Auto-giros, also known as autogyros, are aircraft that use a rotor to generate lift, much like a helicopter. However, unlike helicopters, autogyros are not powered directly by the rotor. Instead, they have an engine that provides forward thrust, and the rotor spins freely in response to air rushing over it. There are several other words that can be used to describe these unique flying machines. Some of the most common synonyms for auto-giros include gyrocopters, gyroplanes, and rotaplanes. Additionally, some people may refer to them simply as "gyros" or "autogiros," depending on their preference. No matter what you call them, autogyros continue to captivate aviation enthusiasts around the world.