Fujavak (oz15181)

About this Plan

Fujavak. Radio control powered glider. Wingspan 60 in, for .049 - .15 engine.

Direct submission to Outerzone.

Quote: "A slow, docile flier is this sailplane/motorglider from Czechoslovakia, named after a figure from an old European children's story. Makes an excellent choice for a beginner's first airplane. Fujavak, by Pavel Bosak.

I am a keen model builder and I take part in M3 pattern plane competition. At the beginning I was really enthusiastic about everything but soon I got tired of routine training, which seemed to be endless. I depended on concrete landing sites which are too far from my home. In summer I had to do a decision between bathing in a river or being baked by the sun on the hot concrete landing site. That is why I felt a need to build a model according to these criterias:

1) handlaunch.
2) easy transport; small room needed.
3) slow flight and landing speed.
4) easy starting up engine.
5) a chance of making flight longer by thermal soaring.
6) a stable model, easy to control.

According to these points Fujavak was built. It can be taken to pieces to a nice-looking package. Because a diesel engine is used, only a small bottle of fuel is necessary for flying. Plastic propeller is almost undestroyable. The model flies quietly, slowly, and is easily controlled. It is also easy to change it into a soaring glider.

My first version was controlled by rudder only. With full fuel tank it went up to 1,000 feet and from there it glided about 10 minutes. I flew it near a bathing pool and it was a big success. It was controlled by anybody with hands, from older gentlemen to women and girls. It was really fine but I was not fully satisfied. I wanted to fly before the eyes of an audience. That is why I built in a bigger fuel tank and to the engine I mounted an R/C carburretor. Then the flying was fantastic and the model with little throttle flew just about 15 feet above the ground which was admired by children and dogs especially.

The last version of Fujavak has also elevator control. Thus equipped, Fujavak can also loop, and landing is also nicer. But for Sunday flying this arrangement is not necessary. I personally prefer two-channel R/C gear with rudder and throttle control. I also built a removable undercarriage for nice takeoffs.

To the model belongs also the second half of nose, which, after the engine has been removed and the whole model rebalanced, is screwed to the fuselage and thus we get a nice training glider, easy to take off by tow-hooks, and with a landing skid.

I realized in Fujavak everything I wanted, and it was also built in a few versions by members of our club.

Building: Personally I begin with wings. Cut balsa and plywood ribs, both 1/8 inch. Their shape and number are on the plan. For coupling both halves of wing we use 3/16 steel wire, ten inches long. On it we shall wind tubes of tissue glued with varnish. Beware of sticking tubes on wires! Tubes must easily slide on wire with minimum clearance. With the help of the tubes we shall join three plywood ribs and, according to plan, we shall build the wing frame..."

Update 2/4/2024: Replaced this plan with a clearer copy, now at 600 dpi, thanks to MB2020.

Direct submission to Outerzone.

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