Aviation Accident Summaries

Aviation Accident Summary ANC96LA047

WASILLA, AK, USA

Aircraft #1

N50529

Cessna 150J

Analysis

A certificated flight instructor was providing a flight demonstration to a prospective student. The student occupied the left seat. Prior to departure, the airplane engine was hard to start and became flooded. While starting, flames were observed emanating from the exhaust. The pilot continued cranking the engine and the flames went out. After departure, the instructor demonstrated slow flight and a series of turns and stalls, adding carburetor heat before each reduction of engine power. During the recovery from the third full flap stall, about 2,400 feet mean sea level (msl), the first pilot lowered the nose of the airplane and added throttle. The engine did not respond and the propeller stopped. Efforts to restore engine power, including activating the engine starter were unsuccessful. The pilot selected an emergency landing area on a road but then noticed power lines along the road. He then performed a landing into trees. The airplane settled to the ground inverted. A postaccident examination of the engine did not reveal any mechanical malfunction. An AWOS weather observation, 3 miles north of the accident indicated a temperature of 47 degrees with a dew point temperature of 19 degrees.

Factual Information

On April 14, 1996, about 1510 Alaska daylight time, a wheel equipped Cessna 150J, N50529, crashed about 3 miles south of Wasilla, Alaska. The airplane was being operated as a visual flight rules (VFR) local area instructional flight when the accident occurred. The airplane, registered to Ed's Air Service, Anchorage, Alaska, and operated by the first pilot, was destroyed. The certificated commercial pilot/flight instructor (first pilot), received serious injuries. The noncertificated student pilot, (second pilot), received minor injuries. Visual meteorological conditions prevailed. The flight originated at Merrill Field, Anchorage, Alaska, about 1345. On April 15, 1996, at 1322, the second pilot reported in a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), that he was considering flight lessons and was receiving a demonstration from the first pilot. The second pilot occupied the left seat. Prior to departure, the first pilot reported that the airplane engine was hard to start and became flooded. While starting, flames were observed emanating from the exhaust. The pilot continued cranking the engine and the flames went out. The pilot continued the engine run-up and departure preparations. After departure, the first pilot reported that he demonstrated slow flight and a series of turns and stalls, adding carburetor heat control before each reduction of engine power. During the recovery from the third full flap stall, about 2,400 feet mean sea level (msl), the first pilot lowered the nose of the airplane and added throttle. The engine did not respond and the propeller stopped. Efforts to restore engine power, including activating the engine starter were unsuccessful. The pilot selected an emergency landing area on a road but then noticed power lines along the road. He then performed a landing into trees. The airplane settled to the ground inverted. The first pilot did not recall if he applied carburetor heat during the emergency descent. A Federal Aviation Administration (FAA) airworthiness inspector, Anchorage Flight Standards District Office (FSDO) responded to the scene and reported that fuel was present in the airplane's gascolator. The owner of the airplane responded to the accident scene and reported that when he arrived, the airplane's master switch and magnetos were off. The fuel selector was in the "on" position. The carburetor heat control was off. The flaps were retracted. After the airplane was recovered, an engine examination was conducted on April 16, 1996. The examination revealed engine gear and valve train continuity. Spark was produced from all towers of each magneto. The carburetor fuel inlet screen was free of contaminants. Fuel was present in the accelerator pump and dripping from the inlet air filter element. The carburetor's one piece venturi was intact and undamaged. Engine cylinder compression for the number 1 cylinder was 74/80 psi; cylinder number 2 was 12/80 psi with air heard leaking around the exhaust valve; cylinder number 3 was 73/80 psi; cylinder number 4 was 73/80 psi. The number 2 cylinder was removed and examined. The cylinder walls, piston and piston rings were undamaged. Carbon was observed on the exhaust valve seat. The closest official weather observation station is an automated weather observation system (AWOS) at Wasilla, which is located 3 nautical miles north of the accident site. At 1454, the AWOS was reporting in part: Sky condition and ceiling, clear below 12,000 feet; visibility, 10 miles; temperature, 47 degrees F; dew point, 19 degrees F; wind, 180 degrees at 5 knots; altimeter, 29.74 inHg.

Probable Cause and Findings

A loss of engine power for an undetermined reason.

 

Source: NTSB Aviation Accident Database

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