Amateur-built SQ 2000 N416 accident near Pierre, South Dakota

Probable cause

The airplane's entry into a pilot-induced oscillation and the pilot’s loss of airplane control during the takeoff initial climb. Contributing to the accident was the left entrance door opening in flight for undetermined reasons.

NTSB analysis

During the airplane’s initial takeoff climb, two ground witnesses observed the left “gull-wing” entrance door to be open. They reported that when the airplane was about 50 feet above the ground, it entered a series of approximately four pitch oscillations. During the last pitch-down oscillation, the airplane impacted the runway at a steep descent angle and then skidded forward about 500 feet, coming to a stop near the right side of the runway. A postimpact fire ensued. Examination of the airframe, engine, propeller and the door did not reveal any anomalies associated with a preimpact failure or malfunction.

Text from the NTSB. Open the NTSB docket for CEN12FA579 for the full record.