FAA Aviation Maintenance Technician (AMT) Airframe Knowledge Test — Questions and Answers

Question 1: Which FAR part governs the airworthiness standards for aircraft electrical equipment?

FAR Part 21
FAR Part 23 (Correct answer)
FAR Part 65
FAR Part 91

Correct answer: FAR Part 23

FAR Part 23 establishes airworthiness standards for normal, utility, acrobatic, and commuter category airplanes, including electrical systems.

Question 2: An aircraft owner performs preventive maintenance under 14 CFR 43 Appendix A. Which record entry requirement applies?

The owner must have an A&P cosign the entry
No records are required for owner-performed work
Records are only required if the work exceeds $500 in parts cost
The owner must make an entry in the maintenance record describing the work and certifying it was done properly (Correct answer)

Correct answer: The owner must make an entry in the maintenance record describing the work and certifying it was done properly

14 CFR 43.9 requires all persons who perform maintenance, including owners doing preventive maintenance, to make a signed maintenance record entry.

Question 3: During a borescope inspection of a reciprocating engine cylinder, you observe a gray, sooty deposit on the piston crown. This is MOST indicative of:

Normal combustion byproducts from a slightly rich mixture (Correct answer)
Water contamination in the fuel
Excessive valve guide wear
Detonation damage

Correct answer: Normal combustion byproducts from a slightly rich mixture

Light gray sooty deposits on a piston crown are typical of rich mixture combustion and are generally within acceptable limits.

Question 4: What fluid is specified for most Boeing commercial aircraft hydraulic systems?

Skydrol (phosphate ester) (Correct answer)
Water-glycol
MIL-PRF-83282 (synthetic hydrocarbon)
MIL-PRF-5606 (red mineral oil)

Correct answer: Skydrol (phosphate ester)

Boeing commercial aircraft use Skydrol, a fire-resistant phosphate ester hydraulic fluid, to reduce fire risk in the event of a hydraulic leak.

Question 5: When bonding aircraft components, what maximum resistance is typically allowed between bonded parts?

0.003 ohm
0.05 ohm (Correct answer)
0.001 ohm
1.0 ohm

Correct answer: 0.05 ohm

FAA Advisory Circulars specify that bonding connections should not exceed 0.003 ohm to ensure effective static discharge and EMI shielding.

Question 6: What component prevents back-flow in a hydraulic line when downstream pressure exceeds upstream pressure?

Relief valve
Check valve (Correct answer)
Flow restrictor
Selector valve

Correct answer: Check valve

A check valve allows fluid flow in only one direction and closes automatically when downstream pressure exceeds upstream pressure, preventing back-flow.

Question 7: A reciprocating engine produces a consistent metallic knock that increases with engine load but decreases at higher RPM. This symptom most closely resembles:

Valve float
Crankshaft end-play
Detonation
Connecting rod bearing (big-end) knock (Correct answer)

Correct answer: Connecting rod bearing (big-end) knock

Big-end bearing knock typically increases with load (higher cylinder pressure forces) and can decrease at high RPM as oil centrifugal force improves bearing film.

Question 8: What is the importance of staying current with trends in Material Selection & Properties for Aircraft Maintenance Certification?

Trends do not affect professional practice
It ensures practices remain effective and relevant (Correct answer)
It is not necessary once certified
It is only required for new professionals

Correct answer: It ensures practices remain effective and relevant

Staying current with industry trends ensures that professional practices remain effective, relevant, and aligned with evolving standards.

Question 9: A nose wheel steering system is sluggish in both directions and the hydraulic pressure is normal. What should be investigated?

Cockpit rudder pedal linkage adjustment
Tire inflation pressure
Steering actuator internal wear or restriction in the metering valve (Correct answer)
Main landing gear shimmy damper

Correct answer: Steering actuator internal wear or restriction in the metering valve

Sluggish steering with normal system pressure suggests the actuator has internal wear or the metering/control valve has a restriction reducing flow rate.

Question 10: What does the abbreviation 'BL' represent in aircraft structural location designations?

Baseline — the lowest structural reference point
Butt Line — a lateral measurement from the aircraft centerline (Correct answer)
Body Length — the total fuselage measurement
Brake Line — hydraulic brake system routing

Correct answer: Butt Line — a lateral measurement from the aircraft centerline

BL (Butt Line) is the lateral distance measured left or right from the aircraft's longitudinal centerline, used to locate structural features spanwise.

Question 11: Which of the following is a proper precaution when working around aircraft radar systems?

Use only leather gloves when testing the radar system
Stand directly in front of the antenna during radiation pattern tests
Ensure the radar is in standby or off mode before working within the beam sweep area (Correct answer)
Radar energy is too low to pose a hazard to maintenance personnel

Correct answer: Ensure the radar is in standby or off mode before working within the beam sweep area

Active radar emits high-energy microwave radiation capable of causing internal tissue heating; personnel must remain clear of the antenna sweep and confirm the system is off or in standby.

Question 12: What does a negative arm value indicate in a weight and balance calculation?

The item is located forward of the datum (Correct answer)
The item exceeds the maximum allowable weight
The item is above the aircraft's waterline
The item is located aft of the datum

Correct answer: The item is located forward of the datum

A negative arm value means the item is located forward (ahead) of the datum, producing a negative moment that acts to move the CG forward.

Question 13: A static inverter in an aircraft converts:

High voltage AC to low voltage AC
28V DC to 14V DC
AC to DC
DC to AC (Correct answer)

Correct answer: DC to AC

A static inverter converts DC power from the aircraft bus to AC power needed by instruments and avionics equipment.

