What happened
The aircraft taxied onto the runway and the pilot advanced the engines to achieve takeoff manifold pressure of 36 inches. As the takeoff roll commenced, the pilot observed that the aircraft was accelerating more slowly than expected. In response, she reduced power to approximately 25 to 30 inches of manifold pressure.
After a brief scan of the flight instruments revealed no obvious mechanical anomalies, the pilot advanced the throttle again. A subsequent check indicated that manifold pressure had only reached 30 to 33 inches. She pushed the throttles further forward in an attempt to reach the target 36 inches of manifold pressure.
At this stage, the aircraft began to drift toward the right side of the runway. The pilot attempted to correct the yaw but was unable to regain directional control. The aircraft veered off the paved surface and collided with trees. Post-accident inspection confirmed that the flaps were set to 10 degrees.
The investigation
The examination focused on the sequence of power adjustments and the resulting handling characteristics during the critical takeoff phase. Investigators noted the discrepancy between the pilot's intended manifold pressure and the actual readings achieved during the roll.