 14 CFR 43.9 describing the work, date, and signature (Correct answer)
A Form 337 filed with the FAA within 48 hours

Correct answer: A maintenance record entry in the aircraft records per 14 CFR 43.9 describing the work, date, and signature

14 CFR 43.9 requires a maintenance record entry for all maintenance, preventive maintenance, rebuilding, or alteration, including rigging adjustments, with date, description, and approval signature.

Question 29: In a damage-tolerant aircraft structure, what is the purpose of fracture mechanics-based inspection intervals?

To ensure cracks are detected and repaired before reaching critical size (Correct answer)
To identify structures that need immediate replacement
To eliminate cracks before they can form
To certify that no fatigue damage exists in the fleet

Correct answer: To ensure cracks are detected and repaired before reaching critical size

Fracture mechanics sets inspection intervals so that any crack growing from the assumed initial flaw size will be found and repaired before it reaches the critical size that causes failure.

Question 30: What is the primary function of a static inverter in an aircraft electrical system?

To convert AC power to DC power for battery charging.
To regulate the voltage output of the main generators.
To convert DC power from the aircraft battery or DC bus to AC power. (Correct answer)
To provide a stable source of DC power for emergency lighting.

Correct answer: To convert DC power from the aircraft battery or DC bus to AC power.

A static inverter is a solid-state electronic device that converts direct current (DC) into alternating current (AC). This allows DC power from sources like the aircraft's batteries or transformer-rectifier units to be used for instruments and avionics that require AC power, often as a primary or emergency backup source.

Question 31: Which material property describes a metal's ability to be drawn into wire without breaking?

Brittleness
Elasticity
Malleability
Ductility (Correct answer)

Correct answer: Ductility

Ductility is the ability of a material to deform plastically under tensile stress, allowing it to be drawn into wire.

Question 32: What does the 'AD' in the rivet identification code AN470AD4-5 signify?

The material is 2117-T aluminum alloy. (Correct answer)
The rivet requires refrigeration.
The material is 5056 aluminum alloy.
The head style is countersunk.

Correct answer: The material is 2117-T aluminum alloy.

In the standard rivet identification system, the letter code following the head style indicates the rivet's material composition. 'AD' specifies that the rivet is made from 2117-T aluminum alloy.

Question 33: What type of ice protection does the engine air inlet of most large turbofan engines rely upon?

Electrothermal heating mats bonded to the inlet lip
Pneumatic expansion boots on the inlet lip
Hot bleed air from an engine stage ducted through the inlet lip (Correct answer)
Chemical fluid sprayed from a nozzle inside the nacelle

Correct answer: Hot bleed air from an engine stage ducted through the inlet lip

Turbofan engine inlets use hot bleed air ducted through the inlet lip structure to prevent ice formation and protect engine internals.

Question 34: An aircraft's rudder control has more than the specified free play. After checking the rudder pedals and cables, the wear is found at the rudder horn attachment. What is the correct repair?

Replace the worn bolt, bushing, or fitting to restore the specified clearance per the Maintenance Manual (Correct answer)
Apply a corrosion-resistant grease to reduce movement
Install a larger diameter bolt to fill the worn hole
Rerig the cables to take up the slack

Correct answer: Replace the worn bolt, bushing, or fitting to restore the specified clearance per the Maintenance Manual

Worn attachment hardware (bolts, bushings, or fittings) must be replaced with serviceable parts of the correct specification—oversized fasteners without engineering approval are not permitted.

Question 35: On a helicopter, tracking the main rotor blades is done to ensure:

All blades rotate in the same plane of rotation (Correct answer)
Blade chord angles are identical
Blade droop stops are properly adjusted
Blade weights are within limits

Correct answer: All blades rotate in the same plane of rotation

Rotor tracking verifies that all blades rotate in the same plane to minimize vibration caused by out-of-track blades.

Question 36: A mechanic finds corrosion on a steel tubular fuselage truss. After removing the corrosion, the affected tube wall thickness is reduced by 15%. What should be done?

Polish the area smooth and re-measure at 25-hour intervals
Refinish and return to service since corrosion is removed
Apply epoxy primer and monitor at the next inspection
Consult the manufacturer's structural repair manual; likely replacement or reinforcement is needed (Correct answer)

Correct answer: Consult the manufacturer's structural repair manual; likely replacement or reinforcement is needed

Wall thickness reduction of 15% on a structural tube likely exceeds acceptable limits and requires engineering data or SRM guidance before return to service.

Question 37: Which of the following conditions is a primary cause of 'thermal runaway' in an aircraft's nickel-cadmium (Ni-Cad) battery?

High charging current combined with high battery temperature. (Correct answer)
Excessive discharge rates during engine start.
Operation in extremely low ambient temperatures.
Low electrolyte level causing increased internal resistance.

