Grumman Acft Eng Cor-Schweizer G 164B N48475 accident near Marysville, California

Probable cause

The pilot's failure to adequately monitor the environmental conditions to assure the aircraft performance would afford an uneventful takeoff with the loading conditions. Contributing to the accident were the pilot's inability to jettison the load due to the dump lever being positioned inappropriately prior to takeoff, and the density altitude.

NTSB analysis

The pilot reported that while on takeoff roll with the wind calm, he noticed that the airplane had failed to gain enough speed to lift off. He then added throttle and attempted to dump the load, but the dump-stop prevented him from jettisoning the load. The pilot stated that at the very end of the runway the airplane lifted off, followed by the tailwheel impacting a small ridge, which slowed the airplane. The aircraft subsequently cleared a ditch and then started impacting young trees, with large trees directly in front of him. The pilot added that he then pulled the power off and landed in a field of young trees. The upper and lower wing panels were substantially damaged. The pilot stated that the accident could have been prevented had he made sure that the dump stop was flipped over prior to takeoff, which would have allowed the load to be dumped faster. The pilot also stated that due to the temperature having increased from what it was earlier that morning, he should have reduced his chemical load. The density altitude at the time of the accident was calculated to be about 2,042 feet mean sea level (msl); the elevation of the airstrip was about 90 feet msl. The pilot reported no mechanical malfunctions or failures with the airplane that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR14CA293 for the full record.