Question 14: What is the function of an aircraft VOR receiver?

Provides magnetic bearing to/from a VOR station (Correct answer)
Tracks GPS satellite signals
Measures distance to a ground station
Receives weather data broadcasts

Correct answer: Provides magnetic bearing to/from a VOR station

A VOR receiver measures the phase difference between reference and variable signals to determine the aircraft's magnetic bearing to or from a VOR ground station.

Question 15: What information is typically found on an FAA Form 337?

Pilot training records
Major repair and alteration data including approved methods, materials, and approver information (Correct answer)
Engine run-up test results
Aircraft weight and balance data only

Correct answer: Major repair and alteration data including approved methods, materials, and approver information

FAA Form 337 is the Major Repair and Alteration form, documenting the work performed, method of compliance, and the approving authority.

Question 16: What is the primary advantage of a variable-displacement hydraulic pump over a fixed-displacement pump?

Reduces flow when pressure demand is met, saving power and reducing heat (Correct answer)
Lower initial cost
Simpler internal design
Higher pressure output capability

Correct answer: Reduces flow when pressure demand is met, saving power and reducing heat

Variable-displacement pumps reduce or eliminate output when system pressure is satisfied, saving engine power and reducing heat generation in the hydraulic fluid.

Question 17: What is the typical operating pressure range for a large transport aircraft hydraulic system?

1,500–2,000 psi
8,000–10,000 psi
3,000–5,000 psi (Correct answer)
500–1,000 psi

Correct answer: 3,000–5,000 psi

Large transport aircraft hydraulic systems typically operate between 3,000 and 5,000 psi, with many modern aircraft using 5,000 psi systems for reduced weight.

Question 18: What is the minimum wire bend radius typically specified to prevent conductor damage in aircraft wiring bundles?

1× wire diameter
10× wire diameter
5× wire diameter
3× wire diameter (Correct answer)

Correct answer: 3× wire diameter

AC 43.13-1B specifies that aircraft wire should not be bent to a radius less than 3 times the wire's outside diameter to avoid insulation cracking and conductor fatigue.

Question 19: What does the term 'fatigue strength' refer to in aircraft materials?

Stress level a material can withstand for an infinite number of cycles (Correct answer)
Resistance to surface scratching
Energy absorbed before fracture
Maximum load before permanent deformation

Correct answer: Stress level a material can withstand for an infinite number of cycles

Fatigue strength is the stress level below which a material can endure an indefinitely large number of loading cycles without failing.

Question 20: What is the primary reason titanium alloys are used in aircraft engine compressor blades?

High electrical conductivity
Low cost and easy machinability
Excellent corrosion resistance in fuel systems
High strength-to-weight ratio and heat resistance (Correct answer)

Correct answer: High strength-to-weight ratio and heat resistance

Titanium alloys offer an exceptional strength-to-weight ratio combined with good heat resistance, making them ideal for compressor blades.

Question 21: What does PPE stand for in the context of Aircraft Maintenance Certification safety protocols?

Project Planning Essentials
Professional Performance Evaluation
Public Policy Enforcement
Personal Protective Equipment (Correct answer)

Correct answer: Personal Protective Equipment

PPE stands for Personal Protective Equipment, which includes items worn to minimize exposure to hazards that cause injuries.

Question 22: What is the purpose of a flux gate compass in an aircraft?

Sense fuel quantity
Regulate alternator field current
Detect the Earth's magnetic field for heading reference (Correct answer)
Measure static air pressure

Correct answer: Detect the Earth's magnetic field for heading reference

A flux gate compass uses electromagnetic induction to precisely sense the Earth's magnetic field, providing an accurate heading reference for remote indicating compasses and autopilots.

Question 23: What does a transponder Mode C provide to ATC?

Aircraft position and heading
Ground speed and track
Aircraft identification only
Pressure altitude and identification (Correct answer)

Correct answer: Pressure altitude and identification

Mode C transponders encode and transmit the aircraft's pressure altitude along with its squawk code to ATC radar.

Question 24: What must be included in an aircraft maintenance record after a repair?

Only the name of the airline
Only the aircraft tail number
Only the type of repair performed
Details of the work, completion date, and technician's signature (Correct answer)

Correct answer: Details of the work, completion date, and technician's signature

After any repair or inspection, proper maintenance record-keeping requires that the entry in the aircraft's logbook or maintenance record clearly describes the work performed. This entry must also include the date of completion and the signature and certificate number of the authorized technician. This ensures accountability, traceability, and compliance with aviation regulations, confirming the aircraft's airworthiness.

Question 25: What protection device should be used in an aircraft circuit rather than a fuse when repeated resetting may be required in flight?

Thermal switch
Zener diode
Circuit breaker (Correct answer)
Current limiter

Correct answer: Circuit breaker

Circuit breakers are preferred over fuses in circuits that may need to be reset in flight because they can be manually reset without replacement.

Question 26: An aircraft engine produces rough operation only on the left magneto during the runup magneto check. The MOST likely cause is:

Left magneto impulse coupling worn past limits
Left magneto P-lead is shorted to ground
One or more spark plugs assigned to the left magneto are fouled or failed (Correct answer)
Timing on the right magneto has advanced excessively

Correct answer: One or more spark plugs assigned to the left magneto are fouled or failed

Rough running isolated to one magneto during the drop check most commonly indicates a fouled or failed spark plug on that magneto's circuit.

Question 27: What is benchmarking in the context of Aircraft Maintenance Certification quality management?

