Amateur-built CELEBRITY N228LC accident near Patriot, Indiana

Probable cause

An in-flight separation of the right wing due to upward and rearward bending that led to an overstress fracture. The reason for the upward and rearward bending could not be determined based on the available information.

NTSB analysis

The airline transport pilot was conducting a personal flight in his recently-purchased experimental, amateur-built biplane when the airplane experienced an in-flight breakup and subsequently impacted a cornfield. There were no witnesses to the accident. The upper and lower left wings were attached to each other but were separated from the fuselage. Part of the lower right wing was located with the wreckage but not attached to the fuselage. Additional parts of the upper and lower right wings were found scattered throughout an area between 400 yards to 800 yards west of the impact area, and other parts of the wings were found about 80 yards from the wreckage; however, the majority of the wing structure was not found.

The right wing attachment fittings displayed fractures intersecting the inboard wing spar attachment bolt hole. The fracture features for each attachment fitting were rough and matte gray in appearance, consistent with ductile overstress fracture and with upward bending of the wing at the attachment location. The outboard end of the attachment fitting piece for the aft spar was also bent aft relative to the inboard end, consistent with the entire upper and lower right wings folding upward and rearward, bending and separating from the airplane. Because this airplane is a biplane, the upward bending of the lower wing attachment was secondary to a primary failure elsewhere, the location of which could not be determined due to the fact that a majority of the wing structure was unrecovered. There was no evidence of any preexisting damage on the wing spar attachment fittings.

Text from the NTSB. Open the NTSB docket for CEN18FA282 for the full record.