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| Official exam | Aviation Maintenance Technician Powerplant (AMP) |
| Questions | 100 |
| Time | 2 hours |
| Passing score | 70% |
| Pre-licensing or eligibility | Authorisation required to test: original FAA Form 8610-2 signed by an FAA inspector, an authenticated document from an FAA-certificated aviation maintenance technician school (Part 147), or a military Certificate of Eligibility. An FTN from IACRA is needed to schedule. |
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Checked 11 October 2026 from the official sources below. Rules and fees change, so confirm with PSI before you book.
Hangar is a $49 question bank covering five FAA knowledge tests, not a ground school. Here is how it compares with the test prep candidates usually consider, including where they are the better choice. See the comparison with Gleim Aviation, ASA Prepware, King Schools and others.
The real Aviation Mechanic - Powerplant written test has 100 multiple-choice questions (3 options each), a 2-hour time limit, and requires 70% to pass. Questions are drawn across 13 knowledge areas. These follow the FAA-S-ACS-1 blueprint, and this bank mirrors those areas and their weights.
70 percent. Revise each knowledge area to that level in Revision Mode, then run the full exam simulation in Exam Mode before your test date.
The live test bank is not published. Our questions include the FAA's own published sample questions plus original questions written to the FAA-S-ACS-1 blueprint and grounded in the FAA handbooks (FAA-H-8083-30B, 31B and 32B) and 14 CFR, with the source cited in each explanation.
The full Aviation Mechanic - Powerplant bank contains 577 questions with explanations. The free sample is one full practice exam's worth of questions, with at least 5 in every knowledge area so you can revise each topic: 100 questions in all.
A full A&P certificate requires General, Airframe, and Powerplant written tests (plus oral & practical). One Hangar Prep purchase covers every test on the site, for life.
$49, one time, for lifetime access to every test on the site and everything we add later. No subscription.
Yes. One purchase works on up to 3 of your devices. Your progress is saved on each device.
No. The practice tests run in your browser with no signup. Your score history is saved on your own device.
It is organised into 13 modules that follow the exam's own content areas: Reciprocating Engines, Turbine Engines, Engine Inspection, Engine Instrument Systems, Engine Fire Protection Systems, Engine Electrical Systems, Engine Lubrication Systems, Ignition and Starting Systems, Engine Fuel and Fuel Metering Systems, Reciprocating Engine Induction and Cooling Systems, Turbine Engine Air Systems, Engine Exhaust and Reverser Systems and Propellers. Each module is drilled and scored separately, so you can see exactly which areas are exam-ready and which still need work.
Last updated 6 July 2026. The bank is revised whenever the source material it cites changes, and every question carries the source its explanation is drawn from.
A selection of free questions with answers and explanations. Use the interactive modules above for timed, scored drills.
An alternator's rotating field is supplied through what components?
Why: In a typical alternator the rotating field is energized through slip rings and brushes that carry only the small field current; the higher-current AC output is taken from the stationary stator windings (no commutator). FAA-H-8083-32B ch.4.
The oil pressure pump in a lubrication system is most commonly what type?
Why: The engine oil pressure pump is typically a gear-type positive-displacement pump, which delivers a fixed volume per revolution; the pressure relief valve then limits the maximum pressure. FAA-H-8083-32B ch.6.
A turbonormalized (normalizer) turbocharger system is designed to do what?
Why: A turbonormalizing system is set up to maintain sea-level manifold pressure as the aircraft climbs (recovering the power that would otherwise be lost with altitude), rather than boosting the engine above its normal sea-level rating. FAA-H-8083-32B ch.3.
What is the function of the turbine section of a gas turbine engine?
Why: The turbine section extracts energy from the hot, high-velocity gases leaving the combustor; this drives the compressor, the accessory gearbox, and (on fans/props) the fan or propeller through the shaft. FAA-H-8083-32B ch.1.
The oil cooler flow control (thermostatic) valve routes oil around the cooler when the oil is what?
Why: When the oil is cold, the thermostatic flow control valve bypasses the cooler so the oil warms quickly; as the oil reaches temperature the valve routes it through the cooler to hold the target temperature. FAA-H-8083-32B ch.6.
