Helikopterfly

StopRotor Progresses with RotorWing Development

By Emma Kelly, Australia and Pacific Correspondent

Australian company StopRotor Technology says it has “attracted significant interest from industry” in progressing development of its innovative Hybrid RotorWing design, which can fly as a helicopter or fixed-wing aircraft and transition between the two.

The Sydney-based company declines to comment on development proposals, but general manager Deanne Watkins says it is also looking to work with Sydney University’s Aeronautical Engineering Faculty and Melbourne’s RMIT Sir Lawrence Wackett Aerospace Research Center in order to progress the design.

Instead of stopping the rotors in forward flight or having impractical fuselage designs, as previous vertical takeoff and landing (VTOL) designs have, the Hybrid RotorWing involves aligning the airflow with the rotation axis of the rotor while in flight, creating a stable flight profile and allowing transition between modes. The transition profile is entered by the non-rotating aerodynamic surfaces of the aircraft flying the fuselage to align the relative airflow with the rotation axis of the rotor wing. This creates and maintains symmetrical airflow that allows the RotorWing to be aerodynamically started or stopped, opening up the full potential of the stop rotor aircraft performance envelope and supporting transition.

Last year, StopRotor successfully conducted the first in-flight transition between fixed and rotary wing flight using a 2m-long prototype. A number of new prototypes are being developed for the next tests, including envelope expansion testing of conventional helicopter and compound helicopter modes. The flight control system is also being fine-tuned while the rotor wing design has been optimized. The stopped rotor allows the design to achieve efficient vertical performance and efficient forward flight from the same system, but because the rotor is stopped, they are not opposing requirements, says Watkins. StopRotor’s RotorWing will use a larger chord, higher inertia rotor system which enhances vertical lift efficiency and gives improved auto-rotation capabilities.