Accident Sequence
The aircraft crashed while maneuvering at low airspeed and altitude shortly after takeoff. The pilot reported that the left engine began losing power intermittently at 90 knots. Despite the power loss, the pilot rotated the aircraft and attempted to continue the takeoff. Air traffic control cleared the pilot to land on any runway. While attempting a turn with the landing gear and partial flaps extended, the pilot lost control of the aircraft, resulting in a crash.
Examination Findings
An on-scene examination found no evidence of a pre-impact failure or malfunction. Both propellers exhibited torsional overload damage. Further examination of the left engine revealed that the fuel strainer was partially clogged with dirt. During a run-up test, the left engine would not develop more than 23 inches of mercury at 2,750 rpm, and the magneto rpm drop was erratic. The engine would not run with the auxiliary fuel boost pump off. The reason for the low power output was a disconnected pressure line for the turbocharger, which appeared to have been disconnected for some time.
The aircraft flight manual specifies that if an engine fails below 105 mph, the takeoff should be aborted.
Probable Cause
Occurrence #1: Loss of engine power (partial) due to mechanical failure/malfunction, specifically a blocked fuel system strainer and a disconnected turbocharger pressure line. Occurrence #2: Loss of control in flight due to improper use of flight controls and throttle/power control by the pilot in command, and failure to abort the takeoff. Occurrence #3: In-flight collision with terrain/water during maneuvering.