Pilot Debrief

CESSNA 421C near Monroe, LA — 2022-05-15

Final reportCEN22LA202
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Date
2022-05-15
Location
Monroe, LA, USA
Airport
MLU
Aircraft
CESSNA 421C
Registration
N619AC
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Takeoff roll

Probable cause

The failure of the maintenance personnel to properly reinstall the elevator trim tab hardware, which resulted in an in-flight separation of the elevator.

NTSB narrative

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.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Maintenance personnel failed to ensure push-pull tube hardware was reinstalled.

NTSB coding

Evidence available

  • ADS-B / radar
  • Photos
  • 12 docket documents
View NTSB final reportView NTSB docket

Docket documents12

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