Powerplant Theory and Maintenance Flashcards
7 cards from real AMT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Powerplant Theory and Maintenance flashcards as text
In a four-stroke reciprocating engine, during which stroke does the intake valve open and the piston move downward?
Answer: Intake stroke
During the intake stroke, the piston moves downward from TDC and the intake valve opens to draw the fuel-air mixture into the cylinder.
What is the purpose of a turbine engine's thrust reverser?
Answer: To redirect engine thrust forward to assist in decelerating the aircraft after landing
Thrust reversers redirect exhaust airflow forward, producing reverse thrust to help decelerate the aircraft during the landing roll.
Carbon monoxide poisoning risk in cabin heating systems is associated with which engine type?
Answer: Reciprocating engines using exhaust heat exchangers
Reciprocating engines that use exhaust-to-cabin heat exchangers can leak carbon monoxide into the cabin if the heat exchanger develops cracks.
What does 'brake horsepower' (BHP) measure in a reciprocating engine?
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.
Which turbine engine bearing type is most commonly used to support axial thrust loads in the main rotor shaft?
Answer: Ball bearing
Ball bearings are used to handle axial (thrust) loads in turbine engines because their design allows them to resist forces along the shaft axis.
What is the function of a propeller governor?
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.
During engine run-up, you observe that manifold pressure rises when the mixture is leaned. This indicates:
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.