IAD03FA058 · Piper PA-30

While on a long cross country flight, the left engine shut down in-flight and had to be restarted. The pilot then landed and refueled the airplane. While the airplane was being refueled, he asked the lineman if the left outboard tank was empty, and the fueler confirmed that it was. The pilot also stated that he thought that he had run the tank dry, and that the engine was burning more fuel than anticipated. He purchased 55 gallons of fuel and departed. About 2 hours later, while maneuvering near New Philadelphia, Ohio, a review of the last 4 minutes of recorded GPS data revealed the airplane had 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 heard the airplane having engine trouble, and observed the airplane make a left turn, then roll upside down, before it hit the ground. Examination of each of the four fuel-bladder tanks revealed that the left outboard tank was intact and empty, and the left inboard tank was empty, but breached at the engine nacelle. The right inboard tank was intact and about 1/4-full of fuel. The right outboard tank was intact, and a small amount of fuel was in the tank, but fuel was observed draining from the tank at the accident site. The fuel selector handles were set to the outboard tanks. 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, which the FAA had determined for this airplane, was 90 mph.

Verbatim NTSB analysis and probable cause from the NTSB dataset