Correct answer: High charging current combined with high battery temperature.

Thermal runaway in a Ni-Cad battery is a dangerous condition where high charging currents and high internal battery temperatures create a self-sustaining cycle. As the battery's temperature increases, its internal resistance drops, causing it to accept even more current from the charging system. This further increases the temperature, leading to an uncontrollable, rapid rise that can destroy the battery and create a fire hazard.

Question 38: A maintenance technician is troubleshooting a pneumatic de-icing boot system that is not inflating properly. The system's engine-driven air pump is verified to be operating correctly. Which of the following components should be inspected next for a possible malfunction?

The oil-to-fuel heat exchanger.
The distributor valve or solenoid. (Correct answer)
The hydraulic reservoir fluid level.
The system's pressure relief valve.

Correct answer: The distributor valve or solenoid.

In a pneumatic de-icing system, the distributor valve (often operated by a solenoid) is responsible for directing the flow of pressurized air to the de-icing boots in the correct sequence. A malfunction in this valve would prevent the boots from inflating, even if the air pump is working correctly.

Question 39: Which document defines the minimum inspection requirements for a 100-hour inspection on a certificated aircraft?

The aircraft's weight and balance report
14 CFR Part 43, Appendix D (Correct answer)
14 CFR Part 91.409
AC 43.13-1B

Correct answer: 14 CFR Part 43, Appendix D

14 CFR Part 43, Appendix D lists the scope and detail of items to be included in annual and 100-hour inspections.

Question 40: What is the primary purpose of a fuel boost pump in an aircraft fuel system?

To provide positive fuel pressure and prevent vapor lock (Correct answer)
To measure fuel quantity in the tank
To transfer fuel between wing tanks
To filter contaminants from the fuel

Correct answer: To provide positive fuel pressure and prevent vapor lock

Fuel boost pumps supply positive pressure to the engine-driven fuel pump inlet, preventing vapor lock and ensuring reliable fuel flow especially at high altitudes.

Question 41: A 'pilot hole' in sheet metal work is:

A hole in the fuselage skin used for avionics wire routing
The first rivet hole in a row used to align subsequent holes
A small-diameter starter hole drilled before final-size drilling (Correct answer)
A hole drilled at an angle to guide subsequent straight drilling

Correct answer: A small-diameter starter hole drilled before final-size drilling

A pilot hole is a small-diameter hole drilled first to guide the final-size drill and improve hole location accuracy.

Question 42: What is 'chem-milling' used for in aircraft sheet metal fabrication?

Selectively removing material from sheet metal using chemical etching to reduce weight (Correct answer)
Chemically treating rivets before installation
Cleaning metal surfaces before welding
Applying corrosion-inhibiting primer to bare metal

Correct answer: Selectively removing material from sheet metal using chemical etching to reduce weight

Chem-milling uses controlled chemical etching to precisely remove material from selected areas to reduce weight while maintaining structural integrity.

Question 43: In a brushed DC generator, what is the combined function of the commutator and brushes?

To cool the armature windings by providing an air gap.
To vary the magnetic field strength of the stator.
To provide a sliding electrical connection and convert the internal AC to external DC. (Correct answer)
To regulate the generator's output voltage.

Correct answer: To provide a sliding electrical connection and convert the internal AC to external DC.

As the armature rotates, it generates AC internally. The commutator, consisting of segmented copper bars, rotates with the armature. The stationary carbon brushes ride on the commutator, acting as a mechanical rectifier to reverse the current direction every half-turn, resulting in a DC output to the external circuit.

Question 44: Which non-destructive testing method uses high-frequency sound waves to detect internal defects in metal?

Eddy current inspection
Dye penetrant inspection
Magnetic particle inspection
Ultrasonic inspection (Correct answer)

Correct answer: Ultrasonic inspection

Ultrasonic inspection uses high-frequency sound waves that reflect off internal discontinuities to detect flaws within materials.

Question 45: What is the function of the check valve in a pneumatic deicing boot system?

To limit maximum inflation pressure to 20 psi
To allow the pilot to manually override automatic sequencing
To prevent backflow of air that could collapse an inflated boot prematurely (Correct answer)
To filter moisture from the bleed air supply

Correct answer: To prevent backflow of air that could collapse an inflated boot prematurely

Check valves prevent reverse airflow through the system, ensuring each boot section holds pressure during its inflation cycle.

Question 46: Which repair method is used when the damage to an aircraft skin panel is too extensive for a patch but the surrounding structure is still sound?

Scab patch repair
Insert repair
Flush patch repair
Section replacement (Correct answer)

Correct answer: Section replacement

Section replacement removes the entire damaged section and replaces it with new material when damage is too extensive for patching.

Question 47: Which of the following describes the minimum allowable edge distance for a single row of protruding head rivets in a sheet metal repair?

