Rotorwash operational footprint modeling

Abstract

Wind or “rotorwash” generated by rotors, ducts, or jets affects the operational suitability and utility of future Vertical Take-Off and Landing (VTOL) aircraft. This paper presents the assessment process, environmental limits, rotorwash modeling, and output display supporting the rotorwash operational footprint model. These elements graphically combine to display the rotorwash operational impact assessment on the ground environment as contour plots or “footprints.” The tools and methodology developed were for the single main rotor helicopter, tandem helicopter, and tiltrotor configurations, but can be extended to encompass additional configurations. The rotorwash operational footprint displays the effect of winds generated by rotor thrust on the surrounding environment. These footprints can be used to evaluate compliance with aircraft performance specifications, verify safe separation distances, or influence trade studies. Future military VTOL aircraft must have a rotorwash footprint that enables mission requirements to be safely accomplished. The influences of these key factors for safe operation are captured as a suggested performance specification for future military VTOL aircraft.