When operationally checking an autopilot system on the ground, after the aircraft's main power has been switched on, should the autopilot be engaged

When operationally checking an autopilot system on the ground, after the aircraft's main power has been switched on, should the autopilot be engaged

• A. Immediately
• B. After autopilot warms up
• C. After radar is powered
• D. Only when gyro comes up to speed and amplifier warms up

Answer: (D)

The autopilot should be engaged only after the gyro sensors have come up to operating speed and the amplifier circuits have warmed to their normal operating conditions. On the ground, the inertial reference gyros need this warm-up to produce stable, accurate attitude and heading data; until they’re up to speed, their outputs can be noisy or biased, and the autopilot could react to misleading signals. The servo amplifiers also require a brief warm-up to reach proper bias and gain, so engaging too early can lead to sluggish or erratic control commands or stress the actuators. Once both the gyros are stable and the amplifiers are warmed, the autopilot can be engaged safely for ground testing.

The autopilot should be engaged only after the gyro sensors have come up to operating speed and the amplifier circuits have warmed to their normal operating conditions. On the ground, the inertial reference gyros need this warm-up to produce stable, accurate attitude and heading data; until they’re up to speed, their outputs can be noisy or biased, and the autopilot could react to misleading signals. The servo amplifiers also require a brief warm-up to reach proper bias and gain, so engaging too early can lead to sluggish or erratic control commands or stress the actuators. Once both the gyros are stable and the amplifiers are warmed, the autopilot can be engaged safely for ground testing.