CEN22LA202

The pilot stated that, immediately after departure, he heard a loud pop and the control yoke oscillated violently. He declared an emergency and diverted to an airport with a longer runway and emergency services. The control yoke and airplane continued to oscillate until the airplane was on final approach, then the oscillation stopped. The pilot landed the airplane without further incident. A postaccident examination of the airplane revealed that the right elevator had mostly separated from the horizontal stabilizer and only a small portion of the inboard elevator remained attached. There was a small puncture on the right side of the rudder, likely from the elevator impacting the rudder when it separated in flight. The elevator trim push-pull tube remained attached to the trim actuator; however, there was no bolt, nut, or cotter pin attached to the aft fork connection, and the trim tab was missing. The push-pull tube did not exhibit any preaccident damage or anomalies. The remainder of right elevator and trim tab were not located. The elevator trim system was re-rigged two days before the accident. The maintenance personnel stated that they did not ensure that the push-pull tube hardware was reinstalled. The load applied between the push pull tube and the trim tab held the bolt in place for 4 flight hours, and it’s likely that every time there was no load on the bolt it was able to move. Once the bolt finally backed out, the trim tab would have been free to move without control. It is likely that the freely moving trim tab resulted in the airplane oscillation and ultimately the in-flight separation of the elevator.

On May 15, 2022, about 1320 central daylight time, a Cessna 421C, N619AC, was substantially damaged when it was involved in an accident near Monroe, Louisiana. The pilot and five passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that immediately after departure from Morehouse Memorial Airport (BQP), Bastrop, Louisiana, he heard a loud pop and the control yoke oscillated violently. He declared an emergency and diverted to Monroe Regional Airport (MLU), Monroe, Louisiana, about 16 miles southwest, for a longer runway and emergency services. The control yoke and airplane continued to oscillate until the airplane was on final approach, about 3 miles from MLU, then the oscillation stopped. The pilot landed the airplane without further incident. A postaccident examination of the airplane revealed that the right elevator had mostly separated from the horizontal stabilizer and only a small portion of the inboard elevator remained attached. There was a small puncture on the right side of the rudder. The elevator trim push-pull rube remained attached to the trim actuator; however, there was no bolt, nut, or cotter pin attached to the aft fork connection, and the trim tab was missing. The push-pull tube did not exhibit any preaccident damage or anomalies. The remainder of right elevator and trim tab were not located. A review of the airplane’s maintenance logbooks revealed that the elevator trim system was re-rigged on May 13, 2022, two days before the accident. The maintenance personnel who completed the work and signed off on the logbook stated that he did not ensure that the push-pull tube hardware was reinstalled. He added that he checked everything else but missed that step. The airplane had accumulated about 4 hours of flight time since the elevator trim maintenance was completed. As a result of the accident, the maintenance facility updated their company practices to include a secondary inspection sign-off and updated their work order close out procedures.