Accident Narrative
The aircraft was on takeoff roll approximately three-quarters of the way down the runway, having just reached flying airspeed, when it encountered a soft spot that slowed the airplane. The pilot attempted to jettison the chemical load, but the dump valve would not open. At the departure end of the runway, the pilot tried to lift the aircraft into the air to clear a road. The main landing gear struck the road shoulder, causing the airplane to skip over the road. It then impacted a field and flipped onto its top approximately 50 feet south of the road.
Weight and Balance Findings
Examination of the wreckage determined that the aircraft's gross weight at the time of the accident was approximately 6,654 pounds. According to the weight and balance data in the G-164B Pilot's Operating Handbook, the maximum gross weight for the G-164B with the R-1340 engine is 5,200 pounds.
Regulatory Background
The Civil Aeronautics Manual (CAM) 8, paragraph 8.10-4 (b) 'Maximum Weight' states that establishing a maximum weight for an agricultural aircraft is not required.