At the Paris Air Show last week, Airbus Helicopters revealed the aerodynamic configuration of the high-speed demonstrator it is developing under the Clean sky 2 European research programme.
Dubbed RACER (for Rapid And Cost-Effective Rotorcraft), the helicopter will incorporate a host of innovative features and will be optimised for a 400+km/h cruise speed. It will aim at achieving the best trade-off between speed, cost-efficiency, sustainability and mission performance. Final assembly of the demonstrator is expected to start in 2019, with a first flight the next year.
The initial impetus for development comes primarily from the civil aviation sector, but there are obvious implications here for the continued growth in military rotorcraft applications, in which sustained high speed could provide game-changing tactical advantage.
“Today we unveil our bold vision for the future of high-speed rotorcraft,” Guillaume Faury, Airbus Helicopters CEO, stated. “This new project, pulling together the skills and know-how of dozens of European partners through the Clean Sky 2 initiative, aims to bring increased speed and range at the right cost, thanks to a simple, safe and proven aerodynamic formula. It will pave the way for new time-sensitive services for 2030 and beyond, setting new benchmarks for high-speed helicopters."
The RACER demonstrator will be built around a simple architecture, ensuring safety and cost-efficiency. An innovative “box-wing” design, optimised for aerodynamic efficiency, will provide lift in cruise mode while isolating passengers during ground operations from the “pusher” lateral rotors designed to generate thrust in forward flight.
Optimised for performance and low acoustic signature, these lateral rotors as well as the main rotor will be driven by two RTM322 engines. An “eco mode” will be tested by the engine manufacturer to demonstrate an electrically-powered “start and stop” of one engine in flight, thus generating fuel savings and increasing range. The RACER demonstrator will also benefit from a hybrid metallic-composite airframe, specifically designed for low weight and low recurring costs and will be equipped with a new high voltage direct current electrical generation, which will significantly contribute to weight reduction.
Building upon the success of the self-funded X3 demonstrator, which validated the “compound” aerodynamic configuration – a combination of a traditional main rotor and innovative lateral rotors – the RACER project will bring this concept closer to an operational design and demonstrate its suitability for a wide spectrum of missions where increased speed and efficiency will bring significant added value for citizens and operators. This is especially the case for emergency medical services and search and rescue operations, as well as for public services, commercial air transport and private and business aviation.