AMT Aviation Maintenance Technician Exam — Questions and Answers

Question 1: An aircraft reciprocating engine exhibits low oil pressure at idle but normal pressure at cruise RPM. The MOST likely cause is:

A clogged oil filter bypassing unfiltered oil
Worn engine bearings causing excessive oil clearance (Correct answer)
Low oil temperature causing excessive viscosity
A stuck-closed oil pressure relief valve

Correct answer: Worn engine bearings causing excessive oil clearance

Worn main or rod bearings increase oil clearance, allowing oil to leak past at low pump output (idle), while higher pump output at cruise maintains adequate pressure.

Question 2: Multiple-disc brakes used on transport category aircraft offer which primary advantage over single-disc designs?

Ability to operate without any hydraulic pressure using mechanical linkage
Simpler inspection and maintenance procedures requiring fewer tools
Greater braking force from more friction surface area within a compact, lighter assembly (Correct answer)
Elimination of heat dissipation requirements due to distributed load

Correct answer: Greater braking force from more friction surface area within a compact, lighter assembly

Multiple-disc brakes stack alternating rotating and stationary discs to provide a large total friction area within a compact, weight-efficient package suitable for heavy aircraft with limited wheel well space.

Question 3: When is it acceptable to repair a kinked aircraft hydraulic tube by straightening it?

Whenever the kink does not reduce the internal diameter by more than 20%
If the kink is located more than 6 inches from a fitting
Only if the tubing is stainless steel, not aluminum
Never; kinked tubing must be replaced because the kink work-hardens the material and creates a fatigue crack site (Correct answer)

Correct answer: Never; kinked tubing must be replaced because the kink work-hardens the material and creates a fatigue crack site

Straightening a kinked tube does not restore the original grain structure; the deformed area remains a stress concentration prone to fatigue failure and must be replaced.

Question 4: Why is it important to monitor exhaust gas temperature (EGT)?

To optimize fuel/air mixture (Correct answer)
To ensure propeller balance
To track oil degradation
To lubricate the crankshaft

Correct answer: To optimize fuel/air mixture

Exhaust Gas Temperature (EGT) is a crucial indicator for monitoring the combustion process within an engine. By observing EGT, pilots and mechanics can fine-tune the fuel/air mixture to achieve optimal engine performance, fuel efficiency, and prevent potential damage. An incorrect mixture can lead to issues like pre-ignition, detonation, or excessive cylinder head temperatures.

Question 5: What document must an AMT complete and sign to return an aircraft to service after a 100-hour inspection?

Aircraft maintenance record entry signed under 14 CFR 43.11 (Correct answer)
FAA Form 8110-3
AC Form 8050-1
Maintenance Release (FAA Form 337)

Correct answer: Aircraft maintenance record entry signed under 14 CFR 43.11

14 CFR 43.11 requires the inspector to make a signed logbook entry with the date, aircraft hours, type of inspection, and a statement that the aircraft is airworthy or describing discrepancies.

Question 6: Which part of the CFR covers the certification of aviation maintenance technician schools?

14 CFR Part 43
14 CFR Part 21
14 CFR Part 65
14 CFR Part 147 (Correct answer)

Correct answer: 14 CFR Part 147

14 CFR Part 147 establishes the requirements for certification and operation of Aviation Maintenance Technician Schools (AMTS).

Question 7: Which rivet material is typically used to join magnesium alloy aircraft structures?

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

Correct answer: 5056 aluminum alloy

5056 aluminum alloy rivets are used with magnesium structures because their galvanic potential is closest to magnesium, minimizing corrosion.

Question 8: A technician uses dye-penetrant inspection on a non-magnetic titanium fitting. After applying developer, indications appear as bright red lines. What do these lines represent?

Surface-open discontinuities (cracks or seams) where penetrant has bled back out (Correct answer)
Normal grain boundaries in the metal
Porosity in the casting
Contamination from cleaning solvent

Correct answer: Surface-open discontinuities (cracks or seams) where penetrant has bled back out

In color-contrast dye penetrant inspection, red indications on the white developer background mark locations where penetrant trapped in surface-open defects has been drawn back out.

Question 9: During an engine inspection, what should be checked to assess cylinder condition?

Oil temperature
Ignition timing
Fuel pressure
Cylinder compression (Correct answer)

Correct answer: Cylinder compression

Cylinder compression testing directly measures the sealing integrity of the cylinder, piston rings, and valves. Low compression indicates wear or damage that can significantly impact engine power and efficiency. Therefore, it is a critical assessment during an engine inspection to determine the overall health of the engine's combustion chambers.

Question 10: Which of the following best describes the function of a sacrificial anode?

A noble metal coating applied over a base metal to prevent oxidation
A less noble metal intentionally coupled to a structure to corrode preferentially and protect the structure (Correct answer)
A dielectric barrier placed between two dissimilar metals
A chemical inhibitor applied inside fuel tanks to neutralize contaminants

Correct answer: A less noble metal intentionally coupled to a structure to corrode preferentially and protect the structure

A sacrificial anode is a highly active metal (such as zinc or magnesium) attached to a structure; it corrodes preferentially, protecting the more noble structural metal.

Question 11: An aircraft's logbook shows the last annual inspection was signed off 14 months ago. Under 14 CFR Part 91, this aircraft's airworthiness status for VFR day flight is:

Airworthy if the owner signs a statement of continued airworthiness
Not airworthy for operation under Part 91 without a new annual inspection or special flight permit (Correct answer)
Airworthy for another two months under a grace period provision
Airworthy, because annual inspections are only required for IFR operations

Correct answer: Not airworthy for operation under Part 91 without a new annual inspection or special flight permit

14 CFR 91.409(a) requires an annual inspection every 12 calendar months; after 14 months the inspection is overdue and the aircraft is not airworthy for any flight without a new inspection or an FAA special flight permit.

Question 12: Which type of oil system is used on most gas turbine engines to ensure continuous lubrication during unusual flight attitudes?

Open-circuit total-loss lubrication system
Wet-sump gravity-feed system
Semi-dry sump with a standpipe reserve
Dry-sump pressure-feed system with a dedicated oil tank (Correct answer)

Correct answer: Dry-sump pressure-feed system with a dedicated oil tank

Gas turbine engines use a dry-sump system with a dedicated tank and pressure-fed lubrication so oil supply is not affected by aircraft attitude changes.