Three times the rivet shank diameter
Two times the rivet shank diameter (Correct answer)
One and a half times the rivet shank diameter
One times the rivet shank diameter

Correct answer: Two times the rivet shank diameter

According to FAA guidelines (AC 43.13-1B), the minimum edge distance, measured from the center of the rivet hole to the edge of the sheet, should not be less than two times the diameter of the rivet shank for a single row of rivets. This ensures sufficient material strength to prevent the rivet from tearing out the edge of the sheet.

Question 48: Which regulation requires aircraft operators to comply with Airworthiness Directives?

14 CFR 39.7 (Correct answer)
14 CFR 91.403
14 CFR 65.81
14 CFR 43.13

Correct answer: 14 CFR 39.7

14 CFR 39.7 states that no person may operate a product to which an Airworthiness Directive applies except in accordance with the requirements of that AD.

Question 49: During horizontal tail assembly, the stabilizer incidence angle is found to be 0.5° more than specified. What is the most appropriate corrective action?

Adjust the stabilizer attach bolts to shim the leading edge up or down as needed (Correct answer)
File a maintenance record and leave the incidence as found
Replace the horizontal stabilizer
Adjust the elevator trim tab to compensate

Correct answer: Adjust the stabilizer attach bolts to shim the leading edge up or down as needed

Small incidence errors are corrected by adding or removing shims at the stabilizer attachment points to achieve the manufacturer's specified angle.

Question 50: How often must fuel strainers and filters be inspected and cleaned according to FAA regulations?

At each 100-hour or annual inspection and per manufacturer's maintenance schedule (Correct answer)
Once per year during the annual inspection only
Every 500 hours regardless of manufacturer guidance
Only when a fuel system malfunction is detected

Correct answer: At each 100-hour or annual inspection and per manufacturer's maintenance schedule

Fuel strainers and filters must be inspected and cleaned at each 100-hour or annual inspection, and at any additional intervals specified by the aircraft manufacturer's maintenance manual.

Question 51: When forming a bend in sheet metal, the bend allowance refers to:

The setback subtracted from the flat pattern
The springback angle after bending
The arc length of material consumed in the curved portion of the bend (Correct answer)
The extra material added for overlap at the bend

Correct answer: The arc length of material consumed in the curved portion of the bend

Bend allowance is the arc length of material that forms the curved section of the bend, used to calculate flat pattern dimensions.

Question 52: A 'stop-drill' is used in sheet metal repair to:

Create holes for new rivets
Remove old rivets from damaged panels
Halt crack propagation by removing the stress concentration at the crack tip (Correct answer)
Align repair patches during installation

Correct answer: Halt crack propagation by removing the stress concentration at the crack tip

Stop-drilling places a hole at the end of a crack to redistribute stress and prevent the crack from continuing to grow.

Question 53: An aircraft's hydraulic system includes a component that stores fluid under pressure to dampen pressure surges, supplement the system pump during peak demand, and provide an emergency source of hydraulic power. What is this component called?

A shuttle valve
A pressure regulator
A sequence valve
An accumulator (Correct answer)

Correct answer: An accumulator

An accumulator is a steel sphere or cylinder divided into two chambers, one for hydraulic fluid and the other for compressed air or nitrogen. Its primary functions are to store hydraulic fluid under pressure, dampen pressure fluctuations, assist the pump during high demand, and provide emergency hydraulic power.

Question 54: When safety wiring a turnbuckle using the double-wrap method, what is the generally accepted rule regarding the number of threads that may be exposed at either end of the barrel?

Exactly four threads for maximum grip.
No more than three threads. (Correct answer)
At least five threads must be visible for inspection.
No more than five threads.

Correct answer: No more than three threads.

To ensure adequate thread engagement and structural integrity, standard aviation practice dictates that no more than three threads of the turnbuckle terminal should be exposed outside the barrel after tensioning and before safetying. This ensures the connection is strong enough to handle its rated load.

Question 55: What does the term 'airworthy' mean as applied during an airframe inspection?

The aircraft conforms to its type design and is in a condition for safe operation (Correct answer)
The aircraft has no write-ups in the maintenance log
The aircraft has passed all required AD compliance items only
The aircraft has a current annual inspection within the past 12 months

Correct answer: The aircraft conforms to its type design and is in a condition for safe operation

Airworthy means the aircraft conforms to its approved type design and is in a condition for safe operation, per 14 CFR Part 3.

Question 56: A control cable shows a broken wire strand on the outside of a bend near a pulley. Per AC 43.13-1B, this cable should be:

Repaired using a splice fitting
Reported to the FAA before further flight
Monitored at each 100-hour inspection
Replaced immediately (Correct answer)

Correct answer: Replaced immediately

AC 43.13-1B requires replacement of any cable with a broken wire at a bend, as this indicates fatigue and the cable's integrity is compromised.