The two categories of turbine thrust reverser are which?
Why: Thrust reversers are divided into mechanical-blockage (a physical obstruction, e.g., clamshell/cone, placed in the exhaust) and aerodynamic-blockage (cascade vanes and blocker doors that redirect fan air). FAA-H-8083-32B ch.3.
Which of the following may be used to mark turbine engine components exposed to high temperatures?
Why: Layout dye (lightly applied), a felt tip marker, or chalk may be used to mark turbine combustion-section parts exposed to high temperatures; wax/grease and graphite pencils are prohibited per FAA-H-8083-32B ch.10.
What is the primary difference of an 'ashless dispersant' aviation oil?
Why: Ashless dispersant oils contain dispersant additives that keep combustion by-products and contaminants suspended (so they can be filtered/drained) without leaving the metallic ash that detergent additives would. FAA-H-8083-32B ch.6.
Aircraft AC electrical systems commonly operate at what frequency?
Why: Aircraft AC systems typically operate at 400 Hz (rather than 50/60 Hz), which allows smaller, lighter transformers and motors; the constant speed drive keeps the generator frequency at 400 Hz. FAA-H-8083-32B ch.4.
An engine's recommended time between overhaul (TBO) is best described as what?
Why: TBO is the manufacturer's recommended number of operating hours (or calendar time) between overhauls; for most part 91 operations it is advisory, not a mandatory limit, though condition still governs continued airworthiness. FAA-H-8083-32B ch.10.
Compressor bleed air is also used for pneumatic engine starting in what way?
Why: For pneumatic starting, air (from an APU, a ground cart, or a running engine's bleed) drives an air-turbine starter, which spins the compressor up to starting speed. FAA-H-8083-32B ch.1.
When starting a turbine engine, a hung start is indicated if the engine
Why: A hung start is when the engine lights off but fails to accelerate to (reach) idle rpm per FAA-H-8083-32B ch.10.
Straight mineral oil and ashless dispersant oil should be handled how during a break-in to overhaul transition?
Why: The recommended practice is to break the engine in on straight mineral oil so the rings seat, then switch to ashless dispersant oil per the engine manufacturer's guidance once break-in is complete. FAA-H-8083-32B ch.6.
Cylinder head temperature (CHT) and exhaust gas temperature (EGT) are monitored to manage what?
Why: CHT indicates how well the cylinders are being cooled (and warns of overheating), and EGT reflects the mixture; together they let the operator manage cooling airflow and mixture to keep the engine within temperature limits. FAA-H-8083-32B ch.3.
Before adding oil to an engine, the technician must verify what?
Why: The technician must use the correct type (mineral vs ashless dispersant) and grade of oil specified by the engine manufacturer; mixing incompatible types or wrong grades can degrade lubrication. FAA-H-8083-32B ch.6.
The distributor in a magneto system does what?
Why: The magneto distributor routes the high-voltage secondary output to each spark plug in turn, in the engine's firing order, as the engine rotates. FAA-H-8083-32B ch.4.
What is 'valve overlap' in a reciprocating engine?
Why: Valve overlap is the brief interval, near the end of the exhaust stroke and the start of the intake stroke, when both the intake and exhaust valves are open; it improves volumetric efficiency and cooling. FAA-H-8083-32B ch.1.
A magneto continues to fire the engine even if the aircraft's master switch is turned off because it is what?
Why: Because the magneto is self-contained and engine-driven, it keeps producing ignition as long as the engine turns, even with the aircraft master (battery) switch off — which is why a propeller must always be treated as if the ignition is live. FAA-H-8083-32B ch.4.
A carburetor meters fuel in proportion to airflow using what principle?
Why: A carburetor uses a venturi: as air accelerates through the venturi its pressure drops, and this low pressure draws fuel from the discharge nozzle in proportion to the airflow, metering the fuel-air mixture. FAA-H-8083-32B ch.2.
During an engine inspection, flexible hoses (fuel, oil) are checked for what?