Setting minimum acceptable standards
Recording daily activities
Testing equipment functionality
Comparing performance against best practices or competitors (Correct answer)

Correct answer: Comparing performance against best practices or competitors

Benchmarking involves comparing your processes and performance metrics to industry best practices to identify improvement areas.

Question 28: Before working on an aircraft radar system, a technician must ensure the:

Radar is powered on for warm-up
Antenna is pointed skyward
Battery is fully charged
Radar is de-energized and capacitors discharged (Correct answer)

Correct answer: Radar is de-energized and capacitors discharged

Aircraft radar systems store lethal high-voltage charges in capacitors that must be discharged before maintenance to prevent electrocution.

Question 29: When must an IA use a currently effective FAA-approved Airplane Flight Manual (AFM) supplement during an annual inspection?

Only when the aircraft has been involved in an accident
When inspecting aircraft equipped with STCs that require an AFM supplement (Correct answer)
When the aircraft is operated under Part 135
Only when the engine has been overhauled

Correct answer: When inspecting aircraft equipped with STCs that require an AFM supplement

STCs that affect aircraft operating limitations or performance require an AFM supplement, which the IA must verify is present and current during the annual.

Question 30: Why must composite repair patches typically be tapered (scarfed or stepped) rather than having abrupt edges?

To reduce the weight of the repair patch
To distribute load transfer gradually and minimize stress concentrations at patch boundaries (Correct answer)
To allow moisture to escape from the repair area
To comply with visual inspection requirements only

Correct answer: To distribute load transfer gradually and minimize stress concentrations at patch boundaries

Tapered or stepped patch edges distribute the shear load transfer over a length rather than concentrating it at a single discontinuity, preventing edge delamination.

Question 31: When bleeding a hydraulic system, why must air be completely removed?

Air accelerates seal wear only
Air is compressible and causes spongy, unpredictable actuator response (Correct answer)
Air causes fluid to overheat only
Air increases fluid viscosity

Correct answer: Air is compressible and causes spongy, unpredictable actuator response

Air is compressible unlike hydraulic fluid, so trapped air causes spongy, inconsistent actuator movement and can lead to unsafe control responses.

Question 32: During engine teardown, a turbine blade is found with tip rub marks. Per typical maintenance manuals, this blade should be:

Polished smooth and reinstalled
Replaced automatically regardless of depth
Replaced if rub depth exceeds the serviceable limit (Correct answer)
Inspected visually only and approved if no cracks found

Correct answer: Replaced if rub depth exceeds the serviceable limit

Tip rub is evaluated against published serviceable limits; blades within limits may be returned to service, but those exceeding limits must be replaced.

Question 33: What is the standard voltage for most general aviation aircraft DC electrical systems?

24 volts
12 volts
28 volts (Correct answer)
48 volts

Correct answer: 28 volts

Most general aviation aircraft use a 28-volt DC electrical system, which is the FAA and MIL-SPEC standard.

Question 34: What document provides the minimum inspection requirements for an aircraft under a progressive inspection program?

14 CFR Part 91 Appendix D
AC 43.13-1B only
The aircraft's Pilot's Operating Handbook
An FAA-approved inspection program specific to that aircraft (Correct answer)

Correct answer: An FAA-approved inspection program specific to that aircraft

A progressive inspection must follow an FAA-approved program that identifies inspection items, intervals, and procedures for that specific aircraft.

Question 35: What is the correct procedure when mixing different brands of the same type of hydraulic fluid (e.g., Skydrol 500B-4 and Skydrol LD-4)?

Mixing is acceptable if both are phosphate ester type
Drain, flush, and refill — different brands must not be mixed
Check with the aircraft manufacturer's CMM before mixing (Correct answer)
Add a fluid conditioner before mixing

Correct answer: Check with the aircraft manufacturer's CMM before mixing

Even similar-type hydraulic fluids can have additive packages that interact adversely, so the aircraft manufacturer's Component Maintenance Manual must be consulted before mixing brands.

Question 36: On an aircraft structural drawing, what does 'FS 247.5' designate?

Fastener Size 247.5 series
Frame Spacing of 247.5 millimeters
Fuselage Station 247.5 inches from the datum reference point (Correct answer)
Fuel System line 247.5

Correct answer: Fuselage Station 247.5 inches from the datum reference point

FS refers to Fuselage Station, a measurement in inches from the aircraft's forward datum to locate structural positions along the fuselage.

Question 37: Minimum equipment lists (MELs) for air carrier aircraft derive their authority from:

The manufacturer's Flight Crew Operating Manual
The Master Minimum Equipment List (MMEL) approved by the FAA for that aircraft type (Correct answer)
The pilot in command's discretion
14 CFR Part 91 Appendix G

Correct answer: The Master Minimum Equipment List (MMEL) approved by the FAA for that aircraft type

Airline MELs must be based on the FAA-approved MMEL for the specific aircraft type and then approved by the FAA for each operator.

Question 38: What type of wire is required in aircraft electrical systems to prevent fire hazard in fuel tank areas?

PVC-insulated wire
Bare copper wire
Aluminum wire
Teflon-insulated wire (Correct answer)

Correct answer: Teflon-insulated wire

Teflon (PTFE)-insulated wire is required near fuel tanks because it is highly resistant to fuel, heat, and flame.

Question 39: What condition does 'intergranular corrosion' specifically affect in aluminum aircraft structure?

