Witness Observations
Several witnesses observed the airplane before and during its takeoff roll on the morning of the accident. One witness, who observed the entire event, reported that the engine run-up sounded normal. During the takeoff roll, the airplane's acceleration appeared slower than usual, but the engines continued to sound normal. Directional control was maintained throughout.
Accident Sequence
The airplane did not rotate by midfield, and as it continued down the 5,132-foot runway, it did not appear to accelerate further. About 100 yards from the runway end, it seemed the airplane would not stop. It maintained contact with the runway, turned slightly right, and overran the end. The airplane was subsequently destroyed by impact forces and a postaccident fire. The wreckage was located at the bottom of a deep gully off the runway end.
Postaccident Examination
Examination of the area at the runway end revealed two distinct tire tracks crossing 175 feet of asphalt and dirt overrun. All flight control components were accounted for at the accident site. Although three witnesses indicated that the engines did not sound right at some point during the run-up or takeoff, examination of the engine and airframe revealed no evidence of any preexisting mechanical malfunctions or failures that would have precluded normal operation. Propeller signatures were consistent with rotational forces at the time of impact.
Performance Analysis
A review of the airplane's weight and balance and performance data showed it was within its maximum gross takeoff weight and center of gravity limits. At the time of the accident, the density altitude was calculated to be 7,100 feet; the airport elevation is 4,830 feet. For the weight and density altitude, the airplane should have lifted off 2,805 feet down the runway. The distance required to accelerate to takeoff speed and safely abort was calculated to be 4,900 feet. It is unknown whether the pilot completed performance calculations accounting for the density altitude. No conclusive evidence was found to explain why the airplane did not rotate or why the pilot did not abort the takeoff once reaching the point to safely stop.