FAA AMT (Aviation Maintenance Technician) Airframe Practice Exam

What is the purpose of the lubber line on a directional gyro?

1. To indicate the aircraft's altitude

2. To represent the nose of the aircraft

3. To show engine performance

4. To measure airspeed

The correct answer is: To represent the nose of the aircraft

The correct answer is B. The purpose of the lubber line on a directional gyro is to represent the nose of the aircraft. The lubber line helps the pilot to determine the heading of the aircraft by indicating where the front of the airplane is pointing. This is important for navigation and maintaining the correct course during flight. Options A, C, and D are incorrect: A. To indicate the aircraft's altitude: Altitude is usually displayed on the altimeter, not on the directional gyro. C. To show engine performance: Engine performance is monitored through instruments like the manifold pressure gauge, RPM gauge, and engine gauges, not on the directional gyro. D. To measure airspeed: Airspeed is typically displayed on the airspeed indicator, not on the directional gyro.