April 12, 2007 When you're trying to design a more efficient airplane, where do you look for inspiration? Swiss inventor Koni Schafroth looked downward. Underwater, in fact. A scale model of his fuel cell-powered HyFish project, modeled on the shape of the ocean's fastest swimmer, took flight for the first time earlier this month.

Although it might be most reminiscent of a manta ray to look at, the HyFish (as well as the battery-powered SmartFish before it) is actually modelled on the shape of the tuna. The fastest fish of them all, the tuna has been clocked at up to 85kmh in the ocean, and its shape also makes it highly manoeverable.

Refining fibreglass models that took aerodynamic cues from the tuna, Schafroth spent significant time in wind-tunnel testing with experts at Lausanne's EPFL technical University. They found the models were potentially faster and more efficient than conventional aircraft shapes of comparable size and propulsion.

Schafroth settled on a goal of producing a two-seater passenger plane capable of good airspeeds up to 900kmh, with fuel consumption to rival a VW Golf - around 10 litres per 100km.

With battery-powered scale models performing impressively in testing as early as 2002, Schafroth looked to secure investment partners. By August 2005, Team Smartfish gained a valuable new member in Ulrich Scheifer, a former aerodynamics expert on BMW's Formula One team.

Soon afterwards, Team SmartFish joined forces with the Institute for Technical Thermodynamics of the German Aerospace Centre (DLR) in Stuttgart with the goal of adapting the SmartFish's impeller engine to run on Hydrogen Fuel Cell power. The HyFish project would not only lead to a more efficient aircraft shape, it would now be emission-free.

Nineteen months later, the company has released this video of a hydrogen-powered scale model HyFish successfully taking flight. The company's ambitions for the vehicle have now expanded to include the possibility of a 20-seat commercial plane that shares the HyFish's low fuel consumption and leading-edge aerodynamics.

So keep your eye on the sky - is it a bird? A plane? It might just be a flying fish.