On September 11, 1986, a Bellanca 8GCBC (registration N86992) was involved in an aviation accident near Bradley Lake, AK. Investigators recorded the probable cause as: The pilot's inability to maintain directional control due to the rough and uneven terrain of the sand/gravel bar landing site. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot lost directional control during the landing roll on a sand and gravel bar, causing the aircraft to veer right and nose over onto its back due to rough terrain.
What happened
The incident occurred while the aircraft was conducting a landing operation on an unimproved surface. The pilot had selected a sand and gravel bar for the landing site, a location characterized by significant topographical irregularities. As the aircraft touched down and began the landing roll, the pilot encountered difficulties maintaining directional stability.
The uneven nature of the terrain proved to be a critical factor in the sequence of events. The rough surface disrupted the aircraft's traction and steering response, making it impossible for the pilot to keep the aircraft aligned with the intended path. Consequently, the aircraft veered sharply to the right. This loss of control resulted in the aircraft nosing over and coming to rest on its back.
Findings
The investigation highlighted the challenges associated with landing on unprepared surfaces. The primary contributing factor was the rough and uneven nature of the terrain, which prevented the pilot from maintaining directional control during the critical phase of the landing roll.
Probable cause
The pilot's inability to maintain directional control due to the rough and uneven terrain of the sand/gravel bar landing site.