Elektrojets over Dübendorf 2013

This weather pattern held true on April 28 as well. The meeting began amid dreary rain. At exactly 9:30 a.m., the rain stopped, as if on cue. As usual, flight operations were able to begin right on time at 10 a.m. with light winds. At first, the sky still looked gloomy. But soon, the first bold rays of sunshine fought their way through the thick cloud cover. In a rather homeopathic dose, they illuminated the field just enough so that the pilots weren’t blinded while flying.

At first glance, the gray Venom appears to be a solid fiberglass-reinforced plastic (FRP) construction. And the Lockheed P-80 Shooting Star even gives the impression of having a carefully polished skin made of high-alloy aluminum. In reality, both aircraft are built from wood, a naturally grown raw material. To ensure that spectators still perceive the appearance as very true to the original, the surfaces were carefully covered with the appropriate film and, in the case of the P-80, additionally painted. This made it possible to successfully leverage the positive properties of this traditional building material—such as low weight, good workability, and high strength—without any visual compromises.

The impeller propulsion systems from the German company Schübler are well known among most electric jet pilots. Once again this year, the company’s CEO, Daniel Schübler, attended the Jet Meeting in person to present his latest developments in state-of-the-art CFRP technology to the assembled audience of experts. But that’s not all. There is also a very environmentally friendly and sustainable alternative in this field. For nearly 20 years now, Ueli Amacker has been building his impeller engines out of wood instead of the carbon fiber typically used

reinforced plastic. All components—including the casing, rotor, and associated blades—are made entirely from this natural material.

To ensure that the wooden blades do not shift from their designated positions on the rotor shaft due to the high centrifugal forces that occur during operation, they are...

which additionally secures them in their designated positions with carbon-fiber strands. Meanwhile, Ueli is equipping his 120-mm engines with 10 rotor blades instead of just 5. This change actually results in a slight decrease in efficiency and a minor reduction in thrust. In return, it now produces a wonderful sound. This is more reminiscent of a steady hum rather than the previous aggressive howl. The resulting sound spectrum also closely resembles the characteristic sound of the original engine, much to the delight of the pilots at the controls. On a quiet Sunday afternoon, this soft murmur is sure to win over listeners who aren’t directly involved in the flight. Incidentally, these special engines are also very popular among Ueli’s fellow Impeller pilots. At least seven aircraft were equipped with them at this event.

This year, the weather held steady throughout the rest of the day, just as the earlier forecasts had predicted. As a result, it remained dry all afternoon. Unlike last year, only a gentle breeze blew across the airfield. This provided numerous additional opportunities for free flight on the large field. Contrary to the initial fears of some pilots, the unpredictable month of April ultimately showed its truly pleasant side. Finally, on behalf of all participants, we’d like to thank organizer Nello Nero and his helpers from MG Dübendorf for the careful preparation and successful execution of this year’s Jet Meeting. Many more photos from the event can be found online at [www.telesys.ch](http://www.telesys.ch) or [www.igejs.ch](http://www.igejs.ch).

Photo and text:
Hermann Mettler