Pre-accident Events
On the day of the accident, a mechanic conducted a full-power check of both engines on the runway, exercising propellers and checking magneto drops with no discrepancies. Afterward, the mechanic taxied the airplane to the fuel ramp, where the fuselage fuel tank was filled to 41.5 gallons of usable fuel. The mechanic then taxied to the ramp, secured the engines, and placed the fuel selector switches to the off position. At that time, the left wing tank had 4 to 5 gallons of fuel, and the right wing tank had 2 to 3 gallons; each wing tank’s unusable fuel amount is 3 gallons. The pilot subsequently taxied to the approach end of runway 18 and applied takeoff power.
Accident Sequence
A pilot-rated witness observed that during rotation, the airplane pitched up quickly to about 20 degrees and rolled left to 10–15 degrees of bank. The roll continued until the airplane became inverted and impacted the ground in a 40-degree nose-low attitude. A postcrash fire consumed most of the cockpit, cabin, wings, and aft fuselage, including the vertical stabilizer, rudder, and fuselage fuel tank.
Post-accident Examination
Postaccident inspection of the flight controls revealed extensive impact and fire damage but no evidence of preimpact failure or malfunction. Although flap actuators were asymmetrically extended, a restrictor in each cylinder’s downline port likely prevented rapid asymmetric movement; it is probable that the actuators moved after impact due to loss of hydraulic system pressure, not contributing to the left roll. Engines and propellers showed no preimpact failure or malfunction. The fuselage fuel sump examination found the left fuel selector in the crossfeed position, while the right fuel selector was likely in the on position (though knob positions were unreliable due to damage). The starting engines checklist directs moving both fuel selectors from on to crossfeed and back to on; the before takeoff checklist requires verifying the selectors are on. The left engine’s fuel servo injector failed flow tests, attributed to postcrash heat damage. Ground scar analysis indicated the left engine was operating just above idle, while the right engine was at about 1,315 rpm—consistent with a left engine power loss and subsequent power reduction on the right engine. Neither propeller was feathered at impact. Given the right wing tank had no usable fuel, it is unlikely the pilot moved the left fuel selector to crossfeed in response to the power loss. It is more likely the pilot failed to return the left fuel selector to the on position during the starting checklist and failed to verify it during the before takeoff checklist. Thus, the left engine drew fuel only from the right tank, which had very little fuel—enough for taxi and takeoff before the left engine failed, causing a left turn from which the pilot did not recover.
Official Probable Cause
The pilot’s failure to maintain directional control during takeoff following loss of power to the left engine due to fuel starvation. Contributing to the loss of control was the pilot’s failure to feather the left propeller following the loss of left engine power.