What is the required practice when reconnecting a generator CSD after it has been disconnected?

• A. Reconnect in flight only
• B. Reconnect mechanically on the ground
• C. Reconnect via cockpit controls
• D. Do not reconnect

Answer: (B)

Reconnecting a generator CSD after it has been disconnected must be done mechanically on the ground. The CSD (constant speed drive) uses a mechanical clutch to couple the generator to the engine, and re-engaging this clutch while the aircraft is airborne can create a sudden torque impulse and electrical transients that the electrical system may not tolerate. On the ground, you can verify the engine and generator speeds are stable, check for faults, and ensure proper alignment before the load is re-applied.

In flight, conditions are dynamic and re-engagement could stress the drive or bus. Reconnecting through cockpit controls would be an electrical action, not the actual mechanical engagement, and is not the correct method. Not reconnecting would leave the generator out of service, which is not the required practice.