On March 16, 2013, about 1000 eastern daylight time, an experimental Aerolite 103, N2549W, was substantially damaged when it collided with terrain near Immokalee, Florida. The private pilot sustained serious injuries. The airplane was registered to and operated by the private pilot under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight. The flight departed from Immokalee Regional Airport (IMM), Immokalee, Florida at 0900.
According to the pilot, he was returning to IMM after a short local flight. The pilot reported that he was at 3,000 feet agl and started a descent into IMM. He went on to say that he leveled off at 1,000 feet agl and had the airport insight. As he approached the airport he encountered heavy turbulence, followed by a strong gust of wind. The airplane began to descend rapidly, and he added full power in an attempt to fly out of the turbulence and climb. He did not recall if the engine's rpm increased, but stated that the airplane did not climb or perform as expected. The airplane rolled to the right, continued to descend and collided with the trees.
An examination of the airframe revealed that all of the tubing was buckled due to impact damage. Examination of the flight controls revealed continuity to the flight control surfaces. The elevator control cable was broken, and was examined by the NTSB material laboratory. The examination revealed that it was broken in overstress.
The recorded weather at the Southwest Florida International Airport, Fort Myers, Florida (RSW), revealed that at 0953, conditions were wind 170 degrees at 6 knots, cloud conditions clear, temperature 18 degrees Celsius (C); dew point 11 degrees C; altimeter 30.21 inches of mercury. According to the Federal Aviation Administration Special Airworthiness Information Bulletin (SAIB): CE-09-35; these conditions were favorable for serious carburetor icing at glide power.
A review of the ROTAX installation manual section 16) carburetor subsection 16.1) Carburetor air intake, states that "If the aircraft is to be operated in climatic conditions where carburetor icing is likely to occur, a heating system must be fitted." During the examination of the carburetor and intake system it was noted that this Rotax engine was not equipped with a carburetor heat system.
Examination of the engine revealed that the propeller blades exhibited signs of rotational damage on two of the three blades. One blade was broken off at the root and was not located.
Further examination of the engine revealed that the fuel system was breached between the primer bulb and the fuel tank. An examination of the carburetor revealed that it was impact damaged. Further examination of the carburetor system revealed that the air filter was found dirty. An examination of the spark plugs revealed that they were covered with oil deposits on the electrodes and insulator. The fuel bowl was removed and did not contain any fuel. There was evidence of water contamination but no water was within the bowl at the time of examination. The carburetor was further dissembled and the main jet was free of obstructions or blockages. The jet needle was installed correctly and was in good condition. Examination of the fuel pump revealed that it was in good condition but was mounted incorrectly according to the Rotax manual. Examination of the fuel lines revealed that they were secure to their fittings on the engine. No fuel was found between the carburetor and the fuel pump.
An examination of the cylinders revealed that there were seizure marks on the magneto piston. Metal transfers were found on the intake and exhaust side of the magneto cylinder wall. Examination of the power take-off cylinder revealed no metal transfer and no evidence of piston seizure.