Question 13: What is the purpose of 'trimming' a turbine engine?

Aligning the engine mounts for minimal vibration transmission
Balancing the turbine blades to reduce vibration
Adjusting the engine to produce the correct thrust at specified conditions (Correct answer)
Reducing turbine inlet temperature to extend component life

Correct answer: Adjusting the engine to produce the correct thrust at specified conditions

Engine trimming is the adjustment of the fuel control unit to ensure the engine produces the correct rated thrust at specified ambient conditions.

Question 14: During a ground run of a gas turbine engine, a technician observes that the engine lights up, but the RPM fails to accelerate to idle, stabilizing at a lower-than-normal speed. The EGT is observed to be rising, but may not have exceeded limits yet. This condition is known as a:

Hung start (Correct answer)
Hot start
False start
Wet start

Correct answer: Hung start

A hung start occurs when the engine ignites but fails to accelerate to a self-sustaining idle speed. This is often caused by insufficient airflow from the starter to assist the compressor, causing the engine to 'hang' at a lower RPM. A hot start involves EGT exceeding limits, a wet start is a failure to ignite, and a false start is when the starter disengages prematurely.

Question 15: When using a micrometer to measure a shaft, the thimble reads 0.275 in and the vernier scale shows 3. What is the actual measurement if the vernier unit is 0.0001 in?

0.2783 in
0.2750 in
0.2730 in
0.2753 in (Correct answer)

Correct answer: 0.2753 in

The vernier digit (3) adds 3 × 0.0001 in = 0.0003 in to the thimble reading: 0.2750 + 0.0003 = 0.2753 in.

Question 16: Who is responsible for ensuring that an aircraft is maintained in an airworthy condition under 14 CFR Part 91?

The certificated mechanic who last performed maintenance
The registered owner or operator of the aircraft (Correct answer)
The repair station that holds the aircraft's maintenance contract
The FAA inspector assigned to the aircraft's registration district

Correct answer: The registered owner or operator of the aircraft

14 CFR 91.403 places the primary responsibility for maintaining an aircraft in an airworthy condition on the registered owner or operator of the aircraft.

Question 17: What type of engine is most commonly found in small general aviation aircraft?

Ramjet engine
Reciprocating engine (Correct answer)
Turboprop engine
Turbofan engine

Correct answer: Reciprocating engine

Reciprocating engines, also known as piston engines, are the most common powerplants in small general aviation aircraft. They are favored for their reliability, relatively lower cost, and efficiency at the altitudes and speeds typically flown by these aircraft. Turboprop and turbofan engines, while powerful, are generally found in larger, faster, or more specialized aircraft.

Question 18: What is the primary advantage of a delta wing configuration over a conventional swept wing at supersonic speeds?

Better low-speed lift characteristics
Greater fuel capacity
Lower wave drag and improved structural efficiency at high speed (Correct answer)
Simpler manufacturing process

Correct answer: Lower wave drag and improved structural efficiency at high speed

Delta wings provide lower wave drag and a stiffer structural box at supersonic speeds, making them aerodynamically and structurally efficient for high-speed flight.

Question 19: The function of the engine's oil temperature regulator (thermostatic bypass valve) is to:

Control oil pressure by varying the pump output
Prevent oil pressure from exceeding design limits
Bypass the oil cooler when oil temperature is below the desired range (Correct answer)
Reduce oil flow to the engine during high-temperature operations

Correct answer: Bypass the oil cooler when oil temperature is below the desired range

The thermostatic bypass valve allows cold oil to bypass the oil cooler so the engine reaches operating temperature faster, then routes oil through the cooler once the desired temperature is reached.

Question 20: Under the FAA's Safety Management System (SMS), what is the primary goal of hazard identification?

To comply with insurance requirements
To proactively find risks before they cause incidents or accidents (Correct answer)
To reduce maintenance costs
To assign blame for past accidents

Correct answer: To proactively find risks before they cause incidents or accidents

SMS hazard identification is a proactive process to find and assess risks in aviation operations before they result in accidents or incidents.

Question 21: In a semi-monocoque fuselage, which members carry the primary bending loads?

Stringers and longerons (Correct answer)
Gussets and brackets
Formers and bulkheads
Skin panels only

Correct answer: Stringers and longerons

Stringers and longerons run longitudinally and carry the primary bending and tension/compression loads in a semi-monocoque structure.

Question 22: An aircraft reciprocating engine has excessive oil consumption with blue smoke in the exhaust. The most likely cause is:

High oil pressure exceeding the bypass valve setting
Blocked oil cooler causing oil to be expelled through the breather
Worn valve guides or piston rings allowing oil to enter the combustion chamber (Correct answer)
Leaking fuel injector nozzles allowing fuel to dilute the oil

Correct answer: Worn valve guides or piston rings allowing oil to enter the combustion chamber

Blue exhaust smoke is characteristic of oil burning in the combustion chamber, most commonly caused by worn valve guides or piston rings allowing oil past the seals.

Question 23: In aircraft structural terminology, what is a 'joggle'?

A method of welding thin sheet metal
A small offset in a structural member allowing parts to overlap flush (Correct answer)
A type of quick-release fastener
A reinforcement at a bulkhead cutout

Correct answer: A small offset in a structural member allowing parts to overlap flush

A joggle is a small step or offset formed into a structural member so that overlapping parts lie flush with each other.

Question 24: What does 'brake horsepower' (BHP) measure in a reciprocating engine?

The actual usable power delivered at the crankshaft (Correct answer)
The theoretical maximum power based on cylinder displacement
The power lost to friction in the engine
The power required to compress the induction charge

Correct answer: The actual usable power delivered at the crankshaft

Brake horsepower is the actual power delivered at the crankshaft, measured by a brake or dynamometer, accounting for internal engine losses.

Question 25: What is the function of a bonding jumper installed between aircraft components?

To carry main bus current between components
To equalize electrical potential between components and prevent static charge buildup or spark hazards (Correct answer)
To provide a path for lightning to exit the airframe
To ground navigation antennas

Correct answer: To equalize electrical potential between components and prevent static charge buildup or spark hazards

Bonding jumpers create low-resistance electrical paths between components to equalize potential, preventing static discharge sparks and reducing RF interference.

