Plain English Meaning

Small self-powered generators on the engine that create the sparks needed to ignite fuel in the cylinders. Because they make their own electricity, the engine keeps running even if the battery fails.

Full Definition

Engine-driven electrical generators that produce high-voltage current to fire the spark plugs in a piston aircraft engine. Magnetos operate independently of the aircraft's battery and electrical system, generating their own ignition current through a rotating magnet inside a coil. Most certified piston aircraft have two magnetos (a left and a right), each firing one of the two spark plugs in every cylinder, providing and improved .