Amateur-built 320 N360N accident near Spokane, Washington

Probable cause

Loss of airplane control due to the asymmetric flap condition.

NTSB analysis

The pilot reported that, after initiating a go-around and during a climbing left turn to re-enter the traffic pattern, his attempt to roll out of the turn was unsuccessful. The bank angle continued to near 90 degrees before he was able to maneuver the airplane close to the runway. The airplane ultimately stalled and collided with the runway surface. A postaccident examination of the airplane revealed an asymmetric flap condition. Shortly after the accident, the airplane kit manufacturer issued a Service Bulletin that addressed the asymmetric flap problem. The bulletin advised operators to inspect for adequate clearance and ensure that sufficient stiffness is established such that when fully deployed, the flap’s leading edge will not have a tendency to flex upward and snag the trailing edge of the wing. The condition could jam the flap and subsequently preclude its retraction.

Text from the NTSB. Open the NTSB docket for WPR10LA374 for the full record.