Question 26: Which of the following structural components is primarily responsible for giving a wing its aerodynamic shape (airfoil) and transferring loads from the skin to the spars?

Longerons
Bulkheads
Stringers
Ribs (Correct answer)

Correct answer: Ribs

Ribs are the structural components within a wing that are shaped like the airfoil. [8] Their primary functions are to give the wing its required aerodynamic shape, support the skin against buckling, and transmit the aerodynamic loads from the skin and stringers to the main load-carrying members, the spars. [9, 11]

Question 27: Why are magnetos used in aircraft ignition systems?

To regulate cylinder pressure
To provide spark without external power (Correct answer)
To reduce engine vibration
To control fuel mixture

Correct answer: To provide spark without external power

Magnetos are used in aircraft ignition systems because they are self-contained electrical generators that produce high-voltage current for the spark plugs independently of the aircraft's main electrical system. This provides a crucial safety feature, ensuring the engine can continue to operate and generate spark even if the aircraft's battery or generator fails. They are a reliable and redundant ignition source.

Question 28: When inspecting a welded steel tube fuselage, what defect would require the affected tube to be replaced rather than rewelded?

Superficial surface rust on the exterior
A crack that extends more than one-third of the tube's circumference (Correct answer)
Minor paint blistering near a weld
Slightly uneven bead width along a weld seam

Correct answer: A crack that extends more than one-third of the tube's circumference

Cracks exceeding one-third of the tube's circumference compromise structural integrity to a degree that rewelding cannot adequately restore.

Question 29: Under 14 CFR Part 65, a mechanic may not exercise the privileges of their certificate if they know or have reason to know they are:

Under the influence of any drug or alcohol (Correct answer)
Working outside their usual place of employment
Using tools owned by the aircraft owner
Flying as a passenger on the same aircraft

Correct answer: Under the influence of any drug or alcohol

Part 65.19 prohibits certificate holders from exercising their privileges while under the influence of alcohol or any drug that affects their faculties.

Question 30: Which statement about pre-ignition in a reciprocating engine is correct?

Pre-ignition occurs before the spark plug fires and can cause engine damage (Correct answer)
Pre-ignition is harmless and self-correcting
Pre-ignition occurs after normal spark plug firing and increases power
Pre-ignition is caused by a retarded ignition timing setting

Correct answer: Pre-ignition occurs before the spark plug fires and can cause engine damage

Pre-ignition occurs when the fuel-air charge ignites before the spark plug fires, often due to a hot spot, and can cause severe engine damage.

Question 31: Which rivet is recommended when riveting dissimilar metals that cannot be anodized after assembly to prevent galvanic corrosion?

Monel rivet (Correct answer)
AN470 AD rivet (2117-T4 alloy)
AN426 DD rivet (2024-T4 alloy)
AN470 A rivet (1100 alloy)

Correct answer: Monel rivet

Monel rivets are used where galvanic compatibility is critical, particularly when joining stainless steel or other metals that would create severe galvanic couples with aluminum rivets.

Question 32: Which type of aircraft skin joint allows thermal expansion while maintaining structural integrity?

Splice joint
Lap joint
Butt joint
Joggle joint (Correct answer)

Correct answer: Joggle joint

A joggle joint offsets one piece of skin to allow overlap without creating a raised seam, accommodating thermal expansion.

Question 33: When inspecting a control cable for wear, what condition requires immediate cable replacement?

More than three broken wires in one cable lay (Correct answer)
Dirt accumulation on the outer wires
Minor kinking that can be straightened by hand
Slight surface oxidation on outer wires

Correct answer: More than three broken wires in one cable lay

FAA standards require cable replacement when more than three broken wires are found within one cable lay length.

Question 34: Which document must accompany an aircraft engine when it is shipped from a repair station to another repair station for additional work?

The original type certificate
A signed FAA Form 8050-88
FAA Form 8130-3 indicating the maintenance status and work performed (Correct answer)
FAA Form 337 listing all major repairs

Correct answer: FAA Form 8130-3 indicating the maintenance status and work performed

FAA Form 8130-3 is used to document the maintenance or alteration status of an article and must accompany the article when transferred between facilities.

Question 35: Which structural design philosophy assumes a primary structure will crack but defines inspection intervals to ensure the crack is found before it reaches critical length?

Safe-life design
Infinite-life design
Damage tolerance design (Correct answer)
Fail-safe design

Correct answer: Damage tolerance design

Damage tolerance design acknowledges crack growth will occur and sets inspection intervals based on crack propagation rates to find cracks before they become critical.

Question 36: What does a negative dihedral (anhedral) wing configuration primarily provide?

Greater ground clearance for engines
Increased lateral stability
Decreased lateral stability for improved maneuverability (Correct answer)
Reduced induced drag

Correct answer: Decreased lateral stability for improved maneuverability

Anhedral reduces the natural lateral stability (dihedral effect), which is desirable in highly maneuverable or swept-wing high-speed aircraft.

Question 37: What is the function of a turbocharger in an aircraft engine?

Increases fuel flow
Controls propeller RPM
Regulates oil pressure
Compresses intake air for higher efficiency (Correct answer)

Correct answer: Compresses intake air for higher efficiency

A turbocharger in an aircraft engine is designed to compress the intake air before it enters the engine cylinders. This compression increases the density of the air, allowing more oxygen to be mixed with fuel, especially at higher altitudes where atmospheric pressure is lower. The result is increased engine power and efficiency, improving performance and maintaining horsepower at altitude.

Question 38: In the damage tolerance design philosophy, what is the primary goal regarding structural cracks?

Ensure cracks grow slowly enough to be detected before failure (Correct answer)
Prevent any crack formation in the structure
Use only composite materials to avoid cracks
Eliminate all stress concentrations

Correct answer: Ensure cracks grow slowly enough to be detected before failure

Damage tolerance design ensures that if cracks form, they propagate slowly enough to be found during scheduled inspections before causing catastrophic failure.

Question 39: What does the term 'fail-safe' mean as applied to aircraft structural design?

