Not long ago, the first all-Swedish diesel-powered model took to the air above the Skarpnäck airfield near Stockholm. Svensk Flygtidning here provides a firsthand report of this landmark occasion.

The outcome was inevitable! The two model builders put their heads together. Hellström contributed his expert knowledge in the aeromodelling area and Rogstadius contributed his technical knowledge in the engine domain. Thus there was every reason to expect great things...

It took a long time to make the engine. There were many obstacles to overcome, but despite Rogstadius being called up for a period of military service, the little idea of a short time ago began to grow and, as mentioned earlier, finally reached fruition. Unfortunately, not many people were there to see its culmination, because the two model builders went out in secrecy on a Sunday morning to try out the model.

For the first flights, they used the old American method for testing engine-powered model airplanes. They simply attached a 200 ft piece of hemp cord to the model to keep it from flying too far away, because they were both fully convinced that flying was about to take place! Despite the weight of the string and the drag that it caused, the plane flew fairly well. However, Hellström had not yet been able to get the center of gravity right, so he had to wind a lot of string around the rear part of the fuselage and bind a 1/4 inch drill into the string to get the model properly balanced.

During the first test hops they couldn’t avoid breaking a number of propellers. Time and again pieces were torn off during less graceful landings and the model eventually flew with a prop that was worn down to

During the last little while, big things have occurred in the sphere of model aircraft flying. Some time ago, the first all-Swedish diesel powered model aircraft had an opportunity to try its wings in the thermals above the small Skarpnäck airfield. It was something of a sensation when two young model flying enthusiasts from Stockholm took to their bicycles and went to Skarpnäck in order to test their brand new diesel-propelled model airplane—the first all-Swedish example of its kind. If you could speak of an epochal event in the context of our relatively new aeromodelling hobby, such a word would certainly be appropriate in this situation!

The idea of building a small model equipped with a diesel engine did not come about by chance. It was born quite a while ago and originated with the Stockholm model builder and highly-praised SHT employee Gösta Hellström. The idea took shape over a long period, but despite much encouragement it did not come to fruition. It is true that some prototypes for the model were made, but the big snag continued to be the necessary small diesel engine. How to get such a thing? A few model diesel engines had found their way into our country, but they had of course been sold instantly and there were no new engines to be found.

Difficulties exist merely to be overcome and Gösta Hellström happily started out on his model—a fine little aircraft in the smallest class. It has all the characteristics that typify a Hellström model. The shape of the model is a little unorthodox, but it has beautiful lines and it is so meticulously built that you can´t find the words to express your admiration.

Eventually Hellström’s work was rewarded. Through the editor of a model magazine, Hellström established contact with another model hobby man—an expert in everything concerning model engines and a winner in numerous model engineering exhibitions. His name was Ivan Rogstadius and he too had been thinking for some time about making an all-Swedish diesel engine.

about a two inch radius, but still it flew well... It managed to take off from the ground after a fairly short run—something extraordinary to see.

After that first Sunday, there was not much to do but to repair the model, add some more trim weights and finally repair the nose section. Then they were off again for more testing, and this time they achieved results that they hardly could have dreamt of. The tether cord was omitted and the model was launched with a limited amount of fuel in the tank. The first take-offs were not so successful, but later they got the model to take off well, after which it flew in steep upward spirals to an altitude of about 70 ft. However, the glide was bad because the model stalled on its way down. Before the next start, the trim weight was moved forward and after that the flying really started! After a 5 ft ground roll the plane rose off the ground, taking smoothly to the air and climbing in a very steep spiral to an altitude of about 250 ft during 30 seconds of engine run, after which the glide started. And what a glide! The plane moved gradually towards the border of the field and soon it was outside the field limits and far away over a big forest. At once Hellström and Rogstadius got their bicycle wheels turning and went looking for the plane. When they had entered the forest they kept contact with each other through whistle signals and after about half an hour their efforts were crowned with success. An airman came up on his bicycle and asked if they were searching for the model airplane that he had just found. It seems unnecessary to describe the expressions of joy that resulted...

In this page we reproduce in print some pictures which show the little diesel model plane and its two designers. At the same time, we can announce that a detailed drawing and description of this first all- Swedish diesel model airplane will be published in an upcoming issue of SFT.