Same procedure as for the wings (built-up). Each 1/2 stab has its
own C-4021 servo mounted right on the stab, which facilitates the disassembling by simply unplugging the electronics. The same finish was used as on the wing. Each 1/2 stab weighs 170g finished. The stabs are mounted on the airplane with 2 carbon rods of 6mm (15g) and nothing moves during flight. A single 5mm Nylon screw crosses the fuselage to tie both stab halves together. The tail wheel might weem to be bit complicated, but because of its choice, helps eliminate a lot of weight. This one is from ZN Line and with a foam tire weighs 40g, compared to other commercial units weighing up to 200g, which should make you think.
Flight Test:
After some minor adjustment, the real problems came, the radio. After trying many different places for the receiver (being within all this carbon, it was like within Faraday cage). The receiver was installed as high as possible, the plane would fly OK straight and level, but as soon as I would fly knife edge, the airlane because uncontrollable. The solution was to separate even further the receiver from all this carbon, so I installed the receiver in the head of the pilot, and I haven't had any problems since. Since the engine is directly mounted on the carbon structure, I had to isolate it since I was still having radio problems. Aerodynamically speaking, the model fly's beatifully. Contrary to what they say about the Sukoi 26, this one fly's the knife edge very well, probably has a lot to do with the large canopy. The airplane fly's very slowly compared to other large competition airplanes. The weight probably has a lot to do with this, but when I removed the cowling, the engine would gain 600 rpm. The fact that there is basically no firewall, with the air going straight though the fuselage, might not be such a good idea. The landing gear (the one from the Cap from ZN Line) full of lightening holes lost 140g on the original 520g.
Conclusion:
After reading this article, some of you will surely say that this type of construction is borderline crazy, but the results obtained, are well worth it. its a new avenue in the construction of high performance aerobatic airplanes where the compromise of weight-solidity-power is more important then ever. All I have done, is copy the principal of the original by adapting the build-up structure to the different elements (engine, radio.....) This type of construction can be applied to any type of high performance airplanes. We could even ask ourselves if this type of construction would be too light, but the advantage woud be to be able to add smokers, airbrakes, extra servos, (Fiber Optic servo extensions) without adding any extra weight that would compromise the well being of the airplane. The flight starts with the construction of the airplane. All of the airplanes can do rolls and loops, but which one can actually do proper torque rolls? Imagine the power to weight ratio that is needed to be able to go down and then back up all in a torque roll position, shure there is the pilot, but without the proper airplane there is nothing.
I hope that this article will give some of you the taste to try new types of construction and continue the evolution of this fantastic hobby.
Written by Olivier Moquereau
Translated by Roger Forgues