Safety factor of 1.5 is applied to all design loads
All structural members have identical strength to prevent uneven wear
If one load path fails, alternate structure carries the load to prevent catastrophic failure (Correct answer)
The structure will never fail under any load condition

Correct answer: If one load path fails, alternate structure carries the load to prevent catastrophic failure

Fail-safe design ensures that failure of a single structural member does not lead to catastrophic failure because redundant load paths carry the remaining load.

Question 40: What is the purpose of an 'overhaul' as defined in 14 CFR Part 43, Appendix D?

Restoring an item to a like-new condition using FAA-approved data and within new-part tolerances (Correct answer)
Inspecting an item against manufacturer limits without part replacement
Updating an item to the latest approved configuration
Restoring an item to a serviceable condition by cleaning, inspecting, and replacing worn parts

Correct answer: Restoring an item to a like-new condition using FAA-approved data and within new-part tolerances

An overhaul restores a component to new-part tolerances using FAA-approved data, verifying all dimensions are within limits specified for new parts.

Question 41: According to FAA guidance, which corrosion removal method is preferred for high-strength steel (over 180,000 psi) components?

Blasting with steel shot at high pressure
Electrolytic stripping in a plating tank
Chemical etching with strong acid solutions
Mechanical removal using fine abrasives, avoiding hydrogen-embrittlement risk from acid treatments (Correct answer)

Correct answer: Mechanical removal using fine abrasives, avoiding hydrogen-embrittlement risk from acid treatments

High-strength steel is susceptible to hydrogen embrittlement from acid treatments; mechanical removal with fine abrasives is preferred to avoid introducing hydrogen into the metal.

Question 42: When bleeding aircraft brakes, fluid should flow:

In either direction, as air purges equally well from any bleed point
From the brake assembly upward toward the reservoir to purge air bubbles (Correct answer)
From the top of the brake assembly downward through the lines to the reservoir
By pressurizing the reservoir and letting fluid exit at the brake bleeder fitting

Correct answer: From the brake assembly upward toward the reservoir to purge air bubbles

Aircraft brakes are bled from the brake assembly (bottom) upward toward the reservoir so that air bubbles, which are lighter than fluid, naturally rise and are carried out of the system.

Question 43: What is the structural purpose of intercostal members in an aircraft fuselage?

Connect the fuselage skin to the empennage
Act as attach fittings for the main landing gear
Seal pressure bulkheads against cabin pressurization
Provide support between frames to maintain skin rigidity and carry local loads (Correct answer)

Correct answer: Provide support between frames to maintain skin rigidity and carry local loads

Intercostals span between fuselage frames to stabilize the skin, transfer local loads (such as floor beam reactions), and maintain structural continuity.

Question 44: What ratio is used to determine the correct rivet diameter for a sheet metal repair based on the thickness of the thickest sheet being joined?

5 times the sheet thickness
3 times the sheet thickness (Correct answer)
4 times the sheet thickness
2 times the sheet thickness

Correct answer: 3 times the sheet thickness

Rivet diameter should be approximately 3 times the thickness of the thickest sheet being joined.

Question 45: Detonation in a reciprocating engine is best defined as:

Fuel vaporizing inside the fuel lines before reaching the carburetor
Ignition of residual fuel in the exhaust manifold
Explosive, uncontrolled burning of the fuel-air mixture after normal ignition (Correct answer)
Premature ignition of the fuel-air charge before the spark fires

Correct answer: Explosive, uncontrolled burning of the fuel-air mixture after normal ignition

Detonation is the sudden, explosive auto-ignition of the end gas in the cylinder after normal spark ignition, producing damaging pressure spikes.

Question 46: What condition is indicated when a turbine engine's exhaust gas temperature (EGT) is higher than normal at a given power setting?

The engine is operating more efficiently than normal
Fuel flow is lower than normal for that power setting
Excess air is entering the combustion chamber
Possible turbine damage, compressor fouling, or deterioration reducing engine efficiency (Correct answer)

Correct answer: Possible turbine damage, compressor fouling, or deterioration reducing engine efficiency

High EGT at a given power setting suggests reduced engine efficiency from causes such as compressor fouling, turbine damage, or bleed air leaks, requiring investigation.

Question 47: A technician is servicing a large transport category aircraft and needs to identify the type of hydraulic fluid used in the main system. Which of the following is the most reliable method to determine the correct fluid type?

Checking the color of the fluid in the reservoir sight glass.
Consulting the aircraft manufacturer's maintenance manual or the placard on the reservoir. (Correct answer)
Assuming it uses the most common type, Skydrol, because it is a large aircraft.
Sending a sample of the fluid to a laboratory for analysis.

Correct answer: Consulting the aircraft manufacturer's maintenance manual or the placard on the reservoir.

The most accurate and authoritative source for identifying the correct hydraulic fluid is the aircraft manufacturer's maintenance manual or the instruction plate (placard) affixed to the hydraulic reservoir or the unit being serviced. While fluid color can be an indicator (e.g., mineral-based is often red, phosphate ester is purple), it is not a foolproof method due to potential dye variations or contamination. Assumptions should never be made in aviation maintenance.

Question 48: During engine run-up, you observe that manifold pressure rises when the mixture is leaned. This indicates:

The engine is running at peak power
A magneto is malfunctioning
Fuel injectors are partially clogged
The mixture was previously too rich and leaning improved combustion (Correct answer)

Correct answer: The mixture was previously too rich and leaning improved combustion

A rise in manifold pressure when leaning indicates the mixture was excessively rich; leaning improves combustion efficiency, which is reflected as a slight MP increase.

Question 49: For a turbocharged reciprocating engine, what is meant by the term 'critical altitude'?

The altitude at which the turbocharger waste gate is fully open.
The maximum altitude at which a turbocharger can maintain a rated sea-level manifold pressure. (Correct answer)
The highest altitude the aircraft is certified to fly.
The maximum altitude at which the engine can produce 50% of its rated sea-level power.

Correct answer: The maximum altitude at which a turbocharger can maintain a rated sea-level manifold pressure.

Critical altitude is the maximum density altitude at which a turbocharged engine can maintain its rated sea-level manifold pressure. Above this altitude, the turbocharger can no longer compensate for the decreasing air density, and engine power will begin to decrease.