The anodized coating on control surface hinges
The grain boundaries within the metal, weakening it from the inside (Correct answer)
Only ferrous metal fittings attached to aluminum structure
Only the painted outer surface of the skin

Correct answer: The grain boundaries within the metal, weakening it from the inside

Intergranular corrosion attacks along grain boundaries of the alloy, reducing structural strength significantly while often showing minimal surface evidence.

Question 40: Which tool is used to measure the internal diameter of a cylinder bore in an aircraft engine?

Outside micrometer
Telescoping gauge and micrometer (Correct answer)
Vernier caliper only
Dial test indicator

Correct answer: Telescoping gauge and micrometer

A telescoping gauge is inserted into the bore and then measured with an outside micrometer to determine the internal diameter accurately.

Question 41: What does the term 'lockout/tagout' (LOTO) specifically prevent during aircraft maintenance?

Foreign object debris entering engines
Corrosion on control surfaces
Fuel system overpressurization during fueling
Unexpected energization or release of stored energy (Correct answer)

Correct answer: Unexpected energization or release of stored energy

LOTO procedures isolate energy sources—electrical, hydraulic, pneumatic, or mechanical—to prevent accidental startup or energy release while personnel work on equipment.

Question 42: Which type of stainless steel is most commonly used for aircraft exhaust components due to its high-temperature oxidation resistance?

Austenitic stainless steel (Correct answer)
Ferritic stainless steel
Martensitic stainless steel
Precipitation-hardening stainless steel

Correct answer: Austenitic stainless steel

Austenitic stainless steels (300 series) maintain strength and resist oxidation at elevated temperatures, making them suitable for exhaust systems.

Question 43: When working in a confined space on an aircraft, what is the minimum requirement before entry?

Notifying the crew chief verbally
A buddy system only
Wearing a hard hat and gloves
Atmospheric testing for oxygen, flammable, and toxic gases (Correct answer)

Correct answer: Atmospheric testing for oxygen, flammable, and toxic gases

Confined space entry requires atmospheric testing to confirm oxygen levels (19.5–23.5%) and absence of hazardous gases before anyone enters.

Question 44: What is the function of a hydraulic accumulator?

Cool hydraulic fluid
Measure system pressure
Store pressurized fluid and dampen pressure surges (Correct answer)
Filter contaminants from fluid

Correct answer: Store pressurized fluid and dampen pressure surges

A hydraulic accumulator stores pressurized fluid under a pre-charged gas pressure to supplement pump output during peak demands and dampen pressure spikes.

Question 45: An ammeter that reads on the discharge side of zero indicates the aircraft battery is:

Disconnected from the bus
Being charged by the alternator
Discharging to supply the bus (Correct answer)
Fully charged and at rest

Correct answer: Discharging to supply the bus

A negative (discharge) ammeter reading means the battery is supplying current to the bus because the alternator output is insufficient.

Question 46: How is CG location calculated?

CG = Total Weight × Total Arm
CG = Total Moment ÷ Total Weight (Correct answer)
CG = Total Weight ÷ Total Moment
CG = Total Moment × Total Weight

Correct answer: CG = Total Moment ÷ Total Weight

CG location is found by dividing the total moment (sum of all moments) by the total weight, giving the CG in inches from the datum.

Question 47: An aircraft ELT must be tested in accordance with:

FAR 91.207 — within first 5 minutes of each UTC hour, for no more than 3 audio sweeps (Correct answer)
FAR 43.15 — during each annual inspection only
FAR 91.207 — within first 5 minutes of each UTC hour
FAR 91.409 — annually with IFR equipment

Correct answer: FAR 91.207 — within first 5 minutes of each UTC hour, for no more than 3 audio sweeps

FAR 91.207 permits ELT functional testing only within the first 5 minutes of each UTC hour, limited to 3 audible sweeps to avoid false alarm reports.

Question 48: What does 'passivation' of stainless steel components involve?

Immersing in nitric or citric acid solution to remove free iron and enhance the chromium oxide layer (Correct answer)
Applying anodic coating by electrolysis
Heating in an inert atmosphere to create a surface oxide
Coating with zinc-chromate primer

Correct answer: Immersing in nitric or citric acid solution to remove free iron and enhance the chromium oxide layer

Passivation removes surface iron contamination with an acid bath, allowing chromium to form a dense, continuous oxide layer that resists corrosion.

Question 49: In a FAR Part 121 air carrier operation, which document defines the minimum equipment that must be operational for dispatch?

The Master Minimum Equipment List (MMEL) only
The Minimum Equipment List (MEL) (Correct answer)
The Aircraft Flight Manual limitations section
The carrier's General Operations Manual

Correct answer: The Minimum Equipment List (MEL)

The airline's FAA-approved Minimum Equipment List (MEL) defines which inoperative items allow dispatch and the conditions and procedures required.

Question 50: Which component converts AC generator output to DC for aircraft bus use?

Rectifier/TRU (Correct answer)
Voltage regulator
Transformer
Inverter

Correct answer: Rectifier/TRU

A Transformer Rectifier Unit (TRU) steps down AC voltage and converts it to DC for the aircraft's DC bus.

Question 51: Which document authorizes return-to-service after a major repair on a certificated aircraft?

FAA Form 8710-1
FAA Form 8060-4
FAA Form 8130-3
FAA Form 337 (Correct answer)

Correct answer: FAA Form 337

FAA Form 337 (Major Repair and Alteration) must be completed and submitted to the FAA for major repairs on certificated aircraft.

Question 52: What is the purpose of a hydraulic system relief valve?

