Helicopter Wake Turbulence Hazard for Light Aircraft: A Case Study

Kurzfassung

Helicopter wake turbulence poses a significant, yet often underestimated, hazard to general-aviation aircraft, particularly in airport environments. This study investigates a 2022 accident involving a Cessna 172R on final approach that potentially encountered the wake of a preceding Robinson R44 helicopter conducting a hover taxi. Utilizing both free-wake simulations and a semi-empirical probabilistic wake-vortex prediction model, the research reconstructs the aerodynamic conditions assess the potential contribution of wake turbulence to the accident. The results indicate that the helicopter generated a complex, relatively stable vortex structure with induced velocities capable of causing severe disturbances. Under plausible wind conditions, the wake vortices may have advected into the airplane's flight path, inducing critical roll and vertical motion disturbances that could have compromised the airplane controllability. The findings suggest that current separation recommendations for helicopters operating in ground effect may not be adequate for certain scenarios, indicating a need for further investigation.