Question 50: An aircraft's empennage provides what primary function?

Generates primary lift
Houses the fuel tanks
Supports the main landing gear
Provides stability and control in pitch and yaw (Correct answer)

Correct answer: Provides stability and control in pitch and yaw

The empennage (tail assembly) provides longitudinal (pitch) and directional (yaw) stability and control through the horizontal and vertical stabilizers.

Question 51: Why is proper torque application important in aircraft maintenance?

To prevent fastener failure and ensure safety (Correct answer)
To reduce part cost
To make removal easier
To improve paint adhesion

Correct answer: To prevent fastener failure and ensure safety

Proper torque application ensures that fasteners are tightened to their specified tension, creating the necessary clamping force to hold parts together securely. Incorrect torque, whether too loose or too tight, can lead to fastener failure, structural damage, and ultimately compromise the aircraft's safety and airworthiness. Adhering to torque specifications is fundamental for maintaining structural integrity.

Question 52: Which rivet is most appropriate for use in areas that are accessible from one side only?

AN470 universal head rivet
AN426 countersunk rivet
Brazier head rivet
Cherry (blind) rivet (Correct answer)

Correct answer: Cherry (blind) rivet

Blind rivets, such as Cherry rivets, are designed to be installed from one side when the back side is inaccessible.

Question 53: What is the purpose of the 'B' nut (AN818) used in fluid-line fittings?

To clamp a flare sleeve against a fitting, creating a leak-free flared-tube connection (Correct answer)
To plug unused fluid ports
To provide a fused breakaway point under overpressure
To secure the fitting body to the bulkhead

Correct answer: To clamp a flare sleeve against a fitting, creating a leak-free flared-tube connection

The AN818 'B' nut threads onto the fitting body and forces the AN819 sleeve and tube flare into the fitting seat, creating a metal-to-metal seal in flared-tube fluid systems.

Question 54: What is the primary structural function of a honeycomb core in a sandwich composite panel?

Carry primary tensile loads
Provide shear rigidity and separate the face sheets (Correct answer)
Act as a moisture barrier
Conduct electrical current for lightning protection

Correct answer: Provide shear rigidity and separate the face sheets

The honeycomb core resists shear forces and maintains separation between the face sheets, greatly increasing panel stiffness with minimal weight.

Question 55: A technician is troubleshooting a reciprocating engine that is consistently backfiring through the induction system during idle. Which of the following is the most likely cause?

An excessively rich idle mixture.
Incorrectly gapped spark plugs.
An excessively lean idle mixture. (Correct answer)
A stuck-open exhaust valve.

Correct answer: An excessively lean idle mixture.

An excessively lean fuel/air mixture burns very slowly. The combustion can linger in the cylinder until the intake valve opens for the next cycle, at which point it ignites the fresh fuel/air charge in the intake manifold, causing a backfire. An overly rich mixture is more likely to cause afterfiring in the exhaust.

Question 56: According to FAA AC 43.13-1B, what is the minimum edge distance for a rivet hole measured from the center of the hole to the edge of the sheet?

2.5 times the rivet diameter
1.5 times the rivet diameter
2 times the rivet diameter (Correct answer)
3 times the rivet diameter

Correct answer: 2 times the rivet diameter

AC 43.13-1B specifies a minimum edge distance of 2D (twice the rivet diameter) from the rivet centerline to the nearest sheet edge.

Question 57: When safety-wiring a group of bolts using the single-wire method, which direction should the wire be routed so the bolt cannot rotate in the loosening direction?

Counterclockwise around each bolt head
Any direction as long as all bolt heads are looped
Directly to the nearest structural attachment point
From the first bolt to the second so tension pulls each bolt in the tightening direction (Correct answer)

Correct answer: From the first bolt to the second so tension pulls each bolt in the tightening direction

Safety wire must be routed so that any tendency for a fastener to loosen will instead put the wire in tension, pulling the fastener toward the tightening direction.

Question 58: A technician notices white powder deposits around a wing skin lap joint on an aluminum aircraft. This most likely indicates:

Lubricant leaking from the spar
Active corrosion (aluminum oxide) between the mating surfaces (Correct answer)
Anti-icing fluid residue
Paint primer seeping through the joint

Correct answer: Active corrosion (aluminum oxide) between the mating surfaces

White powdery deposits (aluminum oxide) forming at lap joints are a classic sign of active corrosion occurring between the faying surfaces.

Question 59: When inspecting a wood propeller, small cracks running parallel to the grain are typically treated by:

Monitoring until cracks exceed 1 inch
Filling with wood putty and varnishing
Applying epoxy filler and refinishing
Rejecting the propeller from service (Correct answer)

Correct answer: Rejecting the propeller from service

Cracks parallel to the grain in a wood propeller are cause for rejection because they can rapidly propagate and lead to structural failure.

Question 60: An AMT is installing a new compass and must verify its accuracy. What is the maximum allowable deviation error for a magnetic compass after compensation?

5° on any heading (Correct answer)
1° on any heading
10° on any heading
3° on cardinal headings only

Correct answer: 5° on any heading

14 CFR Part 23 and AC 43.13 require that residual magnetic compass deviation not exceed 10° on any heading after compensation — but FAA practical test standards and most aircraft specs call for no more than ±10°; however, the common AMT written test answer is 10°.

Question 61: Which wing construction method uses a thick honeycomb sandwich panel as the primary structural element instead of spars and ribs?

Warren spar construction
Full-depth honeycomb sandwich construction (Correct answer)
Multi-spar box beam construction
Stressed-skin integrally stiffened construction

Correct answer: Full-depth honeycomb sandwich construction

Full-depth honeycomb sandwich construction uses honeycomb core bonded between face sheets as the primary structure, eliminating traditional spars and ribs.

Question 62: What unit is commonly used to measure electrical resistance in aircraft circuits?

Ohms (Correct answer)
Amperes
Watts
Volts

Correct answer: Ohms

Ohms are the standard unit of measurement for electrical resistance, quantifying how much a material opposes the flow of electric current. Understanding resistance is fundamental in aircraft circuits to ensure proper component operation, calculate current flow (using Ohm's Law), and prevent overheating or circuit failure. Volts measure potential difference, Watts measure power, and Amperes measure current.