Question 57: During a pre-flight inspection, a pilot notices a frayed, flat, braided copper cable connecting the aircraft's elevator to the horizontal stabilizer. What is the primary purpose of this bonding strap?

To transmit control position data to the flight data recorder.
To dampen high-frequency vibration of the control surface.
To act as a secondary structural attachment for the control surface.
To provide a low-resistance path for static electricity and fault currents. (Correct answer)

Correct answer: To provide a low-resistance path for static electricity and fault currents.

Bonding straps (or jumpers) are used to create electrical continuity between all metallic components of the aircraft. Their primary purpose is to provide a path of least resistance for static electricity buildup and electrical fault currents, preventing arcing, sparks, and interference with radio and navigation equipment.

Question 58: What is the purpose of using a dimpling operation instead of countersinking on thin sheet metal?

Dimpling is required for all flush rivet installations
Thin sheet does not have enough material depth for a full countersink without knife-edge (Correct answer)
Dimpling creates a stronger joint than countersinking
Dimpling is faster than countersinking for production work

Correct answer: Thin sheet does not have enough material depth for a full countersink without knife-edge

On thin sheets, countersinking can leave a knife-edge around the hole, so dimpling displaces material rather than removing it.

Question 59: When riveting near a formed flange or edge, which direction should the bucking bar force be applied relative to the rivet shank?

At a 45° angle to maximize driven head spread
At the angle matching the countersink angle
Perpendicular to the rivet shank
Parallel to the rivet shank (axially) (Correct answer)

Correct answer: Parallel to the rivet shank (axially)

The bucking bar must be held perpendicular to the sheet surface and aligned axially with the rivet shank to form a properly shaped driven head.

Question 60: After a minor repair and repainting of an aileron, what procedure is critical to perform to prevent a potentially catastrophic in-flight failure?

Re-balancing the control surface. (Correct answer)
Applying a corrosion-inhibiting compound.
Checking for correct color matching under UV light.
Measuring the thickness of the new paint layer.

Correct answer: Re-balancing the control surface.

Adding or removing material, such as paint or body filler, can change the weight distribution of a control surface. If the center of gravity shifts aft of the hinge line, it can lead to aerodynamic flutter at high speeds, which is a rapid, uncontrolled oscillation that can destroy the surface and lead to loss of the aircraft. Re-balancing ensures the center of gravity is correctly located relative to the hinge line.

Question 61: Under what conditions may automotive gasoline (mogas) be used in a certificated aircraft?

Always acceptable as an emergency substitute for avgas
Only when the aircraft has an STC specifically approving its use (Correct answer)
Any time it has the same octane rating as the specified avgas
It may be mixed freely with avgas without restriction

Correct answer: Only when the aircraft has an STC specifically approving its use

Automotive gasoline may only be used in certificated aircraft when a Supplemental Type Certificate (STC) has been issued specifically approving mogas for that aircraft and engine combination.

Question 62: When servicing an air/oil oleo shock strut, a mechanic notices that the strut bottoms out on landing but functions normally during taxi. What is the most likely cause of this issue?

Low hydraulic fluid level. (Correct answer)
Excessive air pressure.
Worn-out seals.
Incorrect type of hydraulic fluid.

Correct answer: Low hydraulic fluid level.

If an oleo strut bottoms on landing, it indicates a lack of hydraulic fluid to cushion the initial impact. During taxi, the loads are less severe, so the remaining fluid and air pressure may appear to function correctly. Excessive air pressure would make the strut too stiff, and worn seals would likely cause fluid leaks.

Question 63: What is the primary advantage of using a flush (countersunk) rivet on external aircraft skin?

It is stronger in shear than a protruding head rivet of the same diameter
It reduces aerodynamic drag by maintaining a smooth surface (Correct answer)
It is easier to install in thin sheet materials
It does not require a bucking bar during installation

Correct answer: It reduces aerodynamic drag by maintaining a smooth surface

Flush rivets create a smooth aerodynamic surface by seating the head level with the skin, reducing drag compared to protruding head rivets.

Question 64: What does the term 'dihedral' refer to in aircraft wing design?

The upward angle of the wings relative to the horizontal (Correct answer)
The thickness-to-chord ratio of the airfoil
The taper ratio from root to tip
The sweep angle of the wing leading edge

Correct answer: The upward angle of the wings relative to the horizontal

Dihedral is the upward angle of the wings from the root to the tip when viewed from the front, which improves lateral stability.

Question 65: A technician observes that a hydraulic system is operating sluggishly. The system has been serviced recently, and the fluid level in the reservoir is correct. Which of the following is the most likely cause of the issue?

The system relief valve is stuck open.
The incorrect type of hydraulic fluid was used.
Air has been introduced into the system. (Correct answer)
The ambient temperature is too high.