Separate fluid from air
Control actuator speed
Limit maximum system pressure to protect components (Correct answer)
Reduce flow to actuators

Correct answer: Limit maximum system pressure to protect components

A relief valve opens to return fluid to the reservoir when system pressure exceeds the set maximum, protecting pumps, actuators, and lines from over-pressurization.

Question 53: What is the purpose of a 'LIST OF MATERIALS' or 'BILL OF MATERIALS' (BOM) on an aircraft assembly drawing?

To identify each part number, quantity, material spec, and description of items in the assembly (Correct answer)
To record the cost of each component for procurement purposes
To list all raw materials approved by the FAA for aircraft construction
To document the inspection requirements for each assembly step

Correct answer: To identify each part number, quantity, material spec, and description of items in the assembly

The BOM (Bill of Materials) on an assembly drawing lists every item in the assembly with its part number, quantity required, material specification, and description.

Question 54: A hydraulic pump that delivers a fixed volume of fluid per revolution regardless of system pressure is called:

Variable-displacement pump
Demand pump
Fixed-displacement (constant delivery) pump (Correct answer)
Electric motor pump

Correct answer: Fixed-displacement (constant delivery) pump

A fixed-displacement pump delivers the same volume per revolution regardless of system pressure; excess flow must be relieved or unloaded.

Question 55: When using a hand file on an aircraft aluminum part, the technician should use:

A single-cut mill file for smooth finishing cuts (Correct answer)
A rasp file for precision work
A rotary file at high speed for aluminum
A double-cut file for finishing

Correct answer: A single-cut mill file for smooth finishing cuts

A single-cut mill file produces smooth, fine finishing cuts on aluminum and prevents loading (clogging) that double-cut files can cause on soft metals.

Question 56: Which seal material is NOT compatible with Skydrol hydraulic fluid?

Buna-N (nitrile) rubber (Correct answer)
Teflon (PTFE)
Butyl rubber
Ethylene propylene (EPDM)

Correct answer: Buna-N (nitrile) rubber

Nitrile (Buna-N) seals swell and deteriorate rapidly when exposed to Skydrol phosphate ester fluid and must not be used in these systems.

Question 57: When installing a bonding jumper to an airframe structure, what surface preparation is required?

Remove all paint and anodizing from the contact area (Correct answer)
Apply corrosion-inhibiting compound before bonding
Clean with solvent only, leaving primer intact
Paint the contact surfaces before attaching

Correct answer: Remove all paint and anodizing from the contact area

Bare metal-to-metal contact is required for effective electrical bonding; paint and anodizing must be removed from the mating surfaces.

Question 58: Under 14 CFR Part 91.409, what is the maximum interval between required 100-hour inspections for an aircraft operated for hire?

90 hours
125 hours
110 hours (Correct answer)
100 hours

Correct answer: 110 hours

14 CFR 91.409(b) allows up to 10 hours over the 100-hour interval if necessary to reach a maintenance facility, making the maximum 110 hours.

Question 59: What is a primary function of an Aircraft Maintenance Program (AMP)?

To schedule pilot training intervals
To authorize mechanics to perform inspections
To define the scheduled maintenance tasks and intervals required to maintain airworthiness (Correct answer)
To track aircraft fuel consumption

Correct answer: To define the scheduled maintenance tasks and intervals required to maintain airworthiness

An AMP defines the required scheduled maintenance tasks, intervals, and inspection requirements to ensure continued airworthiness.

Question 60: What is the purpose of an aircraft logbook in maintenance procedures?

To schedule flight routes
To track maintenance history and compliance (Correct answer)
To store aircraft fuel data
To record passenger complaints

Correct answer: To track maintenance history and compliance

An aircraft logbook is a vital legal document that meticulously records all maintenance, repairs, modifications, and inspections performed on an aircraft throughout its operational life. It serves as a comprehensive history, ensuring compliance with airworthiness directives and regulatory standards, and is essential for determining the aircraft's current status and value.

Question 61: Which OSHA standard primarily governs hazard communication (HazCom) and Safety Data Sheets in an aircraft maintenance shop?

29 CFR 1910.119
29 CFR 1910.1200 (Correct answer)
14 CFR 65.81
49 CFR 172.101

Correct answer: 29 CFR 1910.1200

29 CFR 1910.1200 is OSHA's Hazard Communication Standard, requiring SDS availability and employee training on chemical hazards.

Question 62: A technician is installing a new fuel selector valve. After installation, what is the FIRST check to perform?

Perform a full fuel system pressure test
Confirm the valve operates through all positions without binding (Correct answer)
Verify correct safety wiring on all fittings
Check for fuel leaks with the system pressurized

Correct answer: Confirm the valve operates through all positions without binding

Valve freedom of movement must be verified before any pressure is applied to ensure no binding or interference that could prevent proper fuel selection.

Question 63: When reinstalling a turbine engine fuel nozzle, the torque value listed in the manufacturer's manual is considered:

A maximum value only
Advisory and may be adjusted by the mechanic
A minimum value only
A specific value with defined tolerance (Correct answer)

Correct answer: A specific value with defined tolerance

Manufacturer-specified torque values for fuel nozzles are specific values with tolerances that must be followed exactly to ensure proper seating and prevent leaks.

Question 64: What is the purpose of a bootstrap reservoir in an aircraft hydraulic system?

Filter return line fluid
Store emergency fluid supply at low pressure
Separate air from hydraulic fluid
Pressurize the reservoir using system hydraulic pressure (Correct answer)

Correct answer: Pressurize the reservoir using system hydraulic pressure

A bootstrap reservoir uses system hydraulic pressure applied to a piston to pressurize the reservoir, ensuring positive pump inlet pressure at altitude where atmospheric pressure is low.

