Which statement about the gyro's behavior in flight instruments is true?

Which statement about the gyro's behavior in flight instruments is true?

• A. The gyro remains rigid in space as the aircraft moves
• B. The gyro precesses rapidly
• C. The gyro rotates with the aircraft
• D. The gyro is not used in flight instruments

Answer: (A)

Gyros in flight instruments are designed to stay rigid in space. A fast-spinning rotor has a large angular momentum, so its axis tends to maintain a fixed direction even as the airplane moves around it. In an attitude indicator, the rotor is mounted in gimbals, allowing the instrument’s outer frame to tilt with the aircraft while the rotor itself keeps pointing in space. This creates a stable reference: the horizon bar moves opposite the airplane’s actual motion, showing the pilot the aircraft’s attitude. The gyro doesn’t rotate with the aircraft, and while a torque can cause precession, the system is built to resist rapid precession and damp out excessive motion. Since gyros are essential to flight instruments, the statement that the gyro isn’t used is false.

Gyros in flight instruments are designed to stay rigid in space. A fast-spinning rotor has a large angular momentum, so its axis tends to maintain a fixed direction even as the airplane moves around it. In an attitude indicator, the rotor is mounted in gimbals, allowing the instrument’s outer frame to tilt with the aircraft while the rotor itself keeps pointing in space. This creates a stable reference: the horizon bar moves opposite the airplane’s actual motion, showing the pilot the aircraft’s attitude. The gyro doesn’t rotate with the aircraft, and while a torque can cause precession, the system is built to resist rapid precession and damp out excessive motion. Since gyros are essential to flight instruments, the statement that the gyro isn’t used is false.