Correct answer: Air has been introduced into the system.

Air in a hydraulic system is compressible, unlike hydraulic fluid. When air is present, the force applied by the pump will first compress the air before moving the hydraulic fluid, leading to a spongy feel and sluggish operation of actuators.

Question 66: Which of the following is a critical maintenance practice for pneumatic de-icing boots to ensure their longevity and proper function?

Keeping the boots inflated when the aircraft is parked to prevent creasing.
Testing the system exclusively in sub-zero temperatures to simulate real-world conditions.
Applying a thin layer of hydraulic fluid to keep the rubber supple.
Regularly cleaning the boots with soap and water and performing visual inspections. (Correct answer)

Correct answer: Regularly cleaning the boots with soap and water and performing visual inspections.

Proper care for pneumatic de-icing boots includes regular cleaning with approved mild soap and water to remove insects and contaminants that can degrade the rubber. This is followed by a thorough visual inspection for damage such as cracks, cuts, abrasions, or signs of delamination. This routine maintenance is crucial for identifying issues early and extending the service life of the boots.

Question 67: After rigging a rudder control system, the rudder deflects 25° right but only 20° left. What is the most likely cause?

The rudder hinge bolts are too tight on the left side
The rudder stop on the left side is set too close, or the left cable is over-tensioned relative to the right (Correct answer)
The cable on the right side has too many nicks
The vertical fin is misaligned to the fuselage

Correct answer: The rudder stop on the left side is set too close, or the left cable is over-tensioned relative to the right

Asymmetric deflection typically results from an incorrectly set travel stop on the low-travel side or unequal cable tension causing the neutral position to be offset.

Question 68: A technician is performing a flush patch repair on a pressurized fuselage skin. How should the thickness of the doubler and the filler (patch) relate to the original skin thickness?

The doubler and filler should both be one gauge thicker than the original skin.
The doubler should be the same thickness, and the filler should be one gauge thinner than the original skin.
The doubler should be one gauge thicker, and the filler should be the same thickness as the original skin. (Correct answer)
The doubler and filler should both be the same thickness as the original skin.

Correct answer: The doubler should be one gauge thicker, and the filler should be the same thickness as the original skin.

For a flush patch repair, the filler plug must be of the same gauge and material as the original skin to maintain a smooth surface. The doubler, which provides the structural reinforcement from the inside, should be made of material one gauge heavier (thicker) than the original skin.

Question 69: Which type of aluminum alloy is most commonly used in aircraft skin due to its high strength-to-weight ratio?

3003 series
5052 series
1100 series
2024-T3 (Correct answer)

Correct answer: 2024-T3

2024-T3 aluminum alloy is the most widely used aircraft skin material because of its excellent strength-to-weight ratio and fatigue resistance.

Question 70: An aircraft's electrical system is protected by 'trip-free' circuit breakers. What is the defining characteristic of this type of circuit breaker?

It automatically resets itself once the circuit has cooled down after an overload.
It requires a special tool to be reset, preventing unauthorized reactivation of the circuit.
It will open the circuit to protect against overloads, even if the operating mechanism is held in the 'ON' position. (Correct answer)
It can be manually reset only after the fault condition has been cleared.

Correct answer: It will open the circuit to protect against overloads, even if the operating mechanism is held in the 'ON' position.

A 'trip-free' circuit breaker is a safety device designed to open and interrupt the current flow during an overload condition, regardless of the position of the operating handle. Even if a pilot or maintenance person tries to hold it in the closed ('ON') position, the internal mechanism will remain open as long as the fault exists, preventing damage to the circuit and reducing fire risk.

Question 71: A mechanic is inspecting a main wing spar made of aluminum alloy for suspected subsurface cracks originating from a fastener hole. Which NDT method is most effective for this specific task?

Dye Penetrant Inspection
Eddy Current Inspection (Correct answer)
Visual Tap Test
Magnetic Particle Inspection

Correct answer: Eddy Current Inspection

Eddy current inspection is highly effective at detecting surface and near-surface flaws in conductive materials, like aluminum. It is particularly well-suited for finding cracks around fastener holes. Magnetic particle is for ferrous metals, dye penetrant only finds surface-breaking cracks, and tap testing is for composite delamination.

Question 72: On a light aircraft with a conventional landing gear, how is 'toe-in' on the main gear defined?

The leading edges of the main wheels point slightly inward toward the aircraft centerline when viewed from above (Correct answer)
The wheels point outward from the fuselage centerline when viewed from above
The top of the wheels tilt inward toward the fuselage when viewed from the front
The wheels are canted so the bottoms are farther apart than the tops

Correct answer: The leading edges of the main wheels point slightly inward toward the aircraft centerline when viewed from above

Toe-in means the front of each main wheel points slightly toward the aircraft centerline, reducing side-slip tendency during the ground roll.

