The SR800 StopRotor prototype has been designed as a modular test bed to easily interchange different wing profiles, rotor systems and engine options.

Helicopter hover and fixed wing efficiency will be improved with a custom rotorwing design. An ‘off the shelf’ helicopter has been used in the current and previous aircraft prototypes. The test program will determine optimum rotorwing design and wing profiles to optimise overall performance.

StopRotor Program Objectives

The prime objective is to demonstrate controlled, routine starting and stopping of the rotorwing in-flight enabling transition between fixed and rotary wing flight in a single aircraft.

The air vehicle performance objectives are as follows:

• Increased aircraft hover efficiency: Retain and improve Helicopter hover efficiency with minimum compromise to achieve range and endurance targets.
• Increased aircraft cruise efficiency: Lift to drag 10:1 or greater (wind tunnel demonstrates 17:1 in clean configuration)
• Useful load & payload fraction (40% and 10-12% of gross weight respectively)
• Increased aircraft sustained flight speeds: High speed, long endurance, long range (relative to MTOW State of the art)

“To simultaneously satisfy these goals / capabilities on a single air vehicle is essential, as they exemplify the ability to improve VTOL flight speeds while also improving (or at minimum, retaining) the ability to do useful work.” DARPA 2013

StopRotor Small UAS Specifications

• Max Takeoff Weight: 20 – 25kg
• Length: 3m
• Rotor Span: 1.74m
• Canard Wing Span: 1.3m
• Rear Wing Span: 2m
• Fixed wing cruise speed target: 60kts**
• Endurance target: 12 – 15 hours**
• Payload maximum 5kg
• CTOL | STOL | VTOL

** performance metrics verified on completion of current testing activity.