Wake Turbulence Evolution and Hazard Analysis for General Aviation Takeoff Accident

Wake turbulence is commonly a commercial aviation topic involving relatively heavy transport aircraft. However, wake turbulence is also safety relevant for business and general aviation flight operations. A detailed analysis has been conducted for a specific accident involving two aircraft of the wake turbulence category light. A four-seat aircraft with 1 ton maximum takeoff weight took off behind a biplane with 5.5 ton maximum takeoff weight. This led to a fatal accident. Based on available information and several assumptions, the wake turbulence aspects for the specific accident scenario have been assessed. The roll axis was the dominating factor in this case. Accordingly, the wake induced rolling moment was analyzed and related to the assumed available roll control power. Furthermore, the wake vortex behavior was simulated and analyzed in detail. The results indicate that wake turbulence can be considered to be the cause of the accident. The theoretical results and the conclusions regarding the accident are also supported by the results of flight tests, which were conducted in the context of the accident investigation.