The outer Gimbal is mounted in the case with pivot points in the fore and aft axis. The gyro is governed by the gravity. The inner gimbal is mounted in the outer gimbal with its axis athwart ship.Outer gimbals control the rolling plane bank.Inner gimbal indicates the pitch attitude.
Air driven rotor spins at 15,000 rpm.
Electric driven rotor requires a 115 v 3 phases 400 cycles A/c and provides rotor rpm of 22,550 rpm.
Freedom of movement + 85° in pitch and roll.
It suffers from following Errors:
- Acceleration shows false climb and right turn. Deceleration shows false descent and left turn.
- Turning up to 180° error is maximum On completion of 360 error is zero. On ground a tail wheel A/c, horizon bar will indicate a climbing attitude.
The gyro is governed by the gravity.
Errors:
- Acceleration Error- causes equipment to point in the North direction when a/c is accelerating and causes it to point in the South direction when a/c is decelerating.
- Turning Error- occurs when a/c is in a turn, it causes maximum error till 180° of turn and the error returns to 0 when a/c completes 360° turn.