Gyroscopic precession

A force applied to a spinning gyro is felt 90° later, in the direction of rotation.

Push down on the rim

Or click anywhere on the disc's rim.

Force appliedWhere it's felt

Pick a spot on the rim and push it down.

Rotor

Where you'll see precession in the airplane

Propeller: raising the tail on a tailwheel airplane

The prop spins clockwise as seen from the cockpit. Raising the tail pushes the top of the prop disc forward. That force is felt 90° later in the direction of rotation, at the right side of the disc. The right side moves forward, so the nose yaws left. Be ready with right rudder.

Heading indicator drift

Friction in the gimbal bearings is a small, constant force on the gyro, so it slowly precesses away from the correct heading. That's why you check and reset the heading indicator to the magnetic compass about every 15 minutes, in straight-and-level unaccelerated flight.

Turn coordinator / turn-and-slip

These instruments use precession on purpose. When the airplane yaws or rolls, the rate gyro precesses, and that tilt moves the display to show your rate of turn.