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FAA Aviation Mechanic Powerplant (AMP) practice questions

335 free questions with answers and explanations.

Practice test
  1. 201.A pilot reports that a carbureted engine ran rough during descent from cruise altitude on a warm, humid day, and power was restored after applying carburetor heat, though a slight power loss occurred initially. A mechanic later inspects the induction system and finds no discrepancies. What most likely explains the initial power loss when carburetor heat was applied?Fuel, Induction and Lubrication
  2. 202.A dual-spool turbofan engine has two independently rotating compressor-turbine assemblies. Which components make up the N1 rotor system?Turbine Engines
  3. 203.A mechanic is inspecting a magnetic chip detector plug removed from an engine's oil sump. What type of debris will this device specifically attract and trap for inspection?Engine Inspection
  4. 204.A technician compares materials used in a turbofan engine's compressor and turbine sections. Which statement correctly describes typical material selection?Turbine Engines
  5. 205.During overhaul, a technician measures a reciprocating engine piston pin outside diameter at 0.8740 inch and the piston pin bore inside diameter at 0.8752 inch. The overhaul manual specifies a maximum allowable pin-to-bore clearance of 0.0010 inch. Based on these measurements, what should the technician do?Engine Inspection
  6. 206.During external timing of a magneto, a technician connects a timing light (buzz box) across the breaker points. What indication from this device tells the technician that the points have just begun to open, corresponding to the E-gap position?Ignition and Starting Systems
  7. 207.A student mechanic is asked to explain the sequence of events that occur in a gas turbine engine operating on the Brayton cycle. Which of the following lists the events in the correct order?Turbine Engines
  8. 208.During overhaul of a large single-row radial engine, a technician examines the component that has cam tracks machined on its outer circumference to actuate the valve mechanism through cam rollers and pushrods. What is this component called?Reciprocating Engines
  9. 209.A mechanic is troubleshooting a reciprocating engine that is difficult to start when hand-propped in cold weather. The magneto is equipped with an impulse coupling. What is the primary function of the impulse coupling during engine start?Reciprocating Engines
  10. 210.A technician services a fluid propeller ice-protection system that uses isopropyl alcohol distributed through a slinger ring mounted at the rear of the spinner. How does the anti-icing fluid ultimately reach the leading edge of each blade?Propellers
  11. 211.Which characteristic is a significant advantage of a centrifugal-flow compressor compared to an axial-flow compressor stage of similar diameter?Turbine Engines
  12. 212.During overhaul, a turbine engine disk is inspected using fluorescent penetrant inspection (FPI), and a linear indication is found at a bolt hole in the disk rim. Why is this finding treated with particular concern compared to a similar indication on a non-rotating case component?Engine Inspection
  13. 213.An aircraft experiences a gradual, progressive loss of manifold pressure while flying through light snow with an outside air temperature of 28°F. A mechanic later determines the cause was impact ice. Which of the following best describes impact icing?Fuel, Induction and Lubrication
  14. 214.A mechanic disassembles a cylinder and finds two types of piston rings: one set with a tapered face near the top of the piston, and a slotted ring with a spring expander near the bottom groove. What are the respective functions of these two ring types?Reciprocating Engines
  15. 215.During a scheduled inspection, a mechanic removes the magnetic chip detector plug from a turbine engine's oil sump and finds fine gray metallic fuzz adhering to the magnet. What is the appropriate next step?Fuel, Induction and Lubrication
  16. 216.A mechanic is studying the turbine section of a gas turbine engine. Which stationary component is located immediately downstream of the combustion section and directs and accelerates the hot gases onto the first-stage turbine rotor blades?Turbine Engines
  17. 217.A technician installs a spark plug whose reach (thread length) is longer than that specified for a particular cylinder. What is the most likely result?Ignition and Starting Systems
  18. 218.An aircraft operated primarily at low cruise power settings is experiencing persistent spark plug fouling. Assuming mixture leaning procedures are already correct, which spark plug characteristic should the technician review to help prevent this fouling?Ignition and Starting Systems
  19. 219.An aircraft strikes a runway light with a rotating propeller during taxi at low power. According to standard maintenance practice, what must be done regardless of visible propeller damage?Propellers
  20. 220.A pilot shuts down a fuel-injected engine after a long taxi in hot weather and, upon attempting a restart minutes later, experiences difficulty starting with erratic or no fuel flow indications. This condition is most likely caused by:Reciprocating Engines
  21. 221.A technician compares two magneto designs: one with a rotating magnet and stationary primary/secondary coils, and another with a stationary magnet and rotating armature (coil). What is the primary advantage of the rotating-magnet design used in most modern aircraft magnetos?Ignition and Starting Systems
  22. 222.A pilot reports a loud bang and a momentary flash of flame from the engine inlet during a rapid throttle advance, accompanied by a sudden drop in EPR and a brief rise in EGT. A mechanic explains this event is a compressor 'surge' rather than a localized 'stall.' What distinguishes a surge from a stall?Turbine Engines
  23. 223.A technician performing a scheduled inspection on a reciprocating engine notices the induction air filter is heavily loaded with dust and oil residue, significantly restricting airflow. What is the most likely operational effect of continuing to operate the engine with this filter condition?Engine Inspection
  24. 224.A technician overhauling a cylinder finds that the exhaust valve is equipped with a rotator mechanism (rotocoil) at the valve spring retainer. What is the primary purpose of this device?Reciprocating Engines
