Glossary
What is a magneto?
An engine-driven generator that produces the spark for the ignition without drawing anything from the airplane's electrical system. A piston airplane engine carries two of them, each firing its own set of plugs, so the engine keeps running if one fails or the battery goes flat.
Also called Mags
That is the whole entry for now. The longer version, with the mechanics and worked examples, is still to be written. See autorotation for how those read once they exist.