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Aircraft general knowledge

8.9.7.7 Stopping the engine

We stop the engine after a flight by pulling out the mixture and thereby cutting

off the fuel supply. If we tried to stop the engine the same way we stop a car

engine, by turning the key, we would find that the engine would smell bad and

might start a few times before it stopped rotating. This would suck fuel into the
system and wash the oil out of the cylinders.

You must be careful if you want to turn the propeller, for example, because if a

wire is broken or the switch does not close, the engine will start - if the mixture

is rich.

If the mixture is lean, the aircraft engine should not start. But there might be just

the right amount of vapor to get it to light and spin once or twice.

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8.10 Other engine types

8.10.1 The diesel engine

100LL aviation fuel has become expensive to use, and our engines are not

designed to be particularly fuel efficient. This has created a need for alternative

solutions.

Flyveteori PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 751