Primary finding
Probable cause
The airplane’s float contacted an undetected submerged gravel bar during landing which resulted in a nose over.
Investigator assessment
Analysis narrative
While landing on a river and coming off the float step, the airplane’s float contacted an undetected submerged gravel bar in shallow water. The airplane pivoted, nosed over, and came to rest inverted. The airplane sustained substantial damage to the vertical stabilizer and rudder. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.