Amateur-built Saberwing accident near Adel, Georgia, December 18, 2018

The NTSB's narrative final · quoted from the NTSB record

The airplane broke up in-flight and the wreckage was located about 6 miles southwest from the airport, scattered over a large swamp area; there were no witnesses to the accident. Examination of the airplane revealed that the wing forward spar had two significant failure areas on both the left and right wings; one was located at the side of the fuselage and one was located at the outboard wing attach points. This was indicative of shear failure of the rear spar upper attach bolts and tensile overload at the rear spar upper spar cap. The primary wing failures were due to negative overload causing failure of the upper attach points on the left and right wings. High positive loads on the horizontal stabilizers would generate downward bending loads in the fuselage that would be greatest at the rear spar location. Given these findings, it is likely that the pilot performed a pull-up maneuver aggressively or at high speed, possibly while performing aerobatics. The pull up would have generated significant down force on the tail, resulting in the left and right fuselage longerons failing in tensile overload due to the downward bending loads in the fuselage in excess of the structural capabilities of the airplane. This sudden failure would cause the airplane to pitch over violently resulting in the negative overload wing failure.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.