Cessna 210B N9637X accident near Clinton, Arkansas

Probable cause

A fatigue crack in the hydraulic actuator, which resulted in the loss of hydraulic fluid and the pilot’s inability to fully extend the landing gear.

NTSB analysis

The pilot reported that the landing gear retracted normally on takeoff; however, when he attempted to extend the landing gear in preparation for landing, the nosewheel extended and locked into place but the main landing gear did not fully extend. The pilot completed the checklist items for “landing gear emergency operation,” but the landing gear still did not fully extend and lock into place. Unable to extend the main landing gear, the pilot elected to accomplish the landing with the nosewheel extended and the main gear out of the wheel well, but not in the down-and-locked position. The pilot shut down the engine when the landing was assured to protect the engine. After the touchdown and during deceleration, the airplane rolled slightly to the left and the left elevator and horizontal stabilizer contacted the runway, which resulted in substantial damage.

Postaccident examination of the hydraulic actuator revealed a fatigue crack that initiated along the retaining ring groove of the actuator. The crack propagated in a circumferential direction outward and once the fatigue crack grew to its terminal size, the remainder of the cross-section fractured from mixed overstress and fatigue. This led to part of the housing barrel fracturing in overstress, allowing the release of the internal pressurized hydraulic fluid.

Text from the NTSB. Open the NTSB docket for CEN22LA378 for the full record.