Flight Design Gmbh CTSW N466CT accident near Gettysburg, Pennsylvania

Probable cause

The failure of the left main wheel attachment fitting due to overstress.

NTSB analysis

During landing, the right main landing gear touched first, followed by the left main gear which was accompanied by an audible “thump.” The left main gear collapsed and the airplane veered off the edge of the runway. The left main landing gear attachment fitting was examined at the NTSB materials laboratory and no preexisting fractures were noted. The steel fitting was constructed from tubing and bar stock, and was powder-coated after fabrication. Examination revealed that the fitting failed due to overstress midway along the angled tube portion and that the fractures were consistent with bending loads experienced during landing and taxiing. The examination further revealed that the wall thickness was less than the manufacturer's specifications, and that the interior of the angled tube had been counter-bored prior to the powered coating and final assembly at the factory. Review of the NTSB database revealed that there were two additional accidents that occurred with identical damage incurred; in all instances, the parts failed from an overstress fracture that initiated in approximately the same location.

Text from the NTSB. Open the NTSB docket for ERA09LA540 for the full record.