Question 73: When assembling a large transport category aircraft's empennage to the fuselage, the horizontal stabilizer incidence is set by:

Shimming or adjusting the rear spar attach point per maintenance manual data (Correct answer)
Adjusting the pitch trim jackscrew range
Shimming the leading edge attach fittings
Bending the stabilizer spar caps

Correct answer: Shimming or adjusting the rear spar attach point per maintenance manual data

Horizontal stabilizer incidence is set by shimming or adjusting the rear spar (or leading edge) attach points per the manufacturer's maintenance manual tolerances.

Question 74: What is the purpose of the 'hold-down' (suction) function in a pneumatic deicing boot system?

To hold accumulated ice in place until the pilot selects a shed cycle
To keep the boot deflated and conformed to the leading edge when not inflating (Correct answer)
To create aerodynamic suction that pulls ice toward the boot for collection
To increase system pressure during the inflation stroke

Correct answer: To keep the boot deflated and conformed to the leading edge when not inflating

Suction is applied to the boot between inflation cycles to hold it tightly against the leading edge skin, minimizing aerodynamic drag and preventing flutter.

Question 75: What is the primary purpose of a trim tab on a control surface?

To increase control surface deflection range
To relieve the pilot of sustained control forces (Correct answer)
To provide aerodynamic balance for the surface
To limit maximum control surface travel

Correct answer: To relieve the pilot of sustained control forces

Trim tabs are adjusted to relieve the pilot of continuous pressure needed to maintain a desired flight attitude.

Question 76: In a pneumatic system, what is the primary purpose of a moisture separator or chemical dryer component?

To remove water vapor and prevent corrosion or freezing. (Correct answer)
To add lubrication to the compressed air.
To increase the pressure of the system.
To cool the compressed air before it enters the system.

Correct answer: To remove water vapor and prevent corrosion or freezing.

As ambient air is compressed, its temperature rises, and it can hold more moisture. When the air cools, this moisture condenses. A moisture separator and/or chemical dryer (desiccant) is installed downstream of the compressor to remove this water vapor, preventing it from causing corrosion or freezing in the pneumatic lines and components.

Question 77: In the context of an aircraft sheet metal repair, what is the primary function of a joggle?

To create a decorative finish on the repair patch.
To provide a space for electrical wiring to pass through.
To allow one sheet of metal to overlap another while maintaining a flush surface. (Correct answer)
To increase the thickness of the material for added strength.

Correct answer: To allow one sheet of metal to overlap another while maintaining a flush surface.

A joggle is an offset bend formed in a piece of sheet metal. Its purpose is to allow a mating part, such as a repair patch or another skin panel, to overlap it without creating a step. This maintains the aerodynamic smoothness of the aircraft's surface by creating a flush joint.

Question 78: A swaged cable terminal is rejected during inspection because it fails the 'slip test.' What does this mean?

The swage die left visible marks on the terminal
The terminal rotated more than 90° under torque
The terminal pulled off or slipped from the cable when proof-loaded (Correct answer)
The terminal did not meet minimum break strength

Correct answer: The terminal pulled off or slipped from the cable when proof-loaded

The slip test proof-loads the swaged terminal to a specified percentage of cable breaking strength; failure means the terminal slipped off or the cable pulled through.

Question 79: An aircraft elevator is rigged with excessive up travel. The most likely result during flight is:

Reduced elevator authority in turbulence
Risk of exceeding limit load factor in pitch-up maneuvers (Correct answer)
Difficulty achieving climb attitude
Increased pitch stability

Correct answer: Risk of exceeding limit load factor in pitch-up maneuvers

Excessive up elevator travel allows the pilot to generate more than the design limit load factor in pitch, potentially causing structural damage.

Question 80: A technician is rigging the flight controls of an aircraft and notes that for a left roll command, the left aileron moves 20 degrees up, while the right aileron moves 15 degrees down. What is this design feature called and what is its primary purpose?

Differential aileron travel; to counteract adverse yaw. (Correct answer)
Aileron droop; to increase lift during takeoff.
Flaperon mixing; to combine the function of flaps and ailerons.
Symmetrical travel; to ensure a constant roll rate.

Correct answer: Differential aileron travel; to counteract adverse yaw.

This is called differential aileron travel. The downward-deflected aileron creates more lift and, as a byproduct, more drag than the upward-deflected aileron. This drag imbalance can cause the aircraft's nose to yaw in the opposite direction of the turn (adverse yaw). By having the up-going aileron travel a greater distance, its drag is increased, helping to equalize the drag on both wings and create a more coordinated turn.

Question 81: What type of fuel system is used on most high-wing general aviation aircraft with gravity-fed carburetor engines?

