Walter Enthammer, general manager of Helios Hubschraubertransport in Salzburg, Austria, has drawn on his 30 years of flying experience as a commercial helicopter pilot to develop the SilentEcoWing, an innovative new product intended to improve rotor performance.

Inspired by nature he laid the foundations for the project in 1985, mimicking the physical lift characteristics at the ends of bird's wings. "We reflected how to minimise the noise generated at the rotor blade tips," says Enthammer. "The result of this technical innovation is higher efficiency and noise reduction. A simple and economic implementation of the blade tip splits up the air flow. The vortexes diminish and the drag decreases considerably."

Previous experience as a maintenance engineer proved invaluable when what he describes as 'excessive regulations' led to a reduction in flight hours at Helios. He used the available spare time to work on the SilentEcoWing project.

"Our primary intention was to reduce the noise. But wind tunnel tests at the Technical University in Munich showed that there is also a significant rise in lift, and drag is reduced. Therefore the results were better than expected," he says.

"On a Hughes 500 D tail rotor blade which we chose for rotational tests the noise could be reduced by approximately 5 dba."

Initially he aims to license the design to manufacturers, and expects rotational tests in 2013 to be applied to the aircraft in 2014.

SilentEcoWing can be used for all aerodynamic components like airfoils, blades, propellers, rotors of helicopters, airplanes, wind power plants, racing cars and ships.

Enthammer was at the Heli Expo show recently and reports that exhibitors there were impressed. "Contacts with several companies from the US, Canada, New Zealand and Europe have been established to apply SilentEcoWing in future."