Cessna T210M N1215M accident near Detroit Lakes, Minnesota

Probable cause

The malfunction of the right main landing gear actuator for reasons that could not be determined because postaccident examination revealed no mechanical anomalies that would have precluded normal operation. Contributing to the accident was the improper decision to disengage the landing gear system circuit breaker before the flight, which was contrary to the manufacturer-recommended procedures.

NTSB analysis

The commercial pilot reported that, before the accident flight, the airplane had been experiencing intermittent landing gear problems and that the purpose of the flight was to bring the airplane to a maintenance facility to examine the landing gear system. He added that, before the flight, the landing gear circuit breaker was pulled out "in order to keep the gear in the down position and eliminate the gear warning horn" for the flight. While landing, the pilot noticed that the left wing slightly dropped after touchdown, and the pilot corrected with aileron to maintain the runway centerline. Shortly thereafter, the pilot could feel the right main landing gear (MLG) slowly collapse. The pilot was unable to maintain the airplane on the runway centerline, and the airplane exited the runway surface. The airplane came to rest upright with the right MLG collapsed, and the right horizontal stabilizer was bent.

During a postaccident examination, the landing gear were retracted and extended multiple times. Each gear retraction was normal; however, the gear extension cycles resulted in the left MLG and nose landing gear extending and locking, and the right MLG extending with no movement from the downlock actuator. The actuator was removed for further examination, and it was difficult to move. After removal, the actuator released, and the internal spring mechanism freely moved the actuator. The actuator was disassembled with no internal problems noted.

According to the Pilot's Operating Handbook, Section 3, "Emergency Procedures, Landing Gear Malfunction Procedures," the landing gear pump circuit breaker was to be positioned to the "in" position for all landing gear malfunction scenarios.

Text from the NTSB. Open the NTSB docket for CEN17LA148 for the full record.