Flight and Refueling
During a long cross-country flight, the left engine shut down in-flight and was subsequently restarted. The pilot landed and refueled the airplane. During refueling, the pilot asked the lineman if the left outboard tank was empty; the lineman confirmed it was. The pilot stated he thought he had run that tank dry and that the engine was consuming more fuel than anticipated. He purchased 55 gallons of fuel and departed.
Accident Sequence
Approximately two hours later, while maneuvering near New Philadelphia, Ohio, a review of recorded GPS data from the last four minutes of flight revealed the airplane decelerated from 110 miles per hour (mph) to 84.9 mph and descended from 1,699 feet to 923 feet before the data ended. Witnesses reported hearing the airplane experiencing engine trouble, observed it make a left turn, then roll upside down before impacting the ground.
Post-Accident Examination
Examination of the four fuel-bladder tanks revealed the left outboard tank was intact and empty. The left inboard tank was empty but breached at the engine nacelle. The right inboard tank was intact and about one-quarter full of fuel. The right outboard tank was intact with a small amount of fuel present, but fuel was observed draining from it at the accident site. The fuel selector handles were set to the outboard tanks.
Aircraft Manual Reference
According to the Piper Comanche Owner's Manual, "Vmc is the calibrated airspeed, determined by FAA test pilots, below which a twin engine aircraft cannot be controlled in flight with one engine operating at take-off power and the other engine wind milling." The Vmc for this airplane, as determined by the FAA, was 90 mph.