Question 63: In an aircraft oxygen system, what color are high-pressure oxygen cylinders required to be painted?

Blue
Green (Correct answer)
Red
Yellow

Correct answer: Green

Aviation oxygen cylinders are painted green to identify them as containing aviator's breathing oxygen.

Question 64: What is the function of a propeller governor?

To maintain a constant propeller RPM by varying blade pitch (Correct answer)
To control oil flow to the propeller spinner
To prevent overspeeding by cutting fuel to the engine
To limit maximum blade pitch during feathering

Correct answer: To maintain a constant propeller RPM by varying blade pitch

A propeller governor maintains a selected constant RPM by hydraulically adjusting blade pitch to match the load demand on the engine.

Question 65: Which material is most commonly used for turbine engine combustion liner construction due to its high-temperature oxidation resistance?

Nickel-based superalloys or cobalt-based alloys (Correct answer)
Aluminum alloy 2024-T3
Stainless steel 304
Titanium 6Al-4V

Correct answer: Nickel-based superalloys or cobalt-based alloys

Nickel-based and cobalt-based superalloys are used for combustion liners because they retain mechanical properties and resist oxidation at the extreme temperatures in the combustor.

Question 66: Which of the following best describes 'compressor stall' in a gas turbine engine?

Airflow through a compressor stage separates from the blade surfaces, causing flow disruption (Correct answer)
The compressor rotor exceeds its design RPM limit
Fuel flow exceeds the compressor's capacity to atomize it
The compressor inlet guide vanes close completely

Correct answer: Airflow through a compressor stage separates from the blade surfaces, causing flow disruption

Compressor stall occurs when the angle of attack on compressor blades becomes excessive, causing boundary layer separation and disrupted airflow.

Question 67: In a semi-monocoque fuselage, what is the primary function of longitudinal members such as longerons and stringers?

To absorb and transmit bending, tensile, and compressive stresses. (Correct answer)
To transfer shear stresses from the skin to the wing spars.
To act as the main attachment points for the wings and empennage.
To provide the cross-sectional shape of the fuselage.

Correct answer: To absorb and transmit bending, tensile, and compressive stresses.

Longerons and stringers are the primary longitudinal members in a semi-monocoque fuselage. Their main role is to resist bending moments and carry axial loads (tension and compression) along the length of the fuselage. [3, 6] While formers and bulkheads provide shape, the longerons and stringers form the key load-bearing framework that prevents the fuselage from bending under flight loads. [15]

Question 68: Which turbine engine component is most susceptible to thermal fatigue and oxidation?

Accessory gearbox housing
Fan blade leading edges
High-pressure turbine blades (Correct answer)
Compressor inlet guide vanes

Correct answer: High-pressure turbine blades

High-pressure turbine blades operate at the highest temperatures in the engine and are therefore most susceptible to thermal fatigue and oxidation.

Question 69: A 100% visual inspection of a welded aircraft steel tube fuselage should include checking for:

Interior upholstery condition
Cracks, dents, and evidence of overheating in the heat-affected zone (Correct answer)
Antenna mount alignment
Paint color consistency

Correct answer: Cracks, dents, and evidence of overheating in the heat-affected zone

Welded steel tube structures must be inspected for cracks, dents, and heat-affected zone discoloration that may indicate weld failures or structural compromise.

Question 70: During a pre-inspection of a pneumatic system, a technician notices the air bottles show pressure well below the minimum charge. The FIRST maintenance step is to:

Bleed the system completely before recharging
Inspect the system for leaks before recharging (Correct answer)
Charge the bottles and return the aircraft to service
Replace the air bottles as they are likely faulty

Correct answer: Inspect the system for leaks before recharging

Low bottle pressure indicates a possible leak; the system must be inspected to find and correct the leak source before recharging, otherwise the charge will simply escape again.

Question 71: What does the term 'mean aerodynamic chord' (MAC) represent in aircraft weight and balance?

The average chord length of a tapered or swept wing, used as a reference for CG limits expressed as a percentage (Correct answer)
The chord at the wing tip
The chord at the widest point of the fuselage
The chord at the wing root

Correct answer: The average chord length of a tapered or swept wing, used as a reference for CG limits expressed as a percentage

MAC is the chord of an imaginary rectangular wing with the same lift and center-of-pressure characteristics as the actual wing, used to express CG location as a percentage for tapered or swept wings.

Question 72: Which type of corrosion appears as white or gray powdery deposits on aluminum alloy surfaces?

Fretting corrosion
Surface (uniform) corrosion producing aluminum oxide deposits (Correct answer)
Stress corrosion
Intergranular corrosion

Correct answer: Surface (uniform) corrosion producing aluminum oxide deposits

Uniform surface corrosion on aluminum produces aluminum oxide, which appears as a white or gray powdery or chalky deposit on exposed surfaces.

Question 73: What is 'springback' in sheet metal forming, and how is it compensated?

Metal expanding when heated; compensated by cooling slowly
Surface cracking; compensated by annealing before bending
Elastic recovery after bending; compensated by overbending beyond the desired angle (Correct answer)
Thickness increase during bending; compensated by thinning the material first

Correct answer: Elastic recovery after bending; compensated by overbending beyond the desired angle

Springback is the elastic recovery of metal after the bending force is removed; it is compensated by intentionally overbending past the required angle.

Question 74: A technician is performing a 100-hour inspection and finds an Airworthiness Directive (AD) has not been complied with. What is the CORRECT action?

Placard the affected system and notify the owner in writing
File an FAA SDR and allow continued operation
Document the finding and return the aircraft to service pending compliance
Comply with the AD or obtain an FAA-approved exemption before returning the aircraft to service (Correct answer)

Correct answer: Comply with the AD or obtain an FAA-approved exemption before returning the aircraft to service

An uncomplied-with AD is an airworthiness violation; the aircraft cannot legally be returned to service until the AD is accomplished or a valid FAA exemption is obtained.

Question 75: What term describes the gradual reduction in wing thickness and/or chord from root to tip?

Washout
Dihedral
Sweep
Taper (Correct answer)

Correct answer: Taper

Taper refers to the reduction in wing chord and/or thickness from the root to the tip to improve aerodynamic efficiency.

