Tl Ultralight Sro STINGSPORT N404N

The pilot reported that his preflight inspection and engine run-up revealed no anomalies. During the initial climb, he noted that the airplane’s rate of climb was only 400 feet per minute (fpm); he usually had to try and keep it from exceeding 500 fpm. Shortly thereafter, the engine began to shudder. The pilot transmitted to the tower controller that he had an engine problem and was turning back, and the controller cleared him to land on any runway. The pilot maneuvered the airplane toward the runway for landing and he believed that, under normal circumstances, he would have had enough runway to complete the landing; however, the airplane’s steep descent angle and speed resulted in a bounced landing, and he stated that the airplane seemed to be gaining speed. He chose to take off again and maneuver the airplane to remain within airport property; however, the airplane did not maintain adequate speed for flight and subsequently impacted a field on airport property. The pilot shut off the fuel and electrical system and egressed the airplane. Download of data recorded by an onboard GPS unit indicated that the airplane made a right turn just after takeoff and reached a maximum altitude of 308 ft. The airplane then made a descending right turn toward the runway, crossing the runway numbers about 182 ft at a groundspeed of 62 knots (kts). With about 1,600 ft of runway remaining, the airplane’s groundspeed was 75 kts. The airplane continued past the end of the runway at a groundspeed about 57 kts. At no time did the pilot attempt to slow the airplane or increase his descent rate by slipping the airplane, extending the wing flaps or, shutting down the engine. Had the pilot taken these actions during the approach to landing, it is likely that the forced landing could have been completed successfully. Examination of the fuel system revealed that both carburetors displayed debris in the bottom of the float chambers consistent with pieces of fuel line, which were large enough to block the main jets and would affect power output of the engine at high power settings. One of the pairs of floats in one of the carburetors were also found to be heavier than specified by the engine manufacturer. One of the floats had sunk in the fuel of the float chamber, which could have resulted in a rough-running engine, loss of performance, and/or fuel leakage in the area of the carburetor. All these issues had been previously addressed through written guidance issued by the engine manufacturer. The floats installed at the time of the accident had been superseded by a newer type of float. Review of maintenance records did not indicate that any maintenance actions regarding weighing and/or replacement of the floats had ever been accomplished per the manufacturer’s written guidance, nor that the float chamber had been checked for any debris particles after fuel line replacement. The airplane had been operated 3.7 hours since its most recent condition inspection. After completion of the examinations, the debris was removed from the carburetor’s float chambers and an engine run was performed. No anomalies were noted.

Quoted verbatim from the NTSB record.