CZECH SPORT AIRCRAFT SportCruiser — Van Nuys, CA

What happened

During the instructional flight, the student pilot and flight instructor were practicing touch-and-go landings. On the third takeoff, the airplane climbed to about 430 ft above ground level (agl) and, after turning onto the downwind leg, made a 360° turn. During that time, the flight instructor reported to an air traffic controller that they were experiencing some loss of engine power. The airplane continued on the downwind leg and the controller cleared it to land on any runway. The instructor further stated that they were having exhaust gas temperature (EGT) issues. The airplane continued to descend until abeam the runway threshold and then entered a steep left bank at an altitude of about 195 ft agl. The investigation was unable to determine if the pilots banked the airplane to land on a taxilane that was perpendicular to the runway, or if they were turning an early base leg to land on a runway. The bank steepened and the airplane entered an aerodynamic stall, impacting an asphalt ramp in a near-vertical attitude.

The airplane was equipped with an engine monitoring system that would display a flashing warning and sound an audible "EXHAUST GAS TEMPERATURE" alert if the EGT exceeded the maximum EGT for the engine.

The engine was equipped with two carburetors, each containing a piston that controlled fuel delivery. Postaccident examination revealed that both carburetor piston slides were misaligned and the index tabs were not engaged, likely from improper maintenance of the assembly. This misalignment can result in engine vibrations and would likely affect the overall performance of the engine, including EGT fluctuations. The investigation was unable to determine when the carburetors were last disassembled.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.