N999JS

On July 21, 1995, at 2045 central daylight time, a Piper PA-24-250, N999JS, piloted by a private pilot, was destroyed during a collision with trees and terrain during a forced landing. The pilot reported fuel exhaustion while on a cross country flight. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 flight was not operating on a flight plan. The pilot and one passenger reported no injuries, a second passenger was seriously injured. The flight departed Ellenville, New York, at 1715 eastern daylight time.

According to the pilot, N999JS's engine experienced a total loss of power about five minutes after he switched to the left main fuel tank. He said he switched to the left fuel tank because the right main fuel tank had run out of fuel. He said his fuel planning showed he should have had 45 minutes of fuel remaining when the engine had quit.

The pilot said he had intended to make a dead stick landing at the Watertown Municipal Airport, Watertown, Wisconsin. When he was on a one mile final for the active runway, the pilot said he realized that he was not "...going to make it." During the approach to a small field the pilot said his night vision was "destroyed" when the airplane struck an electrical powerline. The airplane touched down in a small field and then porpoised up, contacting the ground a second time. The airplane skidded to a stop and the occupants exited the airplane, according to the pilot.

The on-scene investigation was conducted by an FAA Principal Maintenance Inspector (PMI). The PMI stated he observed no usable fuel in the right and left wing's fuel bladders and wingtip tanks. He said he obtained about 1/2 ounce of fuel from the sump drain and found none in the carburetor. The PMI said there were no fuel stain marks on the airframe.

The PMI stated he found the left main fuel tank bladder's outboard top section folded over and collapsed. Approximately 30 to 35 percent of the bladder's fuel capacity was eliminated by the folded area according to the PMI. The pilot told the PMI that he put in 30 gallons of fuel in the right tank when he refueled the airplane. The pilot said he put 18 gallons of fuel in the left tank during the refueling. N999JS's normal fuel capacity was 30 gallons per main fuel tank and 15 gallons per wingtip tank. The PMI was told by the pilot that the airplane's fuel gauges did not work. The pilot said he was not aware of the folded fuel bladder.

The wing's fuel tank gauge sending units are mounted next to the wing root. Research revealed that the fuel gauge sending unit would not sense the bladder's reduced fuel capacity. The sensing unit would only sense the fuel quantity that was in the usable area as a total amount and show reduced amounts after that. The pilot, according to the PMI, said he used engine running time and his knowledge of the engine's fuel burn to calculate the remaining fuel during flight.