Definition
The property of a spinning gyroscope that causes it to maintain the orientation of its spin axis in space, regardless of how the supporting structure around it moves. As long as the gyro is spinning, its axis continues to point in the same fixed direction relative to space, not relative to the aircraft.
Plain English
A fast-spinning wheel resists being tipped or turned. Once it is spinning, its axis stays pointed where it was first pointed, even if the thing holding it rolls, pitches, or yaws around it.
Context Anchor
Seen in discussions of gyroscopic flight instruments, especially instruments that use a spinning gyro to help show aircraft attitude or direction.
Derivation
Rigid comes from the Latin rigidus, meaning stiff or unyielding. The gyro is not physically stiff in the usual sense; it behaves as if it were rigidly fixed in space because its spinning mass resists any change to the direction of its axis.
Why Pilots Care
This property lets gyro instruments provide stable attitude and heading references even when the aircraft banks or turns.
Analogy
Think of a spinning top. While it spins fast, it stays upright and points the same way even if you slide the table under it. Slow it down, and it starts to wobble and tip.
Grounding Statement
Picture the aircraft banking or turning while the spinning gyro inside an instrument tries to keep its own direction steady.
Intuition Check
Rigidity does not mean the part is hard or unbendable here. It means a spinning gyro resists a change in the direction its spin axis points.
Example Sentence 1
Because of rigidity in space, the attitude indicator continues to show the true horizon even as the aircraft banks and pitches around it.
Example Sentence 2
During a turn the heading indicator continues to show the correct heading because of rigidity in space until the pilot resets it.