Cessna U206F N9608G accident near Igiugig, Alaska

Probable cause

The pilot’s improper decision to continue a takeoff attempt when it became evident that the airplane would not become airborne before reaching the departure end shoreline.

NTSB analysis

The pilot was attempting a takeoff in a float-equipped airplane. He estimated the gross weight of the airplane to be about 300 lbs. under the maximum gross weight limitation. He stated that after seeing the shoreline get “uncomfortably closer,” he wondered why the airplane was not getting airborne. The airplane subsequently impacted the shore, nosed over, and came to rest inverted on the beach. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.

The FAA publication Seaplane, Skiplane, and Float/Ski Equipped Helicopter Operations Handbook (FAA-H-8083-23) states that for seaplanes, as weight increases, the floats sink deeper into the water, creating a significant amount of water drag force during initial acceleration that results in a longer takeoff run.

Text from the NTSB. Open the NTSB docket for ANC21LA066 for the full record.