Why: Engine flexible hoses are inspected for leaks, cracking, chafing, hardening/deterioration, and security of fittings; hoses have a limited service life and are replaced accordingly. FAA-H-8083-32B ch.8.
Residual magnetism is important to a DC generator because it does what?
Why: A DC generator relies on residual magnetism in the field poles to begin producing a small voltage when it starts turning; this builds up the field and output. Loss of residual magnetism requires flashing the field. FAA-H-8083-32B ch.4.
Which of the following defects is a cause for rejection of wood propellers?
Why: Bonding or separation of the trailing edge is a cause for rejection of wood propellers per FAA-H-8083-32B ch.7.
Cowling on an air-cooled engine is designed to do what with the cooling air?
Why: The cowling (with baffles) ducts incoming air, builds a pressure differential across the engine, forces the air through the cylinder fins for cooling, and directs the heated air out the rear (through cowl-flap or fixed exits). FAA-H-8083-32B ch.3.
A term commonly used when two or more electrical terminals are installed on a single lug of a terminal strip is
Why: Installing two or more terminals on a single lug of a terminal strip is commonly called stacking per FAA electrical references.
A rate-of-rise thermal detector will NOT give a warning in which situation?
Why: A rate-of-rise (thermocouple) detector responds to a rapid temperature rise; a slow, gradual overheat may not trigger it, which is why overheat/continuous-loop systems are also used. FAA-H-8083-32B ch.9.
When carburetor heat is applied and ice is present, the rpm typically does what?
Why: Applying carburetor heat first causes a small rpm drop (warmer, less dense air/richer mixture); if ice was present, the rpm then rises as the melting ice clears the induction passage, confirming the ice. FAA-H-8083-32B ch.3.
What carburetor component limits the maximum airflow into the engine at full throttle?
Why: The venturi limits the maximum airflow into the engine at full throttle per FAA-H-8083-32B ch.2.
During fuel injection nozzle maintenance, blocked or dirty nozzles cause what symptom?
Why: Dirty or partially blocked injection nozzles disturb the even fuel distribution, making some cylinders run lean and others rich; this shows up as rough running and a spread in cylinder EGTs, and the nozzles are cleaned/flow-checked. FAA-H-8083-32B ch.2.
Excessive propeller vibration on a constant-speed installation is commonly checked by first doing what?
Why: When a propeller vibrates, blade tracking and blade angle settings are checked first (blades not tracking or unequal blade angles are common causes) before looking further, such as at balance or engine sources. FAA-H-8083-32B ch.7.
When a wet-sump engine's oil is checked with the dipstick, the reciprocating engine should be checked when?
Why: A reciprocating (wet-sump) engine's oil is checked after it has been inactive long enough for the oil to drain to the sump; a turbine engine is checked shortly after shutdown before the oil drains from the tank. FAA-H-8083-32B ch.6.
A fixed engine fire extinguishing system discharges its agent how?
Why: A fixed (high-rate-discharge) engine fire system stores agent in a pressurized bottle; when the crew fires it, an electrically ignited cartridge (squib) ruptures a disk to release the agent rapidly into the fire zone. FAA-H-8083-32B ch.9.
A turbine engine insulation blanket is typically constructed of what?
Why: Insulation blankets are made of insulating material with a stainless steel outer cover to withstand the high temperatures, reducing radiated heat to surrounding structure. FAA-H-8083-32B ch.6.
AC 43.13-1B may be used as the basis for an engine-related repair when what is true?
Why: AC 43.13-1B provides acceptable methods/techniques usable when no manufacturer-published or other FAA-approved data exists for the specific repair; the repair must still satisfy 14 CFR 43.13(a). FAA-H-8083-32B ch.8.
The firing order of a nine-cylinder single-row radial engine is what?
Why: The firing order of a nine-cylinder radial engine is 1-3-5-7-9-2-4-6-8, arranged so the firing impulses are evenly distributed around the crankcase. FAA-H-8083-32B ch.1.
A turbine engine inlet lip and struts are commonly anti-iced by what means?
Why: Turbine inlets are anti-iced by routing warm bleed air through the inlet lip (and inlet guide vanes/struts); some turboprop inlets instead use electrical heating elements in the lip. FAA-H-8083-32B ch.1.
