DON'T BELIEVE EVERYTHING – BY MAURICE BODMER

Until 1944, the only scale models built were swept-wing flying wings.

Guy Borgé, a mathematician from Lyon, had built the first “tailless” models, drawing inspiration from Fauvel’s airplanes and gliders. Airfoils with a raised trailing edge are characterized by being “self-stable.” Their center of thrust shifts only slightly if the aircraft, caught in a wake, nosedives or pitches up.

Guy, who was corresponding with Roger Stamm, had sent him the coordinates of two self-stable airfoil profiles. We tested them at the GMR events in Lausanne, Yverdon, and Vevey. The models we built flew well but had the drawback of flying very fast and, above all, having a high sink rate. While excellent for slope flying, they could not compete with flatland models—and especially not with motorized models.

In 1946, Guy took part in our model-building camp in Verbier. In the evening, in our chalet, we discussed things by candlelight. I asked Guy if it would be possible to improve the performance of our flying wings by using an S-shaped airfoil with a concave underside, as seems to be used by birds that are good gliders.

Guy asked for a pencil and a sheet of paper. And he gave us a presentation that was way over our heads, but full of double and triple integrals. And at the end, he summed it up: the finished model would go into a spin.

Roger, a third-year EPUL student, and I—who had just graduated from high school—didn’t understand a thing. It was the last evening. The next day, on Thursday, we headed home.

The following Sunday was the Philippe Jaquet Cup, named for a classmate who had drowned a year earlier in Lake Geneva. I had two days left. I quickly built a small flying wing, with an 80-cm wingspan and a hollow-bottomed airfoil.

On Sunday, my flying wing was flying, and its sink rate was normal. Thanks to the 50% bonus for flying wings, I placed 4th. But most importantly, my model had proven that we could compete with swept-wing flying wings.

• 1946 Swiss Slope Championship: 1st place—Roger Stamm (flat-bottom profile).
• 1947 Swiss Championship in Lausanne Bléchet (flat field), SK winner: Charles Baumgartner, Yverdon (Charles had a longer flight time than the best standard model).
• 1947 Flying Wing Design Competition in Langenthal: my small motorized model with a 2 cm^³ Movo engine was the only one to take off from a relatively short runway.
• And it completed three flights. Charles’s larger model would have taken off if the runway had been longer.
• Roger Stamm placed second in the glider category. He had brought only one ground-launch model. We didn’t know that takeoffs would also be made from a hill. In 1948, Roger participated in an international competition in Lognes (France), and his flatland flying wing performed very well among the standard gliders.
• Since 1969, I’ve had compass-guided flying wings (2nd place in the 1969 Swiss Championship) for slope flying.