NTSB Factual Report

On June 23, 2008, about 1930 eastern daylight time, a Piper J3C-65, N4084J, was substantially damaged during a forced landing following a loss of engine power after takeoff from August Field Airport (NK17), Gansevoort, New York. The certificated private pilot/owner and the passenger sustained minor injuries. Visual meteorological conditions prevailed for the local flight that originated at NK17 about 1929. No flight plan was filed for the personal flight, which was conducted under the provisions of 14 Code of Federal Regulations Part 91.

The pilot was interviewed by telephone, and submitted a National Transportation Safety Board Form 6120.1, along with a written statement. According to the pilot, he obtained a Federal Aviation Administration (FAA) Supplemental Type Certificate (STC) to operate his airplane using automotive gasoline (STC# SA01944CH), and purchased 5 gallons of it on the way to the airport. Upon arrival, he spoke with the airport owner about the possibility that the recently purchased fuel was blended with ethanol. Because of the conversation, the pilot elected to service his airplane from a different gas can he had on hand, which contained fuel he believed was free of ethanol. The fuel service brought the total fuel onboard the accident airplane to approximately 10 gallons.

The pilot completed a preflight inspection, before-starting-engine items, and had his passenger monitor the brakes while he hand-propped the engine for start. The engine started on the second attempt, and the airplane was taxied half the length of the 2,800-foot grass runway. The pilot completed both magneto and carburetor-heat checks, and noted the anticipated 50 rpm drop for each. He then taxied into position for a southerly departure.

The pilot advanced the throttle to the full-open position, raised the tailwheel during the takeoff roll, and lifted off at 45 miles per hour. He described a shallow angle of climb at 60 to 65 knots, to between 80 and 100 feet above ground level, when the engine suddenly stopped producing power. The pilot lowered the nose, entered a 90-degree turn to the right, and struck the right wing tip on the ground as he leveled the wings for landing. The left main landing gear, then right main landing gear, collapsed at touchdown and the airplane skidded to a stop. The pilot and passenger exited the airplane, and then the pilot returned to close the fuel valve.

The pilot reported that other than the sudden loss of engine power, there were no deficiencies with the performance and handling of the airplane.

The airplane was examined by FAA aviation safety inspectors on June 24, 2008. The engine crankshaft was rotated by hand, and continuity was established through the powertrain and valvetrain to the accessory section. Compression was confirmed using the thumb method. The spark plugs were intact, and spark was produced by the magnetos at the "bottom" spark plug terminal leads.

The carburetor was broken off of the engine at impact, and examination revealed no mechanical anomalies. The filter screen was absent of debris. The fuel tank was drained, and the filter screen contained a light accumulation of debris. The shellac on the cork fuel float "showed signs of deterioration."

The pilot held a private pilot certificate with a rating for airplane single engine land. His most recent FAA third-class medical certificate was issued on July 25, 2006. The pilot reported 191 total hours of flight experience, 82 hours of which were in the Piper J3.

According to the pilot, the airplane was manufactured in 1940, and had accrued 1,238 total aircraft hours. The most recent annual inspection was completed June 5, 2008, at 1,237 aircraft hours.

At 1954, the weather reported at Floyd Bennett Memorial Airport (GFL), Glens Falls, New York, 8 miles north, included clear skies and winds from 240 degrees at 5 knots. The visibility was 10 miles. The temperature was 24 degrees Celsius and the dew point was 12 degrees Celsius.

According to an FAA Carburetor Icing Probability Chart, the atmospheric conditions at the time of the accident were on the cusp of those conducive to either "Serious Icing - glide power" or "Light Icing - glide or cruise power."

NTSB Probable Cause

A loss of engine power for undetermined reasons.