An auxiliary power unit (APU) can supply which of the following on the ground?
Why: An APU provides electrical power and bleed air on the ground (and sometimes in flight), used for engine starting, air conditioning, and other pneumatic needs. FAA-H-8083-32B ch.1.
How is anti-icing fluid ejected from the slinger ring on a propeller?
Why: Anti-icing fluid is ejected from the slinger ring by centrifugal force per FAA-H-8083-32B ch.7.
A convergent turbine exhaust nozzle affects the gas how?
Why: As gases flow into the convergent exhaust nozzle the passage narrows, forming a convergent duct that increases the gas velocity (converting pressure to velocity) as it leaves the engine. FAA-H-8083-32B ch.3.
A turbine engine hot section is particularly susceptible to which kind of damage?
Why: The turbine engine hot section is particularly susceptible to cracking per FAA-H-8083-32B ch.10.
Turbine engine cases and fan cases include a 'containment' design feature to do what?
Why: Fan and turbine cases are designed (or fitted with containment rings/Kevlar wrap) to contain a released blade within the engine case in the event of a blade failure, preventing it from penetrating the fuselage or wing. FAA-H-8083-32B ch.1.
The green arc on an engine instrument (e.g., oil pressure, tachometer) indicates what?
Why: The green arc indicates the normal operating range of the parameter; yellow is the caution/precautionary range and a red radial line is a limit not to be exceeded. FAA-H-8083-32B ch.10.
On a turboprop, torque is frequently sensed by what means?
Why: Many turboprop torquemeters develop an oil pressure proportional to the torque carried through a helical gear in the reduction gearbox; this pressure is displayed as torque (or as a percent) for power setting. FAA-H-8083-32B ch.10.
The turbine engine exhaust cone (aft of the turbine) does what to the gas as it flows through the diverging passage?
Why: The exhaust cone collects the turbine discharge into a solid flow; because the annular passage diverges rearward, the gas velocity decreases slightly and its pressure increases. FAA-H-8083-32B ch.1.
During a turbine engine air-system inspection, cooling-air ducting and baffle seals are checked for what?
Why: Cooling ducting (rigid/flexible) and baffle seals are inspected for cracks, leaks, security, and deterioration, because any leakage reduces the cooling airflow reaching the components. FAA-H-8083-32B ch.1.
The compressor bleed air used for cabin functions is taken from where?
Why: Bleed air for cabin pressurization, heating, cooling, and anti-ice is tapped from the compressor, where the air is already compressed and hot. FAA-H-8083-32B ch.1.
The propeller angle of attack (AOA) is the angle formed by what?
Why: AOA is the angle between the relative wind (the air striking the blade, a resultant of forward velocity and rotational velocity) and the blade chord — distinct from blade angle, which is measured to the plane of rotation. FAA-H-8083-32B ch.7.
Fixed fire protection systems are mandatory on which engines/installations?
Why: Fixed fire detection/extinguishing systems are mandatory on multiengine turbine-powered aircraft (and other specified installations) because of the fire risk in their engine zones. FAA-H-8083-32B ch.9.
In an underspeed condition, the governor responds how?
Why: In underspeed there is not enough centrifugal force, so the flyweights tilt inward; the speeder spring forces the pilot valve down, metering oil to decrease pitch (lower blade angle), which unloads the engine and raises rpm to on-speed. FAA-H-8083-32B ch.7.
An advantage of FADEC fuel control over a hydromechanical control is what?
Why: FADEC provides more precise, computer-optimized fuel scheduling across all conditions and automatic engine protection, improving efficiency and reducing crew workload compared with a purely hydromechanical control. FAA-H-8083-32B ch.2.
On a four-stroke engine, the camshaft turns at what speed relative to the crankshaft?
Why: Because each cylinder's valves open only once every two crankshaft revolutions, the camshaft is driven at one-half crankshaft speed on a four-stroke engine. FAA-H-8083-32B ch.1.
On EICAS/ECAM, the primary engine parameters (such as N1 and EGT) are normally displayed how?
