FAA Aviation Mechanic Powerplant (AMP) practice questions
335 free questions with answers and explanations.
- 251.A direct-cranking electric starter is engaged to start a reciprocating engine, and the engine successfully starts and runs. What component prevents the starter motor and its gear train from being driven and damaged by the now-running engine?Ignition and Starting Systems
- 252.A turbine engine uses a combined starter-generator unit on the accessory gearbox. How does this component function during a normal engine start and after start?Ignition and Starting Systems
- 253.A twin-engine aircraft experiences a right engine failure in cruise flight. The pilot opens the fuel crossfeed valve. What is the primary function this action performs?Fuel, Induction and Lubrication
- 254.A mechanic examines turbine blades removed from an engine and notes that the airfoil passages between adjacent blades converge, causing gas pressure to drop and velocity to increase as the gas passes through the moving blade itself. This blade design is best classified as a(n)Turbine Engines
- 255.A mechanic inspecting continuous-flow fuel injection nozzles finds heavy carbon deposits partially blocking the nozzle orifices, causing rough idle. What is the most likely cause of this carbon buildup?Engine Inspection
- 256.A gear-driven supercharger has an impeller drive ratio of 8:1. If the engine crankshaft is turning at 2,500 RPM, what is the impeller speed?Fuel, Induction and Lubrication
- 257.A pilot reports that during climb power on a hot day, an engine began running extremely rough with a rapid rise in cylinder head temperature, occurring even before the fuel/air mixture would normally be ignited by the spark plugs. A carbon deposit acting as a glowing hot spot in the combustion chamber is suspected. This condition is best described as:Reciprocating Engines
- 258.A technician studying a valve timing diagram notes that the intake valve closes considerably after bottom dead center (BDC) on the compression stroke rather than exactly at BDC. What is the primary reason for this delayed intake valve closing?Reciprocating Engines
- 259.Unlike a reciprocating engine's dual continuous ignition system, a turbine engine's ignition exciter typically operates on what duty cycle during normal flight operations?Ignition and Starting Systems
- 260.An aircraft is parked at the gate with both engines shut down. Ground crew reports that cabin air conditioning and electrical power are being supplied without a ground cart connected. What onboard component is most likely providing this power?Turbine Engines
- 261.During an inspection, a mechanic notices a hairline crack radiating from one of the attachment screw holes on an aluminum propeller spinner dome. What should the mechanic do?Engine Inspection
- 262.A technician suspects a crack in a magnesium alloy engine crankcase half and wants to perform a nondestructive inspection to confirm it. Which method is appropriate for detecting surface cracks on this nonferrous casting?Engine Inspection
- 263.A student mechanic is asked to define the term 'blade angle' for a fixed-pitch propeller. Which statement correctly describes it?Propellers
- 264.A mechanic is overhauling a carburetor equipped with an automatic mixture control (AMC) unit. What is the primary function of this component?Fuel, Induction and Lubrication
- 265.During a top overhaul, a mechanic inspects the exhaust valve rotators (rotocoils) on a reciprocating engine cylinder and finds that one rotator is not turning the valve during operation. What is the most likely consequence of a non-functioning valve rotator?Engine Inspection
- 266.A vintage aircraft is equipped with a wood propeller. Which construction feature is specifically used to protect the wood laminations from moisture absorption and warping?Propellers
- 267.During a borescope inspection of a turbine engine, a technician notices rub marks with metal transfer on the tips of several turbine blades where they contact the shroud. What is the most appropriate next step?Engine Inspection
- 268.A turbine engine's exhaust gas temperature (EGT) trend monitoring log shows the following at a fixed reference power setting: at engine installation, EGT was 905°C with a redline of 950°C. After 500 hours of operation at the same power setting, EGT has risen to 928°C. What does this trend indicate, and what is the current EGT margin?Engine Inspection
- 269.A technician performs a compressor water wash on a turbine engine that has been operating in a coastal, dusty environment. What is the primary purpose of this maintenance procedure?Turbine Engines
- 270.A technician is inspecting a turbocharged reciprocating engine equipped with an absolute pressure controller (APC) in addition to the standard wastegate actuator. What is the function of the APC?Fuel, Induction and Lubrication
- 271.During a normal turbine engine start, the starter begins rotating the compressor. At approximately what point in the sequence should the fuel and ignition systems typically be energized?Turbine Engines
- 272.During a borescope inspection of a turbine engine compressor section, a technician finds a foreign object damage (FOD) nick 0.015 inch deep on the leading edge of a rotor blade. The maintenance manual specifies that blend repairs must have a blend length at least 10 times the blend depth to avoid a stress riser. What is the minimum blend length required for this repair?Engine Inspection
- 273.A turbine engine is equipped with accelerometers mounted on the compressor and turbine cases as part of an engine vibration monitoring system. What is the primary purpose of this system?Turbine Engines
- 274.A maintenance shop foreman explains to a new technician that a specific engine's TBO (Time Between Overhaul) is 2,000 hours. Under standard Part 91 operation, what is the significance of this figure?Reciprocating Engines
