How does altitude generally affect engine performance?

As altitude increases, engine performance typically decreases due to the reduction in air density. At higher altitudes, the air becomes thinner, meaning there are fewer air molecules available for combustion in the engine. This lower density results in decreased oxygen levels, which negatively impacts the engine's ability to mix fuel and air effectively. Consequently, the engine produces less power as it struggles to maintain optimal combustion conditions.

This phenomenon is particularly important in aviation, where aircraft may need to perform at high altitudes for extended periods. Understanding how altitude impacts engine efficiency is crucial for pilots and ground instructors, as it informs decisions regarding aircraft performance, fuel management, and overall flight planning.