Amateur-built Mark IV Aerobat N652DM accident near Niceville, Florida

Probable cause

The pilot's loss of control during landing for undetermined reasons.

NTSB analysis

A mechanic observed the accident pilot working on the amateur-built accident airplane the day before the accident. The pilot reported that an M8 Allen screw, which was part of the reduction gearbox, had become loose and that he was repairing it. Once the repair was made, the pilot was going to fly the airplane, but remain in the airport traffic pattern. The mechanic observed the airplane depart, but did not observe the airplane's return. An eyewitness, on a road parallel to the runway, observed the airplane flying "just above the tree tops" on the downwind leg for the south runway. She saw it turn onto the base leg and then onto the final leg, but lost sight of the airplane when it descended below the tree tops. She then heard the airplane impact the ground. The eyewitness added that the airplane did not appear "to be out of control." Examination of the airframe and engine, including the M8 Allen screw, did not reveal any preimpact mechanical malfunctions, and fuel was observed in the right wing fuel tank. The leading edge of the left wing was bent aft from the spanwise midpoint to the wingtip. The propeller blades exhibited damage consistent with rotation.

Text from the NTSB. Open the NTSB docket for NYC08FA211 for the full record.