Plain English Meaning

A group of flight instruments that work by using fast-spinning wheels inside them. A spinning wheel resists being tilted, so it stays steady while the airplane moves around it. The instruments use that steady reference to show the pilot which way the aircraft is pointed, how it's banked or pitched, and how fast it's turning.

Full Definition

Aircraft instrument systems that use spinning rotors (gyroscopes) to provide stable references for measuring or displaying attitude, heading, and rate of turn. The gyros are driven either by engine-supplied vacuum or pressure (air-driven), or by electrical power, and their resistance to changes in orientation gives the pilot a steady reference even as the aircraft .