Centrifugal pump system driven by the accessory gearbox
Pressure injection system with electric pumps
Bladder-cell system pressurized by engine bleed air
Gravity-feed system relying on fuel head pressure from the tanks (Correct answer)

Correct answer: Gravity-feed system relying on fuel head pressure from the tanks

High-wing aircraft with carbureted engines often use a gravity-feed system where fuel flows by gravity from the wing tanks above the engine without requiring a pump.

Question 82: What regulation governs fuel system airworthiness design requirements for certificated aircraft?

14 CFR Part 65 — Certification of Airmen
14 CFR Part 43 — Maintenance, Preventive Maintenance, Rebuilding, and Alteration
14 CFR Part 23 or Part 25, depending on aircraft category (Correct answer)
14 CFR Part 91 — General Operating and Flight Rules

Correct answer: 14 CFR Part 23 or Part 25, depending on aircraft category

Fuel system design and certification standards are contained in 14 CFR Part 23 for normal/utility/aerobatic/commuter aircraft and Part 25 for transport category aircraft.

Question 83: When using a torque wrench on an aircraft fastener, the torque value specified in the maintenance manual refers to:

The total torque including any friction losses in the fitting
The torque applied after reaching initial resistance
The torque with a calibrated impact wrench only
The dry torque value unless otherwise specified (Correct answer)

Correct answer: The dry torque value unless otherwise specified

Torque values in maintenance manuals are dry torque values unless the manual specifically states that lubrication is to be applied.

Question 84: What fuel selector valve position is recommended during takeoff and landing on most aircraft with multiple fuel tanks?

Off
Both tanks or the fullest tank (Correct answer)
Left tank only
Right tank only

Correct answer: Both tanks or the fullest tank

Selecting 'Both' or the fullest tank during takeoff and landing ensures maximum fuel availability and minimizes the risk of fuel starvation during these critical flight phases.

Question 85: During a TKS weeping wing system inspection, the mechanic notices some porous titanium panel holes are clogged. What is the correct maintenance action?

Drill out the clogged holes to restore flow
Apply solvent to dissolve mineral deposits, then reinstall
Replace the clogged porous panel per the AMM (Correct answer)
Flush the system with water at high pressure to clear blockages

Correct answer: Replace the clogged porous panel per the AMM

Clogged TKS panels must be replaced rather than drilled or otherwise modified, as pore size and distribution are precisely controlled for correct fluid flow.

Question 86: Which FAR part establishes the certification standards for ice protection systems on transport category aircraft?

FAR Part 25 (Correct answer)
FAR Part 27
FAR Part 91
FAR Part 23

Correct answer: FAR Part 25

FAR Part 25 covers airworthiness standards for transport category airplanes, including ice protection requirements.

Question 87: A mechanic is about to perform maintenance on a pressurized aircraft fuel line. What is the FIRST step before opening any fittings?

Tag out the fuel pump circuit breaker
Don rubber gloves and safety glasses
Place absorbent material under the work area
Ensure the fuel system pressure is relieved (Correct answer)

Correct answer: Ensure the fuel system pressure is relieved

Before opening any pressurized fuel line fitting, the system pressure must be fully relieved to prevent fuel spray and potential fire or injury.

Question 88: What material is commonly used for flexible fuel hose connections in certified aircraft fuel systems?

Unlined steel braided hose
Aluminum rigid tubing
Copper tubing
Teflon-lined synthetic rubber hose (Correct answer)

Correct answer: Teflon-lined synthetic rubber hose

Teflon-lined synthetic rubber hoses are used for flexible fuel connections because Teflon resists aviation fuel degradation and the rubber provides flexibility to absorb vibration.

Question 89: When fabricating a 90-degree bend in a piece of aluminum sheet metal with a radius of 0.125 inches and a thickness of 0.063 inches, what is the setback?

0.188 inches (Correct answer)
0.251 inches
0.063 inches
0.125 inches

Correct answer: 0.188 inches

For a 90-degree bend, the setback is calculated by adding the bend radius to the thickness of the material. In this case, Setback = Radius + Thickness = 0.125" + 0.063" = 0.188". Setback is a critical calculation for determining the starting point of the bend.

Question 90: Which rivet material is required when repairing magnesium alloy aircraft structure to prevent galvanic corrosion?

2117-T4 aluminum rivets
Stainless steel rivets
Magnesium or aluminum 5056 alloy rivets (Correct answer)
Monel rivets

Correct answer: Magnesium or aluminum 5056 alloy rivets

5056 aluminum rivets must be used with magnesium structure because they are galvanically compatible; other aluminum or steel rivets cause severe galvanic corrosion.

Question 91: What fuel tank venting requirement must be met to prevent structural damage to the tank?

