HS 100 Free-Flight Model by H.F.A. Schelhasse

Since engines were rarely available off the shelf at that time, the kit also included a construction plan for the engine. It was powered by a breaker-contact ignition system. This required the model to carry a fairly heavy battery. The model was constructed from plywood and pine strips. It was designed for free flight and could also be used in competitions. Apparently, there was a rule in Germany prohibiting the use of balsa wood in its construction. Balsa wood came from abroad and was therefore frowned upon under the regime in power at the time.

The HS 100 was designed by H.F.A. Schelhasse. The blueprint, along with assembly instructions, was printed by the publisher C.J.E. Volckmann, succeeded by E. Wette, Berlin-Charlottenburg. In addition to a 1:1 scale plan, there were also instructions with detailed drawings and black-and-white sketches. Incidentally, an original plan like this is currently being sold online for around 100 Fr. With the original construction, the model had a flying weight of about 3.5 kg and a wingspan of 162 cm. It was covered with either silk or tension paper and then painted several times.

The HS 100 shown here, on the other hand, was built from balsa wood and covered with film. A whisper-quiet electric motor replaces the gasoline engine. This made it possible to achieve a low flying weight of less than 2 kg, and thanks to this power system, it can now be flown even on a Sunday.

Under a beautiful spring sky, the event took place last

The maiden flight took place on our field on Sunday morning. Despite strong gusts of wind, the two very experienced model builders ventured to launch the model from the runway. The model landed back on the runway completely undamaged, which is likely due not only to skillful piloting but also to its robust landing gear. Afterward, a small yellow high-wing plane was also allowed a brief flight. But soon the wind began to play a rather rough game with it. So, between two gusts, it was quickly set down back on the runway and then packed away safely for the trip home. After the successful demonstration, I took the liberty of briefly interviewing the two successful model builders. Walter Juen had built the HS 100 himself from plans last winter at the advanced age of 83. Since he didn’t want to take any risks under the prevailing flying conditions with the glaring sunlight, he promptly handed the controls over to his son Roland.

Even though Walter no longer wants to fly it himself under these challenging flying conditions, I find the entire process of building such a model absolutely admirable. The fact that he has also rebuilt a design from his youth is, in my opinion, a truly remarkable achievement. He is one of the very few members of the MG Dübendorf who experienced model aviation firsthand back in the 1930s and 1940s and can still provide very knowledgeable insights on the subject.

Text and photo:
Hermann Mettler