Citation Excel (C560XL)
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Human Factors; Manuals; Procedure
I received a phone call from the Technician working the aircraft. He reported the left elevator trim actuator part number 6660161-20; had the primary drive gear installed on the wrong shaft of the actuator making it unusable for the left hand application. They had talked to Cessna Technical Support and they advised at that time it was not permissible to swap the primary gear to the other shaft. I placed another -20 actuator on order at that time. [The next day] I received another call from [the Technician] advising the second actuator they received also had the primary drive gear on the wrong side. I contacted Cessna technical support and he told me it was permissible per the CMM [Component Maintenance Manual] to swap the primary gear as long as the roll pins were replaced and loctite was reapplied. I ordered the roll pins and asked the Technician to try and swap the primary gear to the appropriate shaft per the CMM. [He] called back a little over an hour later and advised that the shaft on both actuators broke when he attempted to remove the primary gears. I placed another -20 trim actuator on order and called Cessna technical support. I told [them] what had happened with the actuator shafts when the Technician tried removing the primary gears and asked him to personally check and make sure the next trim actuator they shipped was orientated per the -20 spec before it got shipped. [The Cessna Representative] called back and advised they found an actuator that was assembled properly and it was being shipped out. He also indicated they had found four more of the -20 trim actuators that were not assembled properly and were pulled from inventory. It would appear there was a breakdown in the assembly process of the 6660161-20 trim actuator. I would suggest a follow-up with Cessna Quality Assurance asking them to advise what measures they are putting into place to assure proper assembly of the actuators to avoid further issues like this in the future.
Maintenance personnel identified that the replacement Cessna 560XL left elevator trim actuator was not properly configured. A second unit was also found to be improperly configured. After Cessna Technical Support advised a procedure to reposition the gear; the Technician damaged both units. A correctly configured unit was located but Cessna identified and removed from stock 4 additional incorrectly assembled units.