Definition
A method of increasing engine power by mechanically pressurizing the air entering the cylinders, rather than relying on atmospheric pressure alone. In piston aircraft engines, forced induction is achieved with a supercharger (driven by the engine) or a turbosupercharger (driven by exhaust gases), allowing the engine to maintain sea-level power at higher altitudes where the air is thinner.
Plain English
A system that pumps extra air into the engine so it can keep making strong power, even when the surrounding air gets thin at altitude.
Context Anchor
Seen in discussions of superchargers, turbochargers, engine power at altitude, and manifold pressure management.
Derivation
From 'forced' (pushed under pressure) and 'induction' (the intake stroke that draws air into the cylinder). Together it means the intake air is pushed in under pressure rather than simply drawn in by the piston.
Why Pilots Care
It restores or increases engine power at altitude where thinner air would otherwise reduce output, directly affecting climb performance and high-altitude operations.
Analogy
It is like blowing air into a fire instead of letting the fire pull in air on its own. The extra air lets the fire burn stronger; in an engine, extra air lets more fuel burn and produce more power.
Intuition Check
Forced induction does not mean the engine is being used in an emergency or abnormal way. Here, forced means air is being pushed into the engine intake by a mechanical system.
Example Sentence 1
The aircraft's forced induction system allowed it to maintain full rated power during climb to 18,000 feet.
Example Sentence 2
Without forced induction the engine lost manifold pressure rapidly above 5,000 feet on a hot day.