Why: The primary engine parameters (N1, EGT, N2, etc.) are shown continuously on the EICAS/ECAM primary display because they are the most critical for monitoring; secondary parameters may be on a selectable page. FAA-H-8083-32B ch.10.
After a false (wet) start on a turbine engine (fuel but no light-off), a key action before re-start is to do what?
Why: After a wet/false start (fuel introduced but no ignition), the engine is motored (dry cranked) with the fuel off to clear the accumulated fuel and vapor from the combustor/tailpipe, preventing a hot start or tailpipe fire on the next attempt. FAA-H-8083-32B ch.4.
An engine manufacturer's Instructions for Continued Airworthiness (ICA) airworthiness-limitations section is treated how?
Why: The airworthiness-limitations section of the engine ICA lists mandatory replacement times and required inspections and is mandatory (it may only be changed with FAA approval). FAA-H-8083-32B ch.8.
A thermocouple fire detection system responds to what?
Why: A thermocouple system generates a voltage from a rapid rate of temperature rise (hot vs cold junction); it does not warn on a slow, general overheat, unlike a thermal switch that closes at a set temperature. FAA-H-8083-32B ch.9.
Propeller blade angle is defined as the angle between what?
Why: Blade angle, usually measured in degrees, is the angle between the blade chord (face) and the plane of propeller rotation; it is measured at a reference blade station. FAA-H-8083-32B ch.7.
If fuel is found running from the carburetor with the engine not running, the likely cause is that the
Why: Fuel leaking from the carburetor with the engine not running is most likely caused by the float needle valve not seated properly per FAA-H-8083-32B ch.2.
How does a diesel (compression-ignition) engine ignite its fuel, unlike a gasoline engine?
Why: A diesel engine compresses air to a high ratio, raising its temperature enough that injected fuel ignites spontaneously from the heat of compression; it has no spark plugs, unlike a spark-ignition gasoline engine. FAA-H-8083-32B ch.1.
A turbine fuel control's overspeed/overtemperature protection does what?
Why: The turbine fuel control includes limiters that reduce/cap fuel flow to prevent the engine from exceeding its maximum rpm and turbine temperature limits, protecting the engine even if the pilot demands more. FAA-H-8083-32B ch.2.
The volume of a cylinder equals 70 cubic inches when the piston is at bottom center. When the piston is at the top of the cylinder, the volume equals 10 cubic inches. What is the compression ratio?
Why: Compression ratio = bottom-center volume / top volume = 70/10 = 7:1 per FAA-H-8083-32B ch.1.
Turbine inlet temperature (TIT) is monitored because it reflects what?
Why: TIT (or ITT) measures the gas temperature at/near the turbine inlet, the hottest practical measuring point; it is monitored closely because the turbine operates near its material temperature limit and overtemperature causes rapid damage. FAA-H-8083-32B ch.10.
Igniter plugs used in turbine engines have a long service life because they
Why: Turbine igniter plugs have a long service life because they do not require continuous operation (fire mainly during start) per FAA-H-8083-32B ch.4.
In a typical engine fuel system, the sequence from tank to cylinder is generally what?
Why: Fuel flows from the tank through the boost/engine-driven pump and filter to the metering unit (carburetor, injection system, or turbine fuel control), which delivers the correct fuel-air mixture/flow to the cylinders/combustor. FAA-H-8083-32B ch.2.
During start, a starter-generator draws heavy current from the battery/ground power to do what, then reverses role how?
Why: As a starter, the starter-generator draws heavy current to crank the engine; once the engine is self-sustaining, its circuitry reconfigures it as a generator that supplies the bus and recharges the battery. FAA-H-8083-32B ch.5.
A differential (reverse-current) protection feature in an AC generator system trips the generator when it senses what?
Why: Differential protection compares current entering and leaving the generator; a difference (fault current flowing into the generator) indicates an internal fault and trips the generator off the bus. FAA-H-8083-32B ch.4.
When inspecting an engine oil filter/screen at an oil change, finding metal particles indicates what?
Why: Metal particles found on the oil filter/screen (or magnetic chip detector) during an oil change indicate possible internal wear or component distress; the type/quantity is analyzed and the cause investigated before further operation. FAA-H-8083-32B ch.6.
