Amateur-built J D N9010T accident near Spring Valley, Ohio

Probable cause

The in-flight failure of the left wing spar, which resulted in the in-flight separation of the left wing.

NTSB analysis

The owner-designed and built experimental airplane crashed in a grass field in a rural area after the left wing separated in flight. The main wreckage included the fuselage, engine, tail surfaces, and the right wing; the left wing was located about 1/2 mile from the main wreckage. The left wing was mostly intact, but the wing control surfaces had separated. Examination of the inboard end of the left main wing spar revealed that the wood structure of the spar had failed and separated at the spar attachment bolt locations. No witnesses to the accident flight were identified; however, it is likely that the pilot was maneuvering when the wing separation occurred. Because the airplane was a unique design and investigators did not have access to the design parameters, it was not possible to determine precisely why the wing spar failed. Postaccident examination of the airframe revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation other than the separated wing spar previously described. Based on the available evidence, it is likely that the left wing spar failed and resulted in an in-flight separation of the wing and the airplane’s subsequent impact with the ground.

Text from the NTSB. Open the NTSB docket for CEN12LA349 for the full record.