What happened
The aircraft was loaded 20 pounds over the maximum gross weight limit at the time of departure. The pilot initiated the first takeoff roll but aborted the attempt after noticing the engine was running roughly. Following this abort, the pilot conducted a runup check and attempted a second takeoff. This second attempt was also aborted due to continued rough engine operation.
During the second aborted takeoff, the aircraft failed to stop on the remaining runway pavement. It overran the end of the runway and struck a ditch located just beyond the paved surface.
The investigation
Mechanics examined the engine following the accident. The inspection revealed that the engine was capable of normal operation. There were no mechanical defects found that would explain the rough running reported by the pilot during the takeoff attempts.
Findings
The density altitude at the time of the event was calculated to be 9,521 feet. This high density altitude significantly reduced aircraft performance capabilities. The combination of excess weight and high density altitude contributed to the inability to stop or become airborne safely.
The pilot's decision to attempt takeoff with an overweight condition in high density altitude conditions was a critical factor. The rough engine operation reported by the pilot was not substantiated by post-accident mechanical inspection, suggesting the issue may have been related to performance limitations rather than mechanical failure.