Vents must allow airflow in one direction only
Vent openings must be protected against ice blockage (Correct answer)
All vents must incorporate check valves
Vents must be located only on the top surface of fuel tanks

Correct answer: Vent openings must be protected against ice blockage

FAA regulations require fuel tank vents to be protected against icing so tanks can breathe freely, preventing dangerous pressure differentials that could damage the tank structure.

Question 92: A bellcrank in a flight control system is used primarily to:

Reduce friction in push-pull tube systems
Increase cable tension automatically
Change the direction of control cable or rod movement (Correct answer)
Serve as a cable anchor point at the wing root

Correct answer: Change the direction of control cable or rod movement

A bellcrank converts or redirects the motion of cables or rods, allowing control forces to be transmitted around corners or change direction within the airframe.

Question 93: A mechanic is checking aileron differential rigging on a light aircraft. 'Differential' means:

Both ailerons deflect the same number of degrees in opposite directions
The left aileron travels farther than the right aileron regardless of input direction
The upward-deflecting aileron travels farther than the downward-deflecting aileron to counteract adverse yaw (Correct answer)
The ailerons deflect more at low speed and less at high speed automatically

Correct answer: The upward-deflecting aileron travels farther than the downward-deflecting aileron to counteract adverse yaw

Aileron differential means the up-going aileron deflects more than the down-going aileron, reducing the increased drag on the rising wing and minimizing adverse yaw.

Question 94: In a multi-spar wing, what is the primary function of the front spar compared to the rear spar?

Both spars carry identical loads simultaneously
The front spar carries torsion; the rear spar carries bending
The front spar is structural; the rear spar is purely aerodynamic
The front spar carries most bending loads; the rear spar supports control surfaces and fuel (Correct answer)

Correct answer: The front spar carries most bending loads; the rear spar supports control surfaces and fuel

In most designs the front spar carries the majority of bending and shear from lift, while the rear spar provides attachment for trailing-edge control surfaces and closes the torsion box.

Question 95: What type of fuel is used in most modern turbine-powered aircraft operating in the United States?

Jet-A (Correct answer)
Aviation gasoline (avgas) 100LL
Mogas
JP-4

Correct answer: Jet-A

Jet-A is the standard turbine fuel used in commercial and general aviation jet aircraft in the US due to its consistent flash point and energy content.

Question 96: According to 14 CFR Part 43, Appendix A, which of the following is considered a major alteration to an aircraft's hydraulic system?

Changes to the basic design of the hydraulic system. (Correct answer)
Servicing a hydraulic accumulator with nitrogen.
Replacing a hydraulic hose with an identical, approved part.
Replacing the seals in a brake master cylinder.

Correct answer: Changes to the basic design of the hydraulic system.

14 CFR Part 43, Appendix A defines major alterations. Changes to the basic design of the fuel, oil, cooling, heating, cabin pressurization, electrical, hydraulic, de-icing, or exhaust systems are specifically listed as major alterations. Simple component replacements or servicing are generally considered maintenance or minor repairs.

Question 97: What tool is used to measure the tension of an aircraft control cable?

Torque wrench
Cable tensiometer (Correct answer)
Micrometer caliper
Cable tension gauge pliers

Correct answer: Cable tensiometer

A cable tensiometer (such as a T-5 or C-8 type) is the standard tool used to measure control cable tension.

Question 98: When checking flight control surface travel with a protractor, where is the protractor typically placed?

On the control column or stick
On the adjacent fixed structure
On the spar of the control surface
On the top surface of the control surface at the specified reference location (Correct answer)

Correct answer: On the top surface of the control surface at the specified reference location

The protractor (or inclinometer) is placed on the top surface of the control surface at the reference station specified in the maintenance manual.

Question 99: A technician is troubleshooting a multi-engine aircraft's DC generation system where one generator is not sharing the load equally with the others. Which component is primarily responsible for ensuring all generators connected to a common bus share the electrical load proportionally?

The Generator Control Unit (GCU) (Correct answer)
The reverse current cutout relay
The battery bus
The static inverter

Correct answer: The Generator Control Unit (GCU)

The Generator Control Unit (GCU) is responsible for multiple functions, including voltage regulation and load sharing in multi-generator systems. It senses the load on each generator and adjusts the field excitation to ensure each generator carries its proportional share of the total electrical load, a process often referred to as paralleling.

Question 100: Which type of cable rigging check verifies that control surfaces move in the correct direction when cockpit controls are deflected?

Travel check
Continuity check
Tension check
Operational check (Correct answer)

Correct answer: Operational check

An operational check confirms correct direction of surface movement relative to cockpit control input, ensuring no crossed cables.

FAA Airframe Mechanic Written Exam

Certifies individuals to inspect, maintain, and repair aircraft airframes, ensuring structural integrity and system functionality in accordance with FAA regulations.

100

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120 min

Time Limit

70%

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