FAA Aviation Mechanic Airframe (AMA)Airframe Electrical and InstrumentsMedium
Which gyroscopic principle allows the attitude indicator to maintain a stable reference to the horizon regardless of the aircraft's pitch and bank changes?
- ACoriolis effect
- BPrecession
- CGyroscopic drift
- DRigidity in space
Show answer & explanationAnswer & explanation
Correct answer: D. Rigidity in space
Rigidity in space is the property of a spinning gyroscope to maintain its plane of rotation fixed in space unless acted upon by an outside force. The attitude indicator uses a gyro mounted with two gimbals (two degrees of freedom) so its spin axis stays vertical, giving a stable horizon reference as the aircraft pitches and rolls around it.
Why the other options are wrong
- A. The Coriolis effect relates to rotating reference frames, not gyro instrument operation.
- B. Precession is the tilting response to an applied force, which is actually an error source, not the stabilizing principle.
- C. Gyroscopic drift is an undesirable error, not the operating principle.
Rigidity in Space
The tendency of a spinning gyroscope to maintain the alignment of its axis of rotation in a fixed direction in space unless acted upon by an external force.
- Basis for attitude and heading indicators
- Two-degree-of-freedom gyros used for rigidity applications
- Precession is the error resulting from applied outside torque
Memory trick: Rigid gyro stands still in space like a stubborn statue