CHI02LA222

During initial climb the engine experienced a loss of power and the pilot executed a forced landing. During the forced landing the tailwheel contacted a power transmission line. The pilot stated he performed a check of the engine and flight controls prior to the takeoff roll, including a check of the carburetor heat, magnetos, oil pressure and engine temperatures. The pilot reported the airplane had approximately 16 gallons of fuel prior to the accident flight. The engine was test-run successfully, running smoothly at all power settings and producing a maximum rpm of 2,100. A pilot with extensive experience in the accident airplane make and model reported, "I learned many years ago that if I were sitting idling, or just [taxing], waiting for takeoff, in hot and humid air, that it was necessary to keep the carburetor heat on during idling to prevent formation of ice in the venturi throat of the carburetor. If not done, there would be a loss of power on takeoff and climb out. It takes only a minute or so for such ice accumulation to occur in some cases." According to a carburetor ice potential chart, the weather conditions were conducive for serious icing during decent power.

On July 30, 2002, at 1037 central daylight time, a White New Standard D-25, N176H, was substantially damaged during a forced landing following a reported loss of engine power near the Wittman Regional Airport (OSH), Oshkosh, Wisconsin. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot and three passengers reported no injuries, one passenger reported serious injuries. The local flight was originating at the time of the accident.

According to the pilot, the local flight was being flown in conjunction with the annual EAA AirVenture convention. The pilot reported the airplane had approximately 16 gallons of fuel prior to the accident flight. The pilot stated he performed a "normal run up including a magneto check, carb heat check, oil pressure and temperature checks." The pilot further noted he performed a "control check and everything was normal." The pilot reported, "During the takeoff roll I scanned the instrument panel and everything was normal. I began to climb and at an altitude of 60-70 feet the engine experienced a drop in power." The pilot stated, "I turned to the right to avoid hitting a restaurant and a little more to the right to go over a dip in the power lines. As I flew over the power lines the tail wheel hit the top wire."

Subsequent to the accident, inspectors with the Federal Aviation Administration performed an engine test run. The propeller was replaced with a test-club prior to the engine run. The engine started without hesitation, ran smoothly at all power settings, and developed a max rpm of 2,100.

A pilot who has extensive flight experience in the White New Standard D-25 reported, "I learned many years ago that if I were sitting idling, or just [taxing], waiting for takeoff, in hot and humid air, that it was necessary to keep the carburetor heat on during idling to prevent formation of ice in the venturi throat of the carburetor. If not done, there would be a loss of power on takeoff and climb out. It takes only a minute or so for such ice accumulation to occur in some cases."

According to a carburetor ice potential chart, developed by Transport Canada, the weather conditions were conducive for serious icing during decent power. A copy of the carburetor ice potential chart is included with the docket material associated with this accident investigation.