This course covers the theory and operation of gyroscopic instruments used in aircraft. A gyroscope is a spinning wheel whose weight is concentrated around the rim and which has two properties: spatial rigidity and precession. These properties are used in attitude gyros, such as the directional gyro and the artificial horizon, and rate gyros, such as the turn and slip indicator and the turn coordinator. The course also discusses the 'degrees of freedom' of a spinning gyro, gyro stabilisation systems and the methods of powering gyros using suction or electricity. It also covers the different types of drift that can occur in gyros, including real drift, apparent drift and transport drift.