Accident Sequence
The pilot taxied the aircraft onto the runway and advanced the throttles to achieve takeoff power, setting the manifold pressure to 36 inches. The takeoff roll was initiated, but shortly thereafter the pilot observed that the aircraft's acceleration seemed slow. She reduced the manifold pressure to between 25 and 30 inches. After scanning the instrument panel and finding no abnormal indications, she again moved the throttles forward. A subsequent check revealed that manifold pressure had only increased to between 30 and 33 inches, so she pushed the throttles further forward in an attempt to reach the original 36 inches. At that point, the aircraft began to drift to the right. The pilot attempted to correct the drift but was unsuccessful. The aircraft then veered off the runway and entered a tree line.
Aircraft Configuration
Following the event, an examination of the aircraft found that the flaps were set at 10 degrees. No other configuration information was provided in the source.
Investigation
The investigation did not state a probable cause. The documented facts include the pilot's power adjustments, the loss of directional control, and the flap setting, but no causal analysis or conclusions were offered.