- 275.A technician measures a reciprocating engine cylinder bore at the top of ring travel and finds a diameter of 5.008 inches, and at the bottom of ring travel finds 5.000 inches. The overhaul manual specifies a standard bore diameter of 5.000 inches with a maximum allowable taper of 0.004 inch. What must the technician conclude?Engine Inspection
- 276.A mechanic is troubleshooting a Bendix RSA continuous-flow fuel injection system and needs to identify the component that senses the differential air pressure created by airflow through the venturi and uses it to meter fuel flow proportional to engine airflow demand.Fuel, Induction and Lubrication
- 277.A transport category aircraft's fuel tanks hold 450 gallons of usable Jet A fuel. Using the standard weight of 6.7 pounds per gallon for Jet A, what is the total weight of the usable fuel?Fuel, Induction and Lubrication
- 278.A technician inspects a composite propeller blade following a reported lightning strike. Which design feature is specifically built into composite blades to help protect them from lightning strike damage?Propellers
- 279.During flight through heavy rain and turbulence, a pilot selects the CONTINUOUS IGNITION switch on a turbine-powered aircraft. What is the primary purpose of this selection?Ignition and Starting Systems
- 280.During cylinder installation, a mechanic torques the cylinder base nuts to specification but fails to follow the manufacturer's specified torque sequence, tightening them randomly instead of in a star/crossing pattern. What is the primary risk of this practice?Engine Inspection
- 281.An engine's oil filter is cut open during a scheduled inspection and small metallic flakes are found trapped in the pleats. What is the primary purpose of this inspection procedure?Engine Inspection
- 282.A mechanic is inspecting the fuel primer system on a reciprocating engine used for cold-weather starting. Which statement correctly describes the function of this system?Fuel, Induction and Lubrication
- 283.A technician is comparing pitch-change mechanisms of different constant-speed propeller designs. In a Hamilton Standard hydromatic propeller, how is blade pitch changed in BOTH directions?Propellers
- 284.A pilot reports a momentary loss of engine power during a steep, uncoordinated turn in a light aircraft that was operating with low fuel quantity in one wing tank. A mechanic investigating the report determines that the fuel tank outlet was momentarily 'unported.' What does this mean?Fuel, Induction and Lubrication
- 285.A pilot is leaning the fuel/air mixture during cruise flight using an exhaust gas temperature (EGT) gauge and wants to set the mixture for best fuel economy rather than best power. According to standard leaning technique, the mixture should be set to:Reciprocating Engines
- 286.A technician sends a routine oil sample from a turbine engine for Spectrometric Oil Analysis Program (SOAP) testing. The report shows iron content has increased from 5 ppm to 45 ppm over the last three sampling intervals, while other elements remain stable. What is the most appropriate interpretation and action?Engine Inspection
- 287.A turbine engine is equipped with a starter-generator, and its control circuit includes a cutout relay. What is the primary purpose of this cutout relay?Ignition and Starting Systems
- 288.A hydraulic constant-speed propeller on a turboprop engine includes a pitch-lock mechanism. Under which condition does this mechanism engage to prevent the blades from moving toward a lower (finer) pitch angle?Propellers
- 289.An aircraft's engine oil records show that 3 quarts of oil were added after a 6-hour cross-country flight, and no leaks were found during inspection. What is the engine's oil consumption rate in quarts per hour?Fuel, Induction and Lubrication
- 290.A mechanic compares two propeller designs of the same diameter intended for high-horsepower engines with limited tip clearance. One design uses wider blades with greater total blade area (higher solidity). What aerodynamic advantage does this design provide?Propellers
- 291.A mechanic examines a propeller blade and notices the blade angle gradually decreases from root to tip. What is the purpose of this design feature?Propellers
- 292.A turboprop engine's power (free) turbine rotates at approximately 30,000 RPM, but the propeller must turn at a much lower, aerodynamically efficient speed. Which component allows the propeller to operate at this reduced rotational speed?Turbine Engines
- 293.A mechanic notes that a float-type carburetor is equipped with an accelerating pump. What is the primary purpose of this component?Reciprocating Engines
- 294.A four-cylinder horizontally opposed engine has a firing order of 1-3-2-4. Immediately after cylinder number 3 fires, which cylinder fires next?Reciprocating Engines
- 295.A turbine engine's inlet guide vanes and nose dome are protected from ice formation by circulating hot air through internal passages within these components. This anti-ice air is most commonly sourced fromTurbine Engines
- 296.A mechanic is inspecting a welded steel-tube engine mount for cracks and corrosion during an annual inspection. Which of the following findings would require the mount to be removed and repaired or replaced before further flight?Engine Inspection
- 297.A technician needs to determine N1 fan speed for cockpit indication on a turbofan engine. Which component generates the electrical signal used for this indication?Turbine Engines
- 298.During magneto internal timing, a technician sets the breaker points to open exactly when the rotating magnet is at the position producing the maximum rate of flux change. What is this position called?Reciprocating Engines
- 299.A student mechanic asks why most certificated reciprocating aircraft engines are equipped with two spark plugs per cylinder, each fired by a separate magneto. What is the primary reason for this design?Ignition and Starting Systems
- 300.What is the primary method used to cool the oil in a reciprocating aircraft engine?Reciprocating Engines