Airbus expects yet another technology demonstrator, called Racer (rapid and cost-efficient rotorcraft) to fly in the second half of 2023 after supply chain constraints forced the most recent first-flight delay from 2022.
The high-speed demonstrator, which flies as fast as 400 km/h (216 knots), features two pusher propellers mounted to a fixed double wing, or “wing box,” and a five-bladed main rotor. The unique wings actively enhance the helicopter’s performance by providing additional vertical lift and the ability to fly farther and faster than conventional helicopters. At cruise speed, roughly half the helicopter’s lift comes from its fixed wing. Meanwhile, its asymmetric tail boom produces a performance gain of up to 10 percent in hover.
A pair of 2,500-shp Safran Aneto-1X engines provide 25 percent more power than similar-size engines, according to Airbus. The demonstrator can achieve up to a 15 percent reduction in fuel burn when the pilot places one of the two engines in standby mode during cruise flight—a configuration Safran calls “eco mode.”
Racer builds on the expertise Airbus Helicopters developed with its self-funded X3 high-speed demonstrator, another compound rotorcraft design that set a speed record in June 2013 of 255 knots in forward flight.
“The X3 demonstrator showed that high speed, highly efficient results can be obtained when the main rotor’s rotational speed is slowed down during forward flight and thrust is provided by propellers mounted on a wing that provides lift,” explained Airbus Helicopters director of research and innovation Tomasz Krysinski.
For the Racer demonstrator, in part funded by the Clean Sky 2 European research program, Airbus placed the propellers on the back of the box-wing in a pusher arrangement (compared to the forward-mounted puller configuration on the X3), reducing the power required during forward flight by 10 percent, thereby further lowering fuel consumption and increasing flight range.