Private Pilot Checkride Oral Practice Exam

The four strokes of an engine cycle are Intake, Compression, Power, and Exhaust. This sequence is fundamental to the operation of a four-stroke internal combustion engine.

During the Intake stroke, the engine draws in a mixture of air and fuel. This mixture is essential for the combustion process that follows. The piston moves down, creating a vacuum that allows the intake valves to open, allowing the air-fuel mixture to fill the cylinder.

Next is the Compression stroke. Here, the piston moves back up, compressing the air-fuel mixture in the cylinder. This compression increases the mixture's temperature and pressure, which is critical for efficient combustion when ignited by a spark plug.

The Power stroke follows, where the compressed mixture is ignited, resulting in a rapid expansion of gases. This explosion forces the piston down, which turns the crankshaft and provides power to the engine.

Finally, in the Exhaust stroke, the piston moves back up to expel the burnt gases from the cylinder through the exhaust valves. This helps clear the cylinder in preparation for the next cycle.

The significance of understanding this cycle lies in its application to the operation of various types of aircraft engines and the principles of flight. Knowledge of these strokes allows a pilot to comprehend how their