What does a thrust reverser do, and when is it used?
Why: A thrust reverser deploys to redirect the fan and/or exhaust gas flow forward, producing a rearward-then-forward reaction that helps decelerate the aircraft during the landing roll; it is stowed in normal flight. FAA-H-8083-32B ch.1.
The reason for flashing the field in a generator is to
Why: Flashing the field restores residual magnetism to the generator field frame per FAA-H-8083-30B.
What does an impulse coupling do for starting a reciprocating engine?
Why: An impulse coupling is a spring device on the magneto drive that, at cranking speed, holds and then rapidly releases the magnet to produce a strong spark, while also retarding the timing to prevent kickback during start. FAA-H-8083-32B ch.4.
Before working near a turbine thrust reverser, the technician must do what?
Why: Because the reverser has powerful moving parts, it must be mechanically locked out from deploying while personnel are working in its area; the systems are normally locked stowed until commanded to deploy. FAA-H-8083-32B ch.3.
How does a fuse differ from a circuit breaker?
Why: A fuse has a metal element that melts at excess current and must be replaced; a circuit breaker opens on overcurrent but can be reset to restore the circuit. FAA-H-8083-32B ch.4.
An abnormally high fuel flow at a given power setting can indicate what?
Why: Fuel flow higher than normal for a given power setting can indicate a fuel leak, a fuel-control/metering fault, or engine deterioration; comparing fuel flow to expected values is a useful troubleshooting/monitoring tool. FAA-H-8083-32B ch.10.
An engine that has been submerged (e.g., in a flood or ditching) requires what?
Why: A submerged (flood/immersion) engine requires a special inspection and usually a teardown/overhaul because water and contaminants enter the engine and cause corrosion and bearing/component damage. FAA-H-8083-32B ch.8.
A failed cabin-heat heat exchanger is dangerous chiefly because it can do what?
Why: A crack in the heat-exchanger surface lets exhaust gases escape into the cabin heat air, introducing carbon monoxide into the cabin — a serious poisoning hazard. FAA-H-8083-32B ch.3.
A single-row radial engine always has what number of cylinders, and why?
Why: A single-row radial engine has an odd number of cylinders (3, 5, 7, or 9); the odd count is required so the firing impulses are evenly spaced. Double-row radials (e.g., 14, 18) combine two odd rows. FAA-H-8083-32B ch.1.
A 'Dynafocal' engine mount is designed so the mount attach points do what?
Why: A Dynafocal mount angles the isolator attach points so their axes converge on the engine's center of gravity; this arrangement more effectively isolates engine vibration from the airframe. FAA-H-8083-32B ch.8.
Missing or deteriorated inter-cylinder baffle seals (the rubber strips) cause what?
Why: The rubber inter-cylinder baffle seals close the gaps so cooling air is forced over the fins; if they are missing, hardened, or torn, air leaks through the gaps and some cylinders run hot, so the seals are inspected and replaced. FAA-H-8083-32B ch.3.
A hot-section inspection of a turbine engine focuses on which components?
Why: A hot-section inspection examines the combustion section (liners, fuel nozzles) and turbine section (blades, vanes, discs) for cracks, burning, erosion, warping, and hot spots, since these run at the highest temperatures. FAA-H-8083-32B ch.1.
Magneto-to-engine timing sets what?
Why: Magneto timing establishes the crankshaft position — a specified number of degrees before top dead center — at which the magneto's points open and fire the spark plug, so combustion is properly phased with the piston. FAA-H-8083-32B ch.4.
Turbine engine oils are typically what type?
Why: Turbine engines use synthetic oils formulated to withstand the high operating temperatures and to resist thermal breakdown; they are not interchangeable with reciprocating-engine mineral/AD oils. FAA-H-8083-32B ch.6.
On an engine instrument, a red radial line marks what?
Why: A red radial line marks a limit not to be exceeded (maximum or minimum) — e.g., maximum EGT or oil temperature; the green arc is the normal range and the yellow arc is the caution range. FAA-H-8083-32B ch.10.