Tyrann (oz14721)

About this Plan

Tyrann. Radio control sport canard model. Pusher layout. Wingspan 990 mm.

Quote (google-translated from the German): "The idea for building this aircraft came when, while clearing the floor, I came across a delta wing that was missing the tip and motor mount after a 'standing nine'. I took the wing, down to the basement and off we went. Three days later I had the finished duck in my hand. But now the difficulties began. Where is the center of gravity in such a bird? How much engine pull and camber have to be taken into account? I was able to solve this problem later with other deltas (7) solve experiences: 0° camber, 1° sidethrust, depending on left or right turning motor.

The thing with the center of gravity was more difficult. I could not find anything in any literature on the focus of delta ducks. So the duck came into the corner and new things were started. At some point in the summer of 1979 I got ambitious. I wanted to make the machine fly. Therefore the motor was dismantled, the center of gravity estimated and trimmed with the battery. Then I drove to a meadow with very tall grass and just threw the duck into the wind. Close your eyes and wait for the expected crash. Nothing came. Open your eyes and behold, the bird lay peacefully in the grass about 20 m away. At the following starts I then shifted the center of gravity forward by 5 mm.

Later, when flying with motor power, I found that you can vary the center of gravity by about 25 mm without having a particularly negative effect on the flight characteristics. Only the inverted flight is not particularly good if the center of gravity is too far forward. The scientifically trained readers may turn up their noses at such primitive methods, in any case it worked and the bird flies. Perhaps this report is a suggestion for those to publish something in the FMT about determining the center of gravity in Delta ducks.

Building Instructions: Fuselage: Construction begins with the shafting of the side parts. I know that not everyone likes this job, but I think stocks are part of aircraft construction. If you want to avoid this work, you should look for 1.2 mm plywood in the normal wood trade. There you can often buy it very cheaply in a length of 1.5 m. But you should definitely not do without the strengthening of the side parts. Now the balsa and plywood side panels are glued together. During the drying period, the frames and auxiliary frames 10 to 19 are sawn out. The fuselage is built on a building board on the top planking..."

Direct submission to Outerzone.

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