With their vertical takeoffs and landings and their ability to perform hoverhoverTHE helicoptershelicopters are quite an invention. Their advantages generate a significant disadvantage: limited speed, compared to an airplane and consumption in energyenergy colossal to keep upairair. Thus, a fast helicopter hardly exceeds 300 km/h at most. To go beyond this speed, several aircraft manufacturers have found solutions. This is the case of Lockheed-Martin with its S-97 Raider which can potentially reach 500 km/h.
Airbus Helicopters also has its demonstratordemonstrator high-speed helicopter. The Racer can theoretically reach 400 km/h and it has just made its first flight in Marignane. A simple leap, lasting around thirty minutes, the objective of which was to check the behavior of theaircraftaircraft. It was not yet a question of making a burst of speed. If it is difficult to gain speed with a helicopter, it is because of the constraints physicalphysical of the rotor which acts as a rotating blade. During flight, when turning, the end of the blade that is moving forward gains a lot of speed. Potentially, it can even reach transonic levels. For the opposite blade, it is quite the opposite and more velocityvelocity increases, the more marked the difference between the blades. Ultimately, the faster the aircraft goes, the less its rear blade ensures the liftlift necessary for the sail, hence this almost insoluble physical limit.
The Racer presentation video shows the role of the two propulsion engines placed at the end of the double beams which also act as wings. © Airbus Helicopters
A hybrid helicopter design
To address this concern, the Racer features aerodynamics optimized for high subsonic speeds. The helicopter also cheats by adding two Aneto-1X propulsion engines developed by SaffronSaffron Helicopter Engines. They are mounted at the end of double beamsbeams which look like wings on the sides of the machine. When the rotor reaches high speed, the Racer slows it down by 15%. The relay is then given to the propulsion engines and the small wings provide the lift necessary to compensate. This combination allows you to fly 50% faster than conventional helicopters. Better yet, the device would consume up to 20% less fuel thanks to this architecture. The additional motors can be activated or deactivated as needed and this is also how they significantly reduce consumption. Another important element is that the machine does not have an anti-torque rotor at the rear. Instead, we find a tailplanetailplane aircraft type with a double fin at the ends.
The Racer is part of the European project Research Clean Sky 2. As early as 2013, Airbus had already broken a speed record with the X3, a prototype which reached 472 km/h. If the racer is theoretically limited to 400 km/h it is because Airbus Helicopters seeks to obtain the best compromise between speed, profitability and mission performance. Over the next two years, the Racer will continue its testing program, with progressive testing so it can reach its top speed.
