Aviation Accident Summaries

Aviation Accident Summary CHI94LA308

KENOSHA, WI, USA

Aircraft #1

N2911

THALMAN THORP T-18

Analysis

THE AMATEUR BUILT AIRPLANE LOST ENGINE POWER SHORTLY AFTER LIFTOFF. THE PILOT WAS ABLE TO LAND THE AIRPLANE ON THE LAST 400' FEET OF RUNWAY, BUT WAS UNABLE TO STOP THE AIRPLANE BEFORE IT RAN OFF THE END AND NOSED-OVER. POSTACCIDENT EXAMINATION OF THE ENGINE AND AIRFRAME DISCOVERED NO PREIMPACT ANOMALIES. THE ENGINE WAS STARTED AND ACCELERATED TO A STATIC RPM OF 2200 WITH NO OBSERVED DEFICIENCIES. FIFTEEN MINUTES PRIOR TO THE ACCIDENT, A WEATHER REPORTING STATION 13 MILES SOUTH OF THE ACCIDENT SITE RECORDED A TEMPERATURE OF 50 DEGREES F., AND A DEWPOINT OF 47 DEGREES F. THIS TEMPERATURE/DEWPOINT COMBINATION FALLS IN THE SERIOUS ICING CATEGORY ON A CARBURETOR ICING PROBABILITY CHART. THE PILOT REPORTED HE DID NOT HAVE TIME TO ATTEMPT AN ENGINE RESTART OR TO USE THE CARBURETOR HEAT CONTROL AFTER THE ENGINE LOST POWER.

Factual Information

On September 1, 1994, about 2100 central daylight time, a Bernard J. Thalman, Jr., experimental Thorp T-18 airplane, N2911, received substantial damage following a loss of engine power during takeoff from runway 6R at the Kenosha Regional airport, Kenosha, Wisconsin. The solo private pilot was not injured. The local, 14 CFR Part 91 flight operated in visual meteorological conditions without a flight plan. The pilot reported a complete loss of engine power when the airplane reached approximately 100' AGL. He said in a telephone interview on October 26, that he did not have time to use the carburetor heat, or to attempt an engine restart. He said he was able to land the airplane on the last 400' of the runway, but was unable to stop the airplane before it ran off the end of the runway and nosed-over. A postaccident examination of the engine, fuel system, carburetor heat control, and airframe, disclosed no preimpact mechanical anomalies. The engine was started and accelerated to a static RPM of 2200 with no observed deficiencies. A weather observation taken fifteen minutes prior to the accident at the Waukeegan, Illinois, airport (approximately 13 miles south of the accident site), recorded a temperature of 50 degrees F., and a dewpoint of 47 degrees F. The attached Carburetor Icing Probability chart places this temperature/dewpoint combination in the serious icing range.

Probable Cause and Findings

the pilot's failure to use carburetor heat in carburetor icing conditions. A factor associated with the accident is the prevailing carburetor icing conditions.

 

Source: NTSB Aviation Accident Database

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