Glossary
What is a gyrocopter?
Another name for a gyroplane, and the one most people search for. It came into use as a trade name and spread to mean the type generally. Regulators write "gyroplane"; almost everyone else says gyrocopter, and they mean the same machine.
Also called Gyro
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.