NYC99LA212

While in cruise flight at 4,500 feet msl, the engine started running rough. In order to keep the engine running smoothly the pilot had to continually reduce engine power, and at some point he added carburetor heat. With insufficient power to make an airport, the pilot made a forced landing to a grass strip. After touchdown, the airplane contacted several wire fences that crossed the strip, and entered a creek bed. The accident conditions were conducive for serious icing with glide power, and moderate icing with cruise power. No pre-impact failures or malfunction were identified with either the engine or the airframe. An engine run was preformed with the engine attached to the airframe. It started and ran smoothly.

On August 26, 1999, about 1600 eastern daylight time, a Cessna 150, N2475J, was substantially damage after a partial loss of engine power, and subsequent forced landing, in the vicinity of Madison, Ohio. The certificated private pilot and passenger were not injured. Visual meteorological conditions prevailed for the personal cross-country flight that departed Erie International Airport, Erie, Pennsylvania, destined for Frankfort Dow Memorial Field, Frankfort, Michigan. No flight plan was filed, and the flight was conducted under 14 CFR Part 91.

The pilot and passenger arrived at the airport about 1200. They fueled the airplane with auto gas. The pilot completed the preflight, noticing no anomalies. The two boarded, and the engine started on the first attempt. The pilot taxied the airplane short of the grass runway, completed the run-up checks, and remembers nothing abnormal. He then taxied onto the runway, advanced the throttle, and departed. The pilot flew down the shoreline of Lake Eire, until reaching Lake Eire International Airport where he made a planned stop to visually check the amount fuel in both wings.

After checking the fuel, they departed, and climb to 1,500 feet msl under an overcast cloud layer, while following the shoreline to the southwest. The pilot requested and received radar traffic advisories.

Once clear of the overcast, the pilot executed a climb to 4,500 feet msl. ATC then advised the pilot of weather approximately 2 miles in diameter south of the shoreline, so the pilot diverted to the north, flying out over the lake. ATC then advised him that a handoff with the next control could not be completed. Radar traffic advisories were cancelled, and about 3 minutes later, the engine started running rough.

The pilot reduced engine rpm to 2,350, and the vibration went away. Approximately 5 minutes later the engine started running rough again. The pilot applied carburetor heat. Engine rpm dropped, and the engine smoothed-out for a second time. At this point, the pilot was becoming concerned, so he turned the airplane south, directly for the shore. Because of a lower ceiling towards shore, the pilot started a descent to 3,000 feet msl. While in the descent, the engine started running rough for a third time. The pilot reduced throttle, and the vibration went away.

Once at the shoreline, the pilot turned east towards an airport he had identified on a map, but quickly realized that the airplane had insufficient power to make it. He started looking for a field, and noticed a grass strip with an airplane parked at one end. At some point, the pilot added full throttle to help slow the rate of descent, and the engine started to vibrate. He entered a left downwind for the west runway, and then positioned the airplane on final. While turning final, the pilot heard the stall warning horn sound, and then extinguish. He also felt the turn to final was a little high, but not high enough to prevent him from making his intended touchdown point.

While on short final with full flaps, the pilot identified a wire fence crossing the runway in the vicinity of his intended touchdown point. He extended his approach, missed the wire fence, and touched down. Once on the ground, he applied maximum braking, and felt the airplane start to hydroplane. Both the pilot and passenger opened their doors to increase drag. The airplane then went through another wire fence that crossed the runway, and started heading for a group of cows. The cows started to run, and the pilot applied full right rudder to avoid a collision. The airplane then passed through a third wire fence before encountering a creek, and coming to a stop. The airplane was not equipped with shoulder harnesses, and during the stop both the pilot and the passenger's headsets came off, but their upper bodies did not contact the instrument panel. The pilot added that he secured the electrical master on final, and then closed the throttle, mixture, and carburetor heat before exiting the airplane. In addition, the pilot stated that since he used auto gas in the airplane, he kept the mixture full rich throughout the entire flight to prevent damaging an exhaust valve.

According to the FAA publication, "TIPS ON WINTER FLYING," the accident conditions were conducive for serious icing with glide power, and moderate icing with cruise power. In addition, the publication stated that, "Carburetor heat should be used whenever atmospheric conditions indicate icing is a possibility and the engine is being operated at 75 percent power and below."

According to AC 20-113, "PILOT PRECAUTIONS AND PROCEDURES TO BE TAKEN IN PREVENTING AIRCRAFT RECIPROCATING ENGINE INDUCTION SYSTEM AND FUEL SYSTEM ICING," "It is...preferable to use carburetor heat or alternate air as an ice prevention means, rather than as a deicer, because fast forming ice which is not immediately recognized by the pilot may significantly lower the amount of heat available from the carburetor heating system....The use of partial heat for ice prevention without some instrumentation to gauge its effect may be worse than none at all...."

The wreckage was inspected by an FAA Inspector. During his examination he noted no pre-impact failures or malfunctions that would have contributed to a loss of power. In addition, an engine run was conducted. With the engine still attached to the airframe, it started and operated smoothly.