CEN15LA382

The student pilot reported that the airplane was topped off with fuel before the flight and that he completed a functional check of the carburetor heat during his pretakeoff engine run-up. Shortly after liftoff, he observed a significant decrease in engine speed, and the airplane began to descend. He reduced the pitch to increase airspeed, but the airplane descended into a cornfield about 50 ft past the end of the runway. Postaccident engine examination did not reveal any evidence of preimpact anomalies that would have precluded normal operation. Fuel samples from each wing tank, the fuel lines, the fuel strainer, and the carburetor bowl were consistent with 100 low-lead aviation fuel and did not contain any water or debris. The weather conditions were conducive to the formation of serious carburetor icing at all power settings. Additionally, the pilot reported that the grass runway was wet with dew, which likely increased the air humidity over the runway and the possibility of carburetor ice formation during taxi and takeoff. Although the pilot reported that he conducted a functional check of the carburetor heat before departure, it is likely he did not adequately ensure that the carburetor was clear of ice before beginning the takeoff. Based on the available information, the partial loss of engine power during takeoff was likely due to carburetor ice accumulation. The pilot did not have a valid pilot certificate, and his most recent student certificate had been expired for 5.5 years. Additionally, federal regulations prohibit student pilots from acting as pilot-in-command of an aircraft carrying passengers.

On August 25, 2015, about 0847 central daylight time, a Piper PA-22-160, N2805Z, collided with terrain during a forced landing shortly after takeoff from Tyler Municipal Airport (63Y), near Tyler, Minnesota. The student pilot sustained minor injuries and his two passengers sustained serious injuries. The airplane sustained substantial damage. The airplane was registered to the pilot and operated under the provisions of Title 14 Code of Federal Regulations Part 91 without a flight plan. Day meteorological conditions prevailed for the local flight that was originating at the time of the accident.The pilot reported that the purpose of the flight was to take a couple family members on a pleasure flight. He stated that he completed a preflight inspection and topped-off the fuel tanks before the flight. He started the engine about 0837 and taxied to runway 32 (2,600 ft by 160 ft, grass). The pilot noted that the grass runway was wet with dew. The pilot reported that he completed a functional check of both magnetos and the carburetor heat during a pretakeoff engine runup. The pilot stated that he selected wing flaps to 20° (half-flaps) and that about 3/4 of the available runway length was used to achieve liftoff. The pilot reported that shortly after liftoff he observed the engine speed had decreased from takeoff power to 1,900 rpm and the airplane began to descend. He reduced airplane pitch to increase airspeed, but the airplane descended into a cornfield about 50 ft past the end of the runway. The airplane and its engine were examined by a Federal Aviation Administration (FAA) airworthiness inspector and a representative from the engine manufacturer. Flight control cable continuity was established from the cockpit controls to each flight control surface. Fuel samples from each wing tank, fuel lines, fuel strainer, and the carburetor bowl were consistent with 100 low-lead aviation fuel and did not contain any water or debris. The carburetor air box was partially deformed by impact but otherwise appeared intact. The engine, a Lycoming O-320-B2A, serial number L-1872-39, remained attached to the airframe. The engine case remained intact with the accessory components still attached to their respective installation points. Internal engine and valve train continuity were confirmed as the engine crankshaft was rotated. Compression and suction were noted on all cylinders in conjunction with crankshaft rotation. Both magnetos remained attached to the engine case and provided spark on all posts while the crankshaft was rotated. The magneto timing was about 25° before top dead center. The spark plugs exhibited features consistent with normal engine operation. A borescope inspection of each cylinder did not reveal any anomalies with the cylinders, pistons, valves, or valve seats. The oil pickup screen was clear of debris. The disassembly of the carburetor revealed no water, corrosion, or debris in the bowl assembly. No anomalies were observed with the compositefloats or the needle valve. A visual examination of the carburetor fuel inlet screen revealed no evidence of debris. The postaccident examination did not reveal any anomalies that would have precluded normal engine operation during the flight. A postaccident review of available meteorological data established that day visual meteorological conditions prevailed at the accident site. The nearest aviation weather reporting station was located at Southwest Minnesota Regional Airport (MML), Marshall, Minnesota, about 17 nautical miles northeast of the accident site. At 0855, about 8 minutes after the accident, the MML automated surface observing system reported: wind 320° at 8 knots, 10 miles surface visibility, clear sky, temperature 13°C, dew point 8°C, and an altimeter setting 30.21 inches of mercury. According to a carburetor icing probability chart contained in FAA Special Airworthiness Information Bulletin CE-09-35, entitled "Carburetor Icing Prevention", the recorded temperature and dew point were in the range of susceptibility for the formation of serious carburetor icing at all engine power levels. Additionally, if ice forms in the carburetor of a fixed pitch propeller aircraft, the restriction to the induction airflow will reduce power and result in a drop of engine rpm. According to FAA airman records, the pilot did not have a valid student certificate at the time of the accident. The pilot's most recent student certificate was issued on February 15, 2005, and subsequently expired on February 28, 2010. Additionally, according to Title 14 CFR Part 61.89(a), a student pilot is prohibited from acting as pilot-in-command of an aircraft carrying passengers.