  25. 225.During preflight inspection on a cool, humid morning, a mechanic explains to a student why a float-type carburetor is prone to icing even when the outside air temperature is well above freezing. What is the primary cause of this icing?Fuel, Induction and Lubrication
  26. 226.A large turbofan engine on the ramp is being started using ground air supplied through a hose to the starter. Which starting system is being used, and how does it turn the engine?Ignition and Starting Systems
  27. 227.A technician performs a borescope inspection of a turbine engine's hot section and finds several turbine blades with minor leading-edge nicks and slight discoloration but no cracks or missing material. According to typical engine manufacturer criteria, what is the appropriate course of action?Engine Inspection
  28. 228.What is the fundamental difference between a wet-sump and a dry-sump lubrication system on a reciprocating engine?Reciprocating Engines
  29. 229.A technician is preparing to start a horizontally opposed reciprocating engine that has been sitting outside overnight in freezing temperatures. Company procedures require engine preheating before starting. What is the primary reason for preheating the engine under these conditions?Reciprocating Engines
  30. 230.A reciprocating engine is equipped with a direct-cranking electric starter controlled through a solenoid switch. What is the function of this solenoid?Ignition and Starting Systems
  31. 231.An older reciprocating engine ignition system includes a vibrator (booster/induction vibrator) unit used only during starting. What is the primary function of this vibrator unit?Ignition and Starting Systems
  32. 232.What is the primary purpose of tetraethyl lead (TEL) added to aviation gasoline?Fuel, Induction and Lubrication
  33. 233.A technician monitors a turbine engine start and observes that the starter disengages, EGT stays within normal limits, but N1 stabilizes well below idle speed and the engine will not accelerate further without shutting down. This is an example of a:Turbine Engines
  34. 234.A radial engine magneto drive incorporates a shear-type coupling between the accessory gear train and the magneto shaft. What is the primary purpose of this shear coupling?Ignition and Starting Systems
  35. 235.A propeller blade station is located 20 inches from the center of rotation and has a blade angle of 20 degrees at that station. What is the approximate geometric pitch at that station? (tan 20° = 0.364)Propellers
  36. 236.A technician is comparing thrust reverser designs on different turbofan engines. Which type uses hinged doors that rotate into the exhaust stream to physically block the duct and redirect exhaust gas forward?Turbine Engines
  37. 237.During a propeller inspection, a mechanic rotates a two-blade fixed-pitch aluminum propeller and marks the position of each blade tip against a fixed reference point to check tracking. If the manufacturer publishes no specific tolerance, what is the generally accepted maximum allowable difference between blade tip tracks?Engine Inspection
  38. 238.A mechanic is inspecting the inlet guide vanes of a turbine engine compressor through the inlet duct using a flashlight and finds several vanes with small dents and one vane with a visible bend that exceeds the manufacturer's blend/repair limits. What is the correct course of action?Engine Inspection
  39. 239.A mechanic is installing a propeller hub onto the engine crankshaft flange. What method should be used when torquing the mounting bolts to ensure even seating and prevent hub distortion?Propellers
  40. 240.During overhaul, a technician measures the intake valve guide bore of a cylinder using a telescoping gauge and micrometer. The measured diameter exceeds the manufacturer's maximum service limit. What is the most likely operational consequence of continuing to use this cylinder without repair?Engine Inspection
  41. 241.A technician performing an annual inspection finds that the rubber baffle seals around several cylinders on an air-cooled reciprocating engine are cracked, torn, and no longer sealing tightly against the cowling. What is the primary operational concern with this discrepancy?Engine Inspection
  42. 242.A mechanic is studying the fuel control unit (FCU) on a turbine engine to understand how fuel flow is metered during operation. Which combination of inputs does the FCU primarily use to schedule fuel flow?Fuel, Induction and Lubrication
  43. 243.During inspection of a radial engine crankshaft, a mechanic checks the dynamic counterweight (bifilar damper) assembly by hand-rocking each counterweight in its track. The rollers move noticeably more than the clearance limit specified in the overhaul manual. What action should the mechanic take?Engine Inspection
  44. 244.A mechanic is explaining the purpose of the economizer (power enrichment) system in a float-type carburetor to an apprentice. What is the primary function of this system?Fuel, Induction and Lubrication
  45. 245.A mechanic is troubleshooting a turbine engine's main fuel filter, which is equipped with a differential pressure bypass indicator. During ground run, the mechanic observes that the indicator's button has popped out. What does this indicate?Fuel, Induction and Lubrication
  46. 246.A technician is inspecting the induction system of a fuel-injected reciprocating engine equipped with a spring-loaded alternate air door. Under what condition does this door automatically open to admit unfiltered air?Fuel, Induction and Lubrication
  47. 247.A technician is preparing to hand-turn the propeller of a large radial engine that has been sitting for several days. What safety precaution addresses the risk of hydraulic lock?Reciprocating Engines
  48. 248.During an engine runup at 2,300 RPM, a technician checks the magnetos and records the following: dual RPM 2,300, left magneto only 2,150 RPM, right magneto only 2,175 RPM. The engine manufacturer specifies a maximum allowable drop of 125 RPM and a maximum differential between magnetos of 50 RPM. Based on these limits, is the magneto check within limits?Ignition and Starting Systems
  49. 249.After replacing a cylinder on a reciprocating engine, a mechanic performs an engine ground run per the maintenance manual before returning the aircraft to service. What is the primary purpose of this ground run in the context of the inspection process?Engine Inspection
  50. 250.A mechanic performs a differential compression test on a horizontally opposed engine cylinder using 80 psi input air. The cylinder reads 58/80 on the gauge, and the manufacturer's minimum acceptable value is 60/80. What should the mechanic conclude?Engine Inspection