Question 65: When using a rivet gun on an aircraft skin, the bucking bar should be held:

At a 45-degree angle to the rivet
Firmly and squarely against the rivet shank (Correct answer)
Against the manufactured head of the rivet
Loosely to allow vibration absorption

Correct answer: Firmly and squarely against the rivet shank

The bucking bar must be held firmly and squarely against the rivet shank to form a proper shop head and prevent rivet damage.

Question 66: When replacing an aircraft antenna coaxial cable, what must be verified after installation?

VSWR (Voltage Standing Wave Ratio) (Correct answer)
Connector pin count
Cable temperature rating only
Cable color coding

Correct answer: VSWR (Voltage Standing Wave Ratio)

VSWR must be measured after coaxial cable replacement to verify proper impedance matching and antenna system efficiency.

Question 67: Aircraft pneumatic systems typically use which gas as the working medium?

Nitrogen or filtered, dried air (Correct answer)
Oxygen
Hydrogen
Carbon dioxide

Correct answer: Nitrogen or filtered, dried air

Aircraft pneumatic systems use dry nitrogen or filtered, moisture-free air to prevent corrosion and ice formation in valves and actuators.

Question 68: Which of the following correctly describes a 'buddy system' as used in aviation maintenance safety?

Two mechanics signing off the same logbook entry
Two technicians sharing the same task card to speed up work
A training requirement where a new hire shadows a licensed mechanic for 90 days
One technician monitoring another during hazardous operations such as confined space entry or working at height (Correct answer)

Correct answer: One technician monitoring another during hazardous operations such as confined space entry or working at height

A buddy system pairs a working technician with an observer during high-risk tasks to provide immediate assistance or emergency response if an incident occurs.

Question 69: A technician finds a cracked engine mount on a small GA aircraft during a 100-hour inspection. The engine mount is classified as a:

Principal Structural Element requiring FAA-approved repair data (Correct answer)
Cosmetic deficiency deferrable to the next annual inspection
Minor repair item correctable using AC 43.13 standard practices
Component requiring only a logbook entry before return to service

Correct answer: Principal Structural Element requiring FAA-approved repair data

Engine mounts are Principal Structural Elements (PSEs); any crack requires FAA-approved repair data and cannot be addressed with generic standard practices alone.

Question 70: Which regulatory reference establishes weight and balance requirements for certificated aircraft maintenance?

14 CFR Part 91 only
AC 43.13-1B only
14 CFR Part 65
14 CFR Part 43 and the aircraft's approved Type Certificate Data Sheet (TCDS) (Correct answer)

Correct answer: 14 CFR Part 43 and the aircraft's approved Type Certificate Data Sheet (TCDS)

14 CFR Part 43 governs maintenance requirements, and the aircraft's TCDS contains FAA-approved weight and balance limits and data specific to the aircraft type.

Question 71: A mechanic installs a used serviceable component that has no maintenance records. Under FAA standards, this component:

May be installed if it visually appears undamaged
Can be installed with a logbook note that records are unavailable
Is acceptable under the owner-produced parts rule
Cannot be installed because traceability to an approved source is required (Correct answer)

Correct answer: Cannot be installed because traceability to an approved source is required

FAA regulations require aircraft parts to have traceability to an approved production or maintenance source; parts without records are not considered airworthy.

Question 72: When respirator use is required in an aviation maintenance facility, what must the employer provide before a worker is assigned a respirator?

A hearing test and blood pressure check
A 40-hour respirator training course
A medical evaluation to determine the worker's fitness to wear a respirator (Correct answer)
Written authorization from the FAA Safety Officer

Correct answer: A medical evaluation to determine the worker's fitness to wear a respirator

OSHA 29 CFR 1910.134 requires a physician or other licensed health-care professional (PLHCP) medical evaluation before initial respirator assignment to ensure the worker can safely tolerate the physiological demands.

Question 73: Which document defines the approved avionics equipment for a specific aircraft?

FAR Part 91
Aircraft Equipment List / AFMS (Correct answer)
Pilot Operating Handbook only
AC 43.13-1B

Correct answer: Aircraft Equipment List / AFMS

The Aircraft Equipment List or Approved Flight Manual Supplement (AFMS) documents which avionics are approved for installation on a specific aircraft.

Question 74: What is the primary goal of quality assurance in Aircraft Maintenance Certification?

Completing tasks as quickly as possible
Reducing staff numbers
Finding someone to blame for errors
Ensuring consistent standards and continuous improvement (Correct answer)

Correct answer: Ensuring consistent standards and continuous improvement

Quality assurance focuses on maintaining consistent standards and identifying opportunities for continuous improvement in processes and outcomes.

Question 75: Which type of corrosion is most commonly found on aluminum aircraft structures?

Galvanic corrosion
Uniform corrosion
Intergranular corrosion
Pitting corrosion (Correct answer)

Correct answer: Pitting corrosion

Pitting corrosion is a localized form of corrosion that creates small holes or pits on the surface of a metal, commonly found on aluminum aircraft structures. It is particularly dangerous because it can penetrate deeply into the material, significantly weakening the structure even with minimal visible surface damage, making it a critical concern in aircraft maintenance.

Question 76: Which FAA order provides guidance to aviation safety inspectors on airworthiness certification?

FAA Order 8110.4
FAA Order 8130.2 (Correct answer)
FAA Order 8700.1
FAA Order 8900.1

Correct answer: FAA Order 8130.2

FAA Order 8130.2 (Airworthiness Certification of Aircraft and Related Products) guides inspectors on issuing airworthiness certificates.

