Definition
A piston aircraft engine fitted with a supercharger — an air compressor driven mechanically by the engine crankshaft (typically through gears) — that compresses intake air before it enters the cylinders. This raises manifold pressure and allows the engine to maintain rated power at altitudes where a normally aspirated engine would lose power due to thinner air.
Plain English
It's a piston engine with a built-in air pump that squeezes outside air before sending it into the cylinders. Because the engine drives the pump itself, the engine can keep making strong power higher up where the air is thin.
Context Anchor
Seen in takeoff performance discussions, especially when comparing aircraft performance at high-elevation airports or on hot days.
Derivation
‘Super-’ means ‘above or beyond,’ and ‘charge’ here refers to the fuel-air mixture loaded into the cylinder. So a supercharger gives the cylinder more than the normal charge of air. ‘Reciprocating’ comes from Latin reciprocare, ‘to move back and forth’ — describing the pistons moving up and down inside the cylinders.
Why Pilots Care
Maintains usable takeoff power at high elevations or on hot days when normally aspirated engines lose performance due to reduced air density.
Analogy
Like adding a fan to blow more air into a wood stove so the fire burns hotter and stronger even when the room air is thin.
Grounding Statement
At a high or hot airport, where normal engines may lose power because the air is thin, a supercharged reciprocating engine helps push more air into the engine for takeoff.
Intuition Check
Supercharged does not mean the engine is electrically charged or automatically unlimited in power. It means extra air is being forced into the engine so it can produce more power under the proper limits.
Example Sentence 1
Because the aircraft had a supercharged reciprocating engine, the pilot could expect closer-to-sea-level takeoff performance even from a high-elevation airport.
Example Sentence 2
At the high-elevation airport the supercharged reciprocating engine still produced full rated power while the normally aspirated engines nearby were noticeably weaker.