Accident Overview
On May 12, 2008, at approximately 1835 central daylight time, a Cessna 150M, registration N66381, struck trees and terrain near Palestine, Illinois, resulting in substantial damage to the aircraft. The private pilot, who was the sole occupant, received serious injuries. The flight was operated under 14 Code of Federal Regulations Part 91 as a personal flight in visual meteorological conditions without a flight plan. The flight originated from Daviess County Airport (DCY) in Washington, Indiana, at 1758.
Pilot Report
The pilot reported that he conducted a preflight examination at O'Neal Airport (OEA) in Vincennes, Indiana, before departure. During takeoff from OEA, the airspeed indicator indicated zero. Despite this, the pilot continued the flight, climbing to 2,200 feet mean sea level (msl) and heading toward DCY. After landing at DCY, the pilot taxied to a hangar, cleaned the airplane, and checked for obstructions. He then decided to take off and fly toward Robinson Municipal Airport (RSV) in Robinson, Illinois, and then return to OEA.
During the subsequent takeoff and climb from DCY, the airspeed indicator appeared to be functioning, but the aircraft "wanted to stall" at 60 knots indicated airspeed. The pilot lowered the pitch attitude and climbed to 2,200 feet, then reduced engine power to 1,800 rpm. Shortly thereafter, the altitude decreased to 2,000 feet and then to 1,600 feet. The pilot decided not to continue to RSV and initiated a gradual left turn to return to OEA. While descending through 1,000 feet, the stall warning horn activated. The pilot applied full power, but the airplane continued to stall. He attempted to reach a clearing beyond some woods, but the aircraft struck trees and the ground.
Flight Data Analysis
A Garmin GPSMap 396 GPS receiver was recovered from the aircraft. The recorded track data showed that after departing OEA, the airplane made several course changes and 360-degree turns with altitude variations between 2,300 and 600 feet msl before landing at DCY. The airplane remained at DCY for approximately 17 minutes before departing at 1758. After departure, the airplane remained in the airport traffic pattern and executed one landing. It then climbed to about 2,130 feet msl, stabilized at about 85 knots, and proceeded northwest toward RSV.
Approximately 5 minutes before impact, the airplane began a left-hand spiraling descent from about 1,600 feet msl. The descent consisted of six complete 360-degree left turns, ending at a recorded altitude of about 650 feet msl. The average speed during the descent was about 60 knots, with an average descent rate of about 250 feet per minute. The last recorded position, at 633 feet msl, coincided with the accident site.
Aircraft Examination
According to the sheriff's report, the occupant of the residence nearest the accident site was a relative of the pilot. Maintenance records indicated that the most recent annual inspection was performed on March 27, 2007.
Post-accident examination revealed no pre-impact anomalies with the airframe or control system components. The induction air filter had paint overspray on the filter element. Approximately 4 gallons of fuel were found in the left fuel tank, and 5 gallons in the right tank. The engine was examined: the crankshaft rotated freely, valve system continuity was established, all cylinders exhibited valve movement and produced compression, and both magnetos produced spark. The carburetor was broken loose from the induction system but showed no anomalies. Fuel was present in the carburetor float bowl and fuel lines. No anomalies that would have prevented engine operation were detected.
Weather Conditions
Weather reported at RSV at 1825 included calm winds, 10 miles visibility, clear skies, temperature 19°C, dew point 4°C, and an altimeter setting of 29.96 inches of Mercury. According to a carburetor icing probability chart, the temperature and dew point readings were favorable for moderate icing at cruise power settings and serious icing during descent power settings.