Accident Overview
On January 1, 2010, at approximately 1108 eastern standard time, a Cessna 150G, registration N4026J, experienced a partial loss of engine power during climb after departing Doylestown Airport (DYL) in Doylestown, Pennsylvania. The flight was a personal local operation under 14 CFR Part 91, with visual meteorological conditions prevailing and no flight plan filed. The aircraft sustained substantial damage, but the certificated commercial pilot and one passenger were not injured. The flight had originated from DYL about 1106.
Pilot Account
The pilot stated that the purpose of the flight was to evaluate the airplane following extensive engine maintenance. He intended to orbit the airport for one hour before landing to allow a mechanic (the passenger) to visually inspect the engine. Preflight checks indicated approximately 6 gallons of 100 low lead (100LL) fuel in each fuel tank, confirmed by dipstick and fuel quantity gauges. No contaminants were found in the fuel tanks or gascolator, and no discrepancies were noted during the engine run-up before takeoff.
During climb out, at an altitude between 50 and 75 feet above ground level, the pilot noticed a partial loss of engine power. With trees ahead, he turned right toward an open field. During the turn, the right main landing gear contacted the ground, followed by the left main landing gear, causing the landing gear to separate. The airplane came to rest upright in a left wing low attitude, with fuel leaking from the left fuel cap.
Post-Accident Examination
An FAA inspector examined the accident site. The airplane was resting in the middle of a corn field with the left and nose landing gears separated. A small fire in the engine compartment had been quickly extinguished. The aircraft was recovered for further examination.
After recovery, an FAA airworthiness inspector examined the engine. The air induction housing was crushed around the carburetor, but the air induction system showed no obstructions. The air induction filter, which had separated and was recovered from the site, was found to have been properly installed. The throttle, mixture, and carburetor heat control cables were connected and properly attached, though impact damage prevented range-of-motion checks. The carburetor's accelerator pump operated satisfactorily. Spark plugs were new with light gray porcelain insulator coloration. The engine was rotated by hand; spark was observed at all spark plugs, and compression was noted in all cylinders. No evidence of failure or malfunction was found in the muffler.
Weather and Conditions
A surface observation weather report from DYL at 1054, about 14 minutes before the accident, indicated a dry bulb temperature of 35°F, dew point of 33°F, and relative humidity of 92 percent. According to FAA Special Airworthiness Information Bulletin (SAIB) CE-09-35, based on the recorded temperature and dew point around the time of the accident, conditions were favorable for serious carburetor icing at cruise power settings. Additionally, FAA Advisory Circular (AC) 20-113 notes that induction system icing is more likely when temperature is below 70°F and relative humidity exceeds 80 percent.
Additional Details
An overhauled engine had been installed the day before the accident and test run after installation. The recording tachometer read 6,275.32 hours at installation and 6,275.41 hours at the time of the accident.