Incident Overview
A pilot reported performing an engine run-up of both engines before departure, with no discrepancies noted. The airplane then taxied to the runway. The pilot applied full power to both engines while holding the brakes, then released the brakes to begin the takeoff roll.
Takeoff and Abort
When the airplane was halfway down the 3,300-foot downsloping, wet asphalt runway, the airspeed indicator showed 60 knots. The pilot decided to abort the takeoff. During the abort, the airplane began to hydroplane on the wet surface.
Runway Overrun
The airplane continued off the end of the runway. As it approached a 15-foot drop-off, the pilot applied power to both engines, which responded. The airplane then impacted the ground in a cow pasture and came to rest upright.
Environmental Conditions
At the time of the incident, there was moderate rain.
Weight and Balance Discrepancy
Postaccident weight and balance calculations indicated that the airplane was a minimum of 359 pounds over the maximum gross weight at the time of takeoff. In contrast, calculations provided by the pilot indicated that the airplane was only 3 pounds over gross weight.