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 EdgeTM rotor blade on the Airbus Helicopters H160 helicopter. The paper covers the history and technical achievements, wind tunnel test results and flight tests.