Reliant oz10114


Reliant - plan thumbnail image

Reliant - completed model photo

Submitted to Outerzone: 18/05/2018
Outerzone planID: oz10114 | Filesize: 680KB | Format: • PDFbitmap | Credit*: Circlip, RFJ


About this Plan

Reliant. Rubber competition model.

Quote: "The Reliant. Super consistent automated Wakefield for winning in FAI meets. By Arik Donde.

The impossible dream, free flight style: Arrive at the contest field, assemble your well-tested ship, no test flights, no last minute adjustment - just fly and walk home with all the loot. In short, reliable delivery.

This was my dream (and still is) when in the summer of '69 I decided to build the next 'World Champion Wakefield.' Have you ever heard of an FAI Flier who aspires lower? It was quite a pretentious undertaking, considering that about a thousand other modelers the world over had made a similar decision.

To realize these aspirations, two basic tasks had to be accomplished. First, the model would have to be designed aerodynamically with 'The State of the Art.' Second, it must be mechanically sound, which means: trouble free, consistency of adjustments, rigid and durable - in this order.

All this appeared at first to be an insurmountable feat to one whose total experience in the rubber events amounted to two Coupes and one Unlimited rubber. Fortunately, in free-flight aeromodeling there is friendship and a willingness to share knowledge and experience, thus one can accumulate information from magazines, modeling publications, and personal correspondence. Recognizing this asset, a thorough study of the literature revealed the names of some of Wakefield's highest priests. Their efforts in theoretical analysis of what makes the Wakefield 'tick,' as well as their success in incorporating this in practical design and competition, contributed a quantum jump in the effort to extract that elusive extra feet of altitude from every inch - ounce of energy stored in a wound rubber motor.

George Xenakis' mathematical modeling of the model flight trajectory as affected by time history of the rub-ber energy dissipation characteristics, has led to the conclusion to vary the model trimming linearly with rubber torque output. Similarly, Christian Schwartzbach's analysis of propeller blade-element dictated a non-helical propeller. I am endlessly indebted to both for sharing their knowledge with us.

Fully convinced, and having access to computer timesharing, I followed Schwartzbach's propeller blade analysis with a computer program whose output was the blade's length, chord width, corrected pitch angle, element thickness and carving layout coordinates for every pitch-diameter combination desired. Next, a fairly conservative (from stability considerations) wing and stabilizer planforms were designed employing Thomas Koster's wing airfoil and the classical B-6405-b stab section. Later, experience added a thread turbulator at 5% wing-chord while maintaining the very sharp leading edge... "

Reliant, American Aircraft Modeler, May 1973.

Direct submission to Outerzone.

Supplementary files

Article pages, thanks to RFJ.


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oz10114 datafile

by Arik Donde
from American Aircraft Modeler
May 1973 
58in span
Tags: Rubber F/F
all formers complete :)
got article :)



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