Question 76: A wing rib that does NOT extend the full depth of the wing and is used to maintain airfoil shape between main ribs is called a:

Main rib
False rib (Correct answer)
Drag rib
Compression rib

Correct answer: False rib

A false rib (or nose rib/auxiliary rib) spans only the leading edge area and helps maintain airfoil contour between full-depth ribs.

Question 77: Under 14 CFR Part 65, an Airframe and Powerplant mechanic certificate requires a minimum of how many months of practical experience?

30 months for combined A&P (Correct answer)
6 months each with a certificated mechanic supervisor
12 months each for airframe and powerplant
18 months for combined airframe and powerplant

Correct answer: 30 months for combined A&P

14 CFR 65.77 requires 30 months of practical experience working on both airframes and powerplants to qualify for the combined A&P certificate.

Question 78: What is the function of the fuel control unit (FCU) on a turbine engine?

Boosts fuel pressure from tank pressure to combustion chamber pressure
Filters fuel to remove contaminants before the combustion chamber
Dumps fuel overboard during an engine overspeed condition
Meters fuel flow to the engine based on power lever position, engine speed, and inlet conditions (Correct answer)

Correct answer: Meters fuel flow to the engine based on power lever position, engine speed, and inlet conditions

The FCU schedules and meters fuel delivery to maintain desired engine speed and prevent overtemperature or overspeed across all operating conditions.

Question 79: Which term describes a mandatory correction issued by the FAA for an unsafe condition?

Repair Notice
Maintenance Directive
Airworthiness Directive (Correct answer)
Service Bulletin

Correct answer: Airworthiness Directive

An Airworthiness Directive (AD) is a legally enforceable regulation issued by the FAA to correct an unsafe condition in an aircraft, engine, propeller, or appliance. Compliance with ADs is mandatory for continued airworthiness, ensuring that identified safety issues are addressed promptly and consistently across the fleet. ADs are critical for maintaining the safety of the flying public.

Question 80: What type of weld joint is used when two pieces of metal overlap and are welded along the edge of one piece?

Butt joint
Lap joint (Correct answer)
Tee joint
Corner joint

Correct answer: Lap joint

A lap joint is formed when two pieces overlap and a fillet weld is made along the edge of the top piece where it meets the surface of the bottom piece.

Question 81: An AMT discovers a major repair is needed on an aircraft. Which form must be used to report the repair?

FAA Form 8050-1
FAA Form 8130-3
FAA Form 337 (Correct answer)
FAA Form 8710-1

Correct answer: FAA Form 337

FAA Form 337 (Major Repair and Alteration) must be completed for all major repairs and major alterations to aircraft.

Question 82: Propeller slip is defined as the difference between:

Blade angle at tip and blade angle at root
Geometric pitch and effective pitch (Correct answer)
Takeoff RPM and cruise RPM
Propeller diameter and hub diameter

Correct answer: Geometric pitch and effective pitch

Slip is the difference between geometric pitch (theoretical advance) and effective pitch (actual advance per revolution), representing aerodynamic inefficiency.

Question 83: The "neutral axis" of a structural beam under bending is the location where:

Maximum tensile stress occurs
Maximum compressive stress occurs
Neither tensile nor compressive stress exists (Correct answer)
Maximum shear stress occurs

Correct answer: Neither tensile nor compressive stress exists

The neutral axis is the plane within a beam where bending stress is zero, with tension on one side and compression on the other.

Question 84: A reciprocating engine exhibits low oil pressure accompanied by high oil temperature. What is the most likely cause?

Worn bearings providing excessive clearance, allowing oil to bypass and reducing pressure while increasing friction heat (Correct answer)
Low oil temperature thermostat set too low causing sluggish oil flow
Overfilled oil sump causing oil to be carried through the breather
Blocked oil cooler bypass valve stuck in the open position

Correct answer: Worn bearings providing excessive clearance, allowing oil to bypass and reducing pressure while increasing friction heat

Worn engine bearings increase oil clearances, reducing resistance and pressure while generating additional friction heat, causing the combined low pressure/high temperature symptom.

Question 85: Which aircraft document lists required inspections and maintenance intervals?

Maintenance manual (Correct answer)
Logbook
Registration certificate
Airworthiness certificate

Correct answer: Maintenance manual

The aircraft's maintenance manual is the authoritative document provided by the manufacturer that details all required inspections, maintenance procedures, and their specific intervals. It contains comprehensive instructions for servicing, troubleshooting, and repairing the aircraft. Adhering to these guidelines is essential for maintaining the aircraft's airworthiness and operational safety.

Question 86: When a certificated mechanic performs preventive maintenance on an aircraft under 14 CFR Part 43, who is authorized to perform such maintenance?

Only repair stations certificated under 14 CFR Part 145
The registered owner or operator of the aircraft if they hold at least a private pilot certificate (Correct answer)
Any person trained by an FAA-certificated repair station
Only certificated mechanics with both Airframe and Powerplant ratings

Correct answer: The registered owner or operator of the aircraft if they hold at least a private pilot certificate

14 CFR 43.3(g) allows the registered owner or operator of an aircraft to perform preventive maintenance if they hold at least a private pilot certificate and the aircraft is not used in air carrier service.

Question 87: What is the purpose of the propeller governor's speeder spring?

To provide a mechanical backup in case of hydraulic pressure failure
To set the desired RPM by opposing the flyweight force; the pilot compresses the spring via the prop control to select higher RPM (Correct answer)
To prevent the propeller blades from over-pitching during descent
To dampen vibration transmitted from the engine crankshaft to the propeller hub

Correct answer: To set the desired RPM by opposing the flyweight force; the pilot compresses the spring via the prop control to select higher RPM

The speeder spring in the governor establishes the set-point RPM by opposing the centrifugal flyweights; moving the prop control increases spring tension to allow higher RPM before the flyweights take action.

Question 88: Which type of torque wrench displays the applied torque on a dial or digital readout without requiring the technician to preset a value?

Preset click-type torque wrench
Slip-type torque wrench
Impact torque wrench
Indicating (deflecting beam) torque wrench (Correct answer)

Correct answer: Indicating (deflecting beam) torque wrench

Indicating or deflecting-beam torque wrenches show live torque on a scale or display, allowing the technician to read the value directly as force is applied.

