NTSB Factual Report

On January 30, 2005, about 0940 eastern standard time, an Aeronca S7CCM, N3069E, was substantially damaged during a forced landing after takeoff from a private airstrip near Ulster, New York. The certificated commercial pilot and the pilot rated passenger received minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed. The local personal flight was conducted under 14 CFR Part 91.

According to the pilot, the airplane's fuel tanks contained about 8 gallons of automotive fuel, and 10 gallons of 100 low lead aviation fuel that he had added on the previous day. On the day of the accident flight, he performed a preflight examination of the ski-equipped airplane, and preheated it for about 30 minutes. During the preflight, he drained fuel samples from both wing tank fuel sumps, the engine fuel bowl, and the rear fuel drain. The samples were absent of water or debris.

The engine was started, and allowed to idle for about 15 minutes. The pilot then taxied the airplane, and performed a complete run-up check. Following the takeoff, and during the initial climb and at an altitude about 50 feet above ground level (AGL), the engine began to lose power and run roughly. The pilot described the roughness as being similar to "introducing water into the carb." The engine briefly regained power and smoothed, then returned to its previous state.

With all useable runway behind him, the pilot elected to turn the airplane 90 degrees left, toward a field and an up-sloping hill. The airplane descended as it traveled across the field, at an airspeed about 50 mph. The pilot flew the airplane in parallel to the up slope of the hill, contacted the hill about 30 feet below the top, and subsequently became airborne again after crossing the crest of the hill. The airplane then continued to descend down the other side of the hill, "at near stall speed," at an altitude about 30 feet AGL. The pilot rolled the airplane into a steep bank to avoid trees, and the left wing contacted the ground. The airplane pivoted to the left, and impacted a large fence.

When the airplane came to rest, the pilot observed that the aft fuel line in the left wing had ruptured, and he had been covered with spilled fuel.

During a telephone interview, the passenger stated that as the tail of the airplane elevated during the takeoff run, the engine "sputtered." The pilot then turned the airplane left toward a hill, and it contacted the hill at an altitude about 20 feet AGL. The airplane slid up and over the hill, and became airborne again. He also believed that the engine was still running when the airplane impacted the ground. Following the accident, both he and the pilot checked the throttle control and found it to be in the full open position.

The private airport from which the airplane departed was a 2,300-foot by 100-foot snow-covered field. According to a Federal Aviation Administration (FAA) inspector, the distance from the runway to the hill that the airplane contacted was about 420 feet.

An FAA inspector conducted an examination of the engine on April 20, 2005.

One propeller blade was bent about 30 degrees aft, and exhibited leading edge damage. The other propeller blade exhibited minor nicks on the leading edge, and fore and aft faces.

Valve train continuity was confirmed to the accessory section of the engine through manual crankshaft rotation. Compression was obtained on all cylinders using the thumb method. Oil, that was dark in color, was found in the oil sump, and the oil filter element was absent of debris.

Both magnetos were intact and produced spark on all terminal leads. All spark plugs were dark in color and the bottom spark plugs were oil soaked.

The induction manifold inlet was free of obstructions, and the carburetor heat valve was found in the cold position. The carburetor was intact, and the throttle was in the full open position. The fuel inlet screen was absent of debris, and was light brown in color. The float assembly was free to move, and a small amount of debris was observed in the bowl. The bowl was absent of any liquid.

About four tablespoons of fuel were removed from the right wing fuel tank aft supply line. The liquid was green in color and no water was noted when tested with water finding paste.

Examination of the airplane's maintenance logbooks revealed that the engine was certified to use automotive gasoline.

The weather reported at Dutchess County Airport (POU), Poughkeepsie, New York, located 17 nautical miles south, at 0953, included calm winds, an overcast ceiling at 10,000 feet, temperature 27 degrees Fahrenheit, dewpoint 19 degrees Fahrenheit, and an altimeter setting of 30.12 inches of mercury.

Review of a carburetor ice probability chart revealed that the temperature and dewpoint at the time of the accident were conducive for light carburetor icing at glide or cruise power.

NTSB Probable Cause

A loss of engine power due to carburetor ice. Contributing to the accident was conditions conducive to carburetor icing.