If a CSD was disconnected due to oil over temp, can it be reconnected in flight once oil returns to normal?

• A. Yes, if oil is back to normal
• B. No, must be reset on the ground
• C. Yes, it's automatically reconnected
• D. Only by maintenance control

Answer: (B)

When a CSD trips due to oil over temperature, the drive disconnects to protect itself. Even if the oil cools back to normal, the protective latch remains until a proper reset is performed on the ground. Reconnecting in flight isn’t allowed because the fault condition must be cleared and verified by maintenance before reinitializing the CSD, ensuring oil levels, leaks, and cooling are all within limits. Re-engaging in flight could mask a underlying issue and lead to another overheating event or equipment damage. So the correct procedure is to land, have maintenance reset the CSD, and verify everything is normal before reflight.