Question 77: In Aircraft Maintenance Certification, what is a Key Performance Indicator (KPI)?

A compliance checklist
A financial penalty for poor performance
A mandatory training requirement
A measurable value that demonstrates effectiveness (Correct answer)

Correct answer: A measurable value that demonstrates effectiveness

KPIs are quantifiable measurements that demonstrate how effectively objectives are being achieved.

Question 78: What is intergranular corrosion and which aluminum alloy family is most susceptible?

Stress-induced cracking; 6xxx series
Corrosion along grain boundaries; 2xxx series (Correct answer)
Uniform surface attack; 1xxx series
Surface pitting from chlorides; 7xxx series

Correct answer: Corrosion along grain boundaries; 2xxx series

Intergranular corrosion attacks grain boundaries preferentially; 2xxx series (copper-alloyed) aluminum alloys are particularly susceptible when improperly heat-treated.

Question 79: Before performing maintenance on an aircraft hydraulic system, what is the first action a technician must take?

Bleed the accumulator
Change the hydraulic filter
Depressurize the system and verify zero pressure (Correct answer)
Top off the reservoir

Correct answer: Depressurize the system and verify zero pressure

The system must be fully depressurized and pressure verified at zero before opening any hydraulic line to prevent fluid injection injury or component ejection.

Question 80: How is hydraulic fluid contamination level typically classified in aircraft maintenance?

By NAS 1638 or ISO 4406 cleanliness codes (Correct answer)
By MIL-SPEC gravity rating
By color and viscosity only
By FAR Part 43 fluid specs

Correct answer: By NAS 1638 or ISO 4406 cleanliness codes

NAS 1638 and ISO 4406 cleanliness codes classify hydraulic fluid contamination by counting particle sizes per unit volume using automated particle counters.

Question 81: During an annual inspection, a mechanic discovers a 2-inch crack in the firewall. The CORRECT action is to:

Issue a ferry permit for the aircraft to fly to a certified repair station
Repair per the aircraft manufacturer's structural repair manual before returning to service (Correct answer)
Apply fireproof sealant and re-inspect at the next 100-hour
Stop-drill each end and document in the maintenance record

Correct answer: Repair per the aircraft manufacturer's structural repair manual before returning to service

Firewall damage is a structural and fire-safety issue; repair must be accomplished per the manufacturer's SRM before the aircraft is returned to service.

Question 82: What is the purpose of a Mechanical Interruption Summary (MIS) report?

To track daily maintenance inspections
To record scheduled component removals
To document unscheduled engine shutdowns or diversions (Correct answer)
To authorize overtime maintenance work

Correct answer: To document unscheduled engine shutdowns or diversions

A Mechanical Interruption Summary records unscheduled engine shutdowns, flight diversions, and air turnbacks caused by mechanical issues.

Question 83: What wire gauge system is used for aircraft electrical wire sizing?

SWG (Standard Wire Gauge)
IEC 60228
Metric cross-section (mm²)
AWG (American Wire Gauge) (Correct answer)

Correct answer: AWG (American Wire Gauge)

AWG (American Wire Gauge) is the standard system used for aircraft electrical wire sizing in the United States per FAA guidance.

Question 84: What is the purpose of a hydraulic fuse in an aircraft system?

Regulate pump output pressure
Filter large particles from fluid
Automatically shut off flow when excessive flow rate indicates a leak (Correct answer)
Indicate low fluid level

Correct answer: Automatically shut off flow when excessive flow rate indicates a leak

A hydraulic fuse senses an abnormally high flow rate (indicating a downstream rupture or leak) and closes automatically to isolate the failed section and conserve fluid.

Question 85: Which FAA document defines the airworthiness standards for transport category airplanes?

14 CFR Part 25 (Correct answer)
14 CFR Part 29
14 CFR Part 27
14 CFR Part 23

Correct answer: 14 CFR Part 25

14 CFR Part 25 establishes airworthiness standards specifically for transport category airplanes.

Question 86: When is an Airworthiness Directive (AD) considered complied with?

When the manufacturer issues a service bulletin addressing the same issue
When the mechanic reads and understands the AD
When the aircraft owner signs the aircraft logbook
When the specified corrective action is completed and documented in the maintenance record (Correct answer)

Correct answer: When the specified corrective action is completed and documented in the maintenance record

An AD is complied with only when the required corrective action is fully accomplished and properly recorded in the aircraft maintenance records.

Question 87: What is the correct action if a technician's clothing becomes saturated with Skydrol hydraulic fluid?

Remove contaminated clothing immediately and flush affected skin with water for 15 minutes (Correct answer)
Wipe off excess fluid with a dry rag and apply protective cream
Report it to the supervisor only, as Skydrol is non-toxic
Continue working and remove the clothing at the end of the shift

Correct answer: Remove contaminated clothing immediately and flush affected skin with water for 15 minutes

Skydrol is a skin and eye irritant; contaminated clothing must be removed immediately and skin flushed thoroughly to prevent chemical burns.

Question 88: A dye penetrant inspection kit used in aircraft maintenance must be stored:

In direct sunlight to maintain chemical activity
Near the aircraft to reduce handling time
Away from heat sources and in accordance with the manufacturer's temperature range (Correct answer)
In the same cabinet as flammable solvents for convenience

Correct answer: Away from heat sources and in accordance with the manufacturer's temperature range

Dye penetrant chemicals are temperature-sensitive and may be flammable, so they must be stored within the manufacturer's specified temperature range away from ignition sources.

