Aviation Accident Summaries

Aviation Accident Summary CHI97LA179

CUMBERLAND, IN, USA

Aircraft #1

N9842J

Cessna A150M

Analysis

The pilot noticed the engine wasn't producing '...sufficient power to sustain flight' during the initial climb after takeoff. He said the engine was running rough during the climb. Also, he said the airplane stalled and rolled to the left shortly after he applied elevator back pressure to avoid a barn in front of the airplane. The airplane collided with the ground in a nose low attitude, while in a shallow left bank. An on-scene investigation revealed no mechanical anomaly with the airframe or engine that would have prevented normal flight. The throttle was found in the 'FULL' power position, and the carburetor heat was in the 'OFF' position. The temperature (80 degrees F) and dew point (70 degrees F) were conducive to carburetor icing. The carburetor throat and 2 spark plugs were sooted.

Factual Information

On June 23, 1997, at 1930 eastern daylight time (edt), a Cessna A150M, N9842J, piloted by a commercial pilot, was substantially damaged when it collided with the ground during an uncontrolled descent following a pilot-reported stall. 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 passenger reported no injuries. The flight departed a restricted landing area near Cumberland, Indiana, at 1928 edt. The pilot said the airplane's engine was not producing "...sufficient power to sustain flight..." after takeoff. He said the engine was running rough during a turn the airplane made shortly after takeoff. He said he "...took evasive action to avoid a woods, a tree, and a barn. The airplane was then force landed in a corn field." The airplane came to rest in a field containing two foot high corn. During an interview with the pilot, he said the airplane was not climbing right because the engine was running rough. He said the airplane was about 50 to 75 feet above the ground when he saw a barn in front of the airplane. He said he applied elevator back pressure to fly over the barnafter which the airplane stalled and rolled to the left. He said he then applied forward elevator pressure and right rudder. The pilot said the airplane collided with the ground at a 10 to 15 degree nose low angle in a shallow left bank. The pilot said he did a pre-takeoff engine magneto check at 1,800 RPM. He said he did the magneto check by switching the magnetos from "BOTH" to the "RIGHT" magneto, then to the "LEFT" magneto, returning the switch back to "BOTH." He said he noticed a little roughness during the magneto check and leaned the mixture control. He said the roughness disappeared. The pilot said the engine guages were all in the green during the takeoff and initial climbout. According to an Indiana State Police accident report, a witness heard the engine sputtering and saw the airplane "...losing altitude before striking the ground with the left wing." During an interview with the Federal Aviation Administration Principal Operations Inspector (POI), the pilot said the airplane's engine was operating on the ground for about 5 minutes. According to the POI, the pilot stated the engine had idled about 2 minutes before takeoff. According to the POI, inspection of the airplane revealed the carburetor heat was in the "OFF" position, the throttle was in the "FULL" throttle position, the mixture was full "RICH", and the fuel selector valve was in the "OFF" position. He said the engine had mechanical continuity throughout and that both magnetos created spark when rotated. The POI said he observed black sooting in the carburetor's throat and on the top spark plugs of cylinders' 1 and 3. He said the remainder of the spark plugs "...were found in good condition." The airplane's airframe and powerplant logbooks showed its last annual was May 1, 1996. The pilot said the outside air temperature was between 80 and 85 degrees Fahrenheit. About 30 minutes before the accident, Indianapolis International Airport, Indianapolis, Indiana, reported the temperature/dewpoint as 80 and 70 degrees Fahrenheit respectively. This airport is located about 25 miles west of the accident site. According to the carburetor icing chart found in FAA publication FAA-P-8740-24, N9842J was operating in atmospheric conditions that would be conducive to serious carburetor icing with glide power. N9842J's left wing was crushed aft between the leading edge and main spar from the wingtip to about the aileron's mid-span position. This area was bent upward about 10 degrees. The right wingtip was crushed inward from the tip to the first wing rib inboard of the tip. The right main landing gear and nose wheel assembly had separated from the airframe. The fuselage tail cone had partially separated from the fuselage at the rear window. It was angled about 75 degrees to the left of the airplane's center line.

Probable Cause and Findings

the pilot's failure to use (or improper use of) carburetor heat. Factors associated with the accident were: carburetor icing (weather) conditions, and the lack of airspeed (or altitude) to clear an obstruction (barn) without stalling the airplane.

 

Source: NTSB Aviation Accident Database

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