Cessna 195A near Pocahontas, IA — 2019-09-06

Probable cause

Overload failure of the left main landing gear during landing, which resulted in a loss of directional control.

NTSB narrative

The airline transport pilot reported that, upon landing, he immediately felt a shift to the left. The left main landing gear fractured and collapsed, and the airplane went off the runway. Postaccident metallurgical examination of the landing gear revealed that the fracture occurred from a thumbnail-shaped fatigue crack in the gear spring strut with multiple origins near the inboard attachment location at the forward edge of its upper surface. Final overstress fracture propagation direction was consistent with a downward-and-aft bending failure mode; thus, the fracture was more likely due to overload rather than the fatigue crack. This was consistent with drag loading of the left main landing gear wheel in combination with side-loading of the outboard side of the left main landing gear wheel, such as that encountered during a crosswind landing, ground loop, and/or hard left turn event. The loads experienced by the landing gear during the accident landing could not be determined, and a structural analysis was not performed to determine if the loads exceeded design load limitations.

Analysis

Primary failure mode

Mechanical failure

First missed decision gate

Pilot could have inspected landing gear before flight to prevent failure.

NTSB coding

• Part(s) separation from AC · Landing

Evidence available

• 2 docket documents

Docket documents2

• PILOT/OPERATOR AIRCRAFT ACCIDENT REPORT, NTSB FORM 6120.1form
• 20-024 MATERIALS LAB FACTUAL REPORT (CEN19LA322)report

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