Question 89: An aircraft maintenance technician must have how many recent experience hours to legally exercise A&P privileges?

500 hours total time
1,000 hours within the past 24 months
At least 1 month of work in the past 24 months on aircraft
At least 6 months of work experience in the past 24 months (Correct answer)

Correct answer: At least 6 months of work experience in the past 24 months

14 CFR 65.83 requires a mechanic to have served at least 6 months in their certificate's area within the preceding 24 months to exercise privileges.

Question 90: An exhaust gas temperature (EGT) exceedance occurs during takeoff. After returning to maintenance, the first required action is:

Perform a full borescope inspection immediately
Perform a ground run to verify EGT is now within limits
Replace all turbine blades automatically
Record the peak EGT and duration, then consult the engine manufacturer's exceedance guide (Correct answer)

Correct answer: Record the peak EGT and duration, then consult the engine manufacturer's exceedance guide

The manufacturer's exceedance guide specifies required actions based on peak temperature and duration; the technician must first document the event before taking any further action.

Question 91: What does 'traceability' mean in the context of aviation parts quality control?

The ability to trace a part's origin, manufacture, and maintenance history through documentation (Correct answer)
Monitoring an aircraft's fuel consumption throughout a flight
The process of matching paint colors to original manufacturer specifications
The ability to track an aircraft's GPS position at all times

Correct answer: The ability to trace a part's origin, manufacture, and maintenance history through documentation

Traceability in aviation QC means complete documentation exists linking a part to its raw material, manufacturing process, and all subsequent maintenance events.

Question 92: Which approach best supports quality outcomes in Troubleshooting & Diagnostics for Aircraft Maintenance Certification?

Avoiding quality checks
Rushing through tasks
Relying solely on intuition
Systematic application of evidence-based methods (Correct answer)

Correct answer: Systematic application of evidence-based methods

Evidence-based methods provide a reliable foundation for achieving consistent, high-quality outcomes.

Question 93: Which pneumatic system component removes moisture from compressed air before it enters the distribution system?

Pressure relief valve
Pressure regulator
Air dryer/moisture separator (Correct answer)
Check valve

Correct answer: Air dryer/moisture separator

An air dryer or moisture separator removes water vapor from compressed air to prevent corrosion, ice formation, and valve freezing in the pneumatic distribution system.

Question 94: What condition does a hydraulic system ground test must verify before return to service after seal replacement?

Accumulator pre-charge pressure only
No external leaks at operating pressure and correct actuator travel (Correct answer)
Filter bypass indicator has not popped
Fluid color returns to original

Correct answer: No external leaks at operating pressure and correct actuator travel

A post-maintenance ground test must confirm no external leaks at full operating pressure and verify that all affected actuators move through their correct range of travel.

Question 95: Before using an abrasive wheel on a bench grinder in the hangar, what inspection is required?

Check only the RPM rating on the wheel
Inspect the power cord for fraying
Visual inspection and ring test (tap test) to detect cracks (Correct answer)
No inspection is needed if the wheel was used the previous day

Correct answer: Visual inspection and ring test (tap test) to detect cracks

A visual inspection combined with a ring (tap) test—a clear ring indicates an intact wheel; a dull thud indicates cracks—must be performed before each use per OSHA 1910.215.

Question 96: What is the primary purpose of a current limiter in an aircraft electrical circuit?

Increase circuit ampacity
Balance multiple bus bars
Regulate voltage output
Protect wiring from overload (Correct answer)

Correct answer: Protect wiring from overload

A current limiter (fusible link) opens the circuit to protect wiring from damage caused by excessive current flow.

Question 97: Which tool is commonly used for root cause analysis in Aircraft Maintenance Certification?

Fishbone (Ishikawa) diagram (Correct answer)
Organizational chart
Profit and loss statement
Gantt chart

Correct answer: Fishbone (Ishikawa) diagram

The fishbone diagram helps identify potential causes of a problem by organizing them into categories, revealing root causes.

Question 98: What is 'MAC' (Mean Aerodynamic Chord) used for in weight and balance?

Determining fuel tank capacity
Calculating total engine thrust output
Measuring propeller blade length
Expressing CG location as a percentage of the wing chord for transport-category aircraft (Correct answer)

Correct answer: Expressing CG location as a percentage of the wing chord for transport-category aircraft

For transport-category aircraft, CG is often expressed as a percentage of MAC, which relates the CG position to the aerodynamic characteristics of the wing.

Question 99: Which of the following best describes confidentiality in Aircraft Maintenance Certification?

Protecting sensitive information from unauthorized disclosure (Correct answer)
Sharing information freely with everyone
Keeping all information secret permanently
Only sharing information verbally

Correct answer: Protecting sensitive information from unauthorized disclosure

Confidentiality involves protecting sensitive information and only sharing it with authorized parties who need it.

Question 100: What causes hydraulic fluid to appear milky or foamy?

Overheating only
Water contamination (Correct answer)
Seal degradation only
Metal particle contamination

Correct answer: Water contamination

Water contamination causes hydraulic fluid to appear milky or foamy due to emulsification, which degrades lubrication and can cause corrosion and ice formation.

FAA Aviation Maintenance Technician (AMT) Airframe Knowledge Test

The FAA AMT Airframe (AMA) knowledge test evaluates candidates on airframe structures, hydraulic and pneumatic systems, electrical and avionics systems, and maintenance inspection and documentation required to earn an FAA Aviation Mechanic certificate with Airframe rating.

100

Questions

120 min

Time Limit

70%

To Pass

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