What is an important effect of altitude on aircraft engines?

As altitude increases, the air pressure and density decrease, which has a significant impact on aircraft engines. The thinner air means that there are fewer air molecules available for combustion, leading to reduced engine performance. Specifically, at higher altitudes, the engine may produce less power because it is unable to intake the necessary amount of air to maintain optimal combustion conditions. This results in a decrease in thrust and overall engine efficiency.

Additionally, as engines rely on a mixture of fuel and air for combustion, the reduction in air density can lead to a leaner fuel mixture, which may impact engine performance and temperature. Pilots must therefore carefully manage engine power settings and fuel mixtures when operating at high altitudes to maintain safe and efficient flight operations.