From ERATO Basic Research to the Blue Edge Rotor Blade

In 2015, Airbus Helicopters unveiled the secrecy around its Dauphin successor and presented the all new H160 heli-copter. A special feature immediately attracting attention is its unusual and revolutionary fore-aft swept main rotor blade. This design, aiming at significantly reducing the blade-vortex interaction noise signature and also reducing fast forward flight power requirements, finds its origins far back in the 1990s, when DLR and ONERA formed a joint team to acoustically optimize a rectangular reference rotor blade. Based on state-of-the-art comprehensive rotor codes and a 50-50 work share, the ERATO rotor blade design was developed, patented worldwide and tested on a rotor test rig and in the wind tunnel. Airbus Helicopters (then: Eurocopter) took up that design, optimized hover and forward flight high lift performance and prepared it for serial production, until it finally made it as the Blue Edge™ rotor blade on the Airbus Helicopters H160 helicopter. The paper covers the history and technical achievements, wind tunnel test results and flight tests.