Question 89: A selector valve in a hydraulic system is used to:

Filter particulate contamination from the fluid
Convert mechanical energy into hydraulic pressure
Limit maximum system pressure
Direct fluid flow to the appropriate actuator port to control direction of movement (Correct answer)

Correct answer: Direct fluid flow to the appropriate actuator port to control direction of movement

A selector (directional control) valve routes pressurized fluid to one side of an actuator while connecting the opposite side to return, reversing actuator direction.

Question 90: Which material is most commonly used in modern aircraft skin construction?

Aluminum alloy (Correct answer)
Carbon fiber
Stainless steel
Titanium

Correct answer: Aluminum alloy

Aluminum alloy remains the most commonly used material for modern aircraft skin construction due to its excellent strength-to-weight ratio, corrosion resistance, and relatively low cost. While composite materials like carbon fiber are increasingly used, especially in newer designs, aluminum alloys still form the backbone of the vast majority of aircraft structures. Its workability and repairability are also significant advantages.

Question 91: An aircraft's angle of incidence is defined as the angle between the wing chord line and the:

Relative wind
Vertical axis
Longitudinal axis of the fuselage (Correct answer)
Horizontal datum plane

Correct answer: Longitudinal axis of the fuselage

Angle of incidence is the fixed angle between the wing chord line and the aircraft's longitudinal axis, built into the airframe.

Question 92: Before drilling rivet holes in a repair patch, which layout step is performed first?

Priming all mating surfaces
Trimming the patch to final size after drilling
Countersinking all holes
Marking the rivet centerline and edge distances with a scriber or pencil (Correct answer)

Correct answer: Marking the rivet centerline and edge distances with a scriber or pencil

Rivet centerlines and edge distances must be marked accurately before drilling to ensure proper spacing and edge clearance.

Question 93: Which FAA publication contains the standard practices and procedures approved for use by mechanics when approved data is not specified by a manufacturer?

FAA Order 8900.1
14 CFR Part 145
AC 43.13-1B, Acceptable Methods, Techniques, and Practices — Aircraft Inspection and Repair (Correct answer)
FAA-H-8083-30, Aviation Maintenance Technician Handbook — General

Correct answer: AC 43.13-1B, Acceptable Methods, Techniques, and Practices — Aircraft Inspection and Repair

AC 43.13-1B is the FAA's primary reference for acceptable repair and inspection methods when the manufacturer's maintenance manual does not specify a procedure.

Question 94: 14 CFR 65.83 requires an A&P certificate holder who has not exercised the privileges of their certificate for more than 24 months to:

Retake the FAA written knowledge test
Surrender the certificate and apply for a new one
Satisfactorily complete a refresher course or pass a practical test before resuming certificate privileges (Correct answer)
Obtain a letter of authorization from an FAA FSDO

Correct answer: Satisfactorily complete a refresher course or pass a practical test before resuming certificate privileges

14 CFR 65.83 requires a certificate holder who has not exercised privileges for 24 consecutive months to complete an FAA-approved refresher course or pass a practical test to resume those privileges.

Question 95: What is the maximum zero fuel weight (MZFW)?

The empty weight minus fuel tank weight
The aircraft weight after all fuel is burned in flight
The maximum allowable weight of the aircraft without usable fuel (Correct answer)
The minimum weight at which the aircraft can fly

Correct answer: The maximum allowable weight of the aircraft without usable fuel

Maximum zero fuel weight is the maximum allowable weight of the aircraft and its contents, excluding usable fuel.

Question 96: In an all-metal aircraft structure, what is the primary purpose of a "doubter" (doubler) plate?

Provide attachment points for interior panels
Reduce drag by streamlining panel joints
Seal fuel tank access panels
Reinforce a cutout or repair area by distributing stress (Correct answer)

Correct answer: Reinforce a cutout or repair area by distributing stress

A doubler plate is added over a cutout, repair, or high-stress area to restore original structural strength by distributing load around the discontinuity.

Question 97: What is the purpose of a bleed air system on a turbine-powered aircraft?

To vent excess hydraulic pressure overboard
To provide boundary layer control over wing surfaces
To supply hot compressed air from the engine for cabin pressurization and anti-ice (Correct answer)
To pre-cool engine oil before it enters the oil cooler

Correct answer: To supply hot compressed air from the engine for cabin pressurization and anti-ice

Bleed air is extracted from engine compressor stages and used for cabin pressurization, air conditioning, anti-icing, and pneumatic systems.

Question 98: Why is FOD (Foreign Object Debris) prevention critical in aircraft maintenance?

To track parts inventory
To reduce paperwork
To prevent damage to aircraft and ensure safety (Correct answer)
To speed up workflow

Correct answer: To prevent damage to aircraft and ensure safety

Foreign Object Debris (FOD) prevention is critical because even small objects can cause severe damage to aircraft engines, propellers, and control surfaces, especially during takeoff and landing. This damage can lead to costly repairs, operational delays, and, most importantly, catastrophic safety incidents. Strict FOD control measures are essential to maintain aircraft safety and operational readiness.

Question 99: Which condition would most likely cause a reciprocating engine to run rough at idle but smoothly at higher power settings?

A cracked engine mount
Excessive fuel pressure
A fouled or defective spark plug (Correct answer)
A failed oil pressure relief valve

Correct answer: A fouled or defective spark plug

A fouled spark plug has the greatest effect at low power (idle) because there is less combustion energy to compensate; the engine typically smooths out at higher power.

Question 100: When inspecting a steel control cable for airworthiness, what is the maximum number of broken wires allowed in any one lay length of a 7×19 cable before it must be replaced?

1 broken wire
2 broken wires
3 broken wires (Correct answer)
6 broken wires

Correct answer: 3 broken wires

FAA AC 43.13-1B states that a 7×19 cable must be replaced if 3 or more wires are broken in one lay length.

AMT Aviation Maintenance Technician Exam

The FAA AMT (Aviation Maintenance Technician) Exam certifies aircraft mechanics in airframe systems, powerplant engine maintenance, general maintenance knowledge, and FAA regulations, safety procedures, and documentation.

100

Questions

180 min

Time Limit

70%

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