Stoprotor, Hybrid Rotorwing VTOL

Gary Mortimer

Australian start up Stoprotor have an interesting concept that has moved from X Plane simulation to real world testing. Good for them!

The Hybrid RotorWing is the first VTOL aircraft to employ the use of high alpha flight controls to achieve a profile that is suitable for stopping and starting the rotor system in flight.

Aircraft designed for high alpha flight are capable of high performance maneuvers unavailable to conventional aircraft. These maneuvers are routinely flown by advanced jet fighters.

With the application of sufficient power or entry velocity, the Hybrid RotorWing can achieve high alpha flight and the required angle of attack for transition at ANY attitude. Depending on the UAV design and available power it could achieve a near level transition as demonstrated in the video below.

Previous VTOL designs have attempted to blend the often conflicting vertical flight and high performance requirements in a single aircraft with complex engineering solutions. The design of the Hybrid RotorWing has focused on simplicity of design and use of unexplored aerodynamic solutions to meet the transition requirements without the use of advanced fly by wire, vectored thrust or high power to weight configurations.

The result is a simple trade off in altitude allowing for a more efficient design and sustained, controlled flight in the transition envelope.

THE HYBRID ROTORWING HAS FIVE DISTINCT FLIGHT MODES:

Fixed Wing Flight; where the RotorWing is locked to operate as a fixed wing

Rotary Wing Flight; as a helicopter with sustained hover capability

Compound Rotary Wing Flight; where the rotors requirement to produce lift and thrust is off loaded to other lifting surfaces or propulsion engines

Autogyro Flight; any form of rotary wing flight where the rotor is driven by the relative airflow and not directly by the engine

Transition Flight Mode; where the conversion from fixed to rotary or rotary to fixed wing flight occurs

THE AIRCRAFT IS CAPABLE OF ADAPTING TO OPERATIONAL REQUIREMENTS IN THE FOLLOWING MANNER:

Conventional Take Off & Landing

Short Take Off & Landing

Vertical Take Off & Landing

Reversible In-Flight Transition

Reversible On-Ground Transition

HYBRID ROTORWING SYSTEMS

The Hybrid RotorWing has a powered main rotor, anti torque system and forward propulsion engines. These can be driven by a single engine with appropriate transmissions or multiple engines performing dedicated roles.

Power to the main rotor can take the form of direct drive via a conventional helicopter gear box, or a reaction drive system. The power source can be any combination of available power plants, eg turbine, piston or electric engines.