Boxy Bipe (oz14481)


Boxy Bipe (oz14481) by Bill Hannan 1985 - plan thumbnail

About this Plan

Boxy Bipe. Simple rubber model for indoor flying.

Quote: "Hi Mary, Attached is a plan recently uploaded by Zeke to Hip Pocket Aeronautics of the Bill Hannan designed Boxy Bipe. I also included a few photos of the one I built for indoor flying. Thanks for everything!"

Note this plan was (first?) published in 'Models and Musings' by Bill Hannan, 1985, along with an article and some pics, see for more details and a free download of the complete book.

Quote: "HERE'S A LITTLE two-winger which is both easy and inexpensive to construct. The fuselage, propeller assembly and landing gear are from a North Pacific 'Sleek Streek,' and a few items from your scrap box should complete the project.

The model is somewhat unusual in that it employs absolutely no dihedral. Instead, lateral stability is assured by the vertical curtain surfaces separating the wings. A glider, by Frank Scott/Jiri Kalina, featur-ing this system appeared in the February Model Aviation (1976).

But the idea originated early in aviation history, having been advocated by Australian Lawrence Hargrave, inventor of the box kite, during 1893. Credit is also due FW Lanchester, of England, who flew model gliders with vertical stabilizing vanes during the early 1900's. The first constructor to apply the concept to full-size aircraft appears to have been Gabriel Voisin, during 1905. Santos-Dumont, who also employed wing curtains (six of 'em!), hedged his bets by using dihedral too. Other early experimenters who tried the idea include Louis Bleriot and Henri Farman.

Interestingly, many pioneer model 'aeroplanes' flew without dihedral or vertical curtains either, but the majority seem to have been gliders or contra-rotating propeller-driven twin-pushers, which are not subject to the destabilizing effects of a single propeller. Then, too, a number of successful free-flight scale models were flown without dihedral, but most cheated a bit, using wing-tip washout or pendulum controls.

A few years ago, Walt Mooney published a series of models which revived the vertical curtain theory, but in a new form, using oversize profile pilot caricatures for lateral stabilization.

Dihedral joints have always been a source of difficulty to beginning builders, and are often failure-prone in case of a crash. So here's your chance to try this well-proven, but seldom seen alternative, and have some fun in the process!

First, purchase a North Pacific Sleek Streek ready-to-fly model. You may as well fly the Streek for a while, as the parts needed for this model are not apt to be damaged in the process.

Other materials required include: Several 1/16 sq balsa strips, lightweight colored tissue paper, a small section of 1/16 sheet balsa (Note: it would be possible to laminate 1/16 sq strips for the purpose), your choice of glue, plastic wrap.

Tools suggested include: Single-edge razor blade, sharp modeling knife with pointed blade, scissors, common pins..."

Note this design was also later kitted by SIG as the 'Uncle Sam Biplane'. Then discontinued.

Supplementary file notes

Article, thanks to Mary, from RCL.


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Boxy Bipe (oz14481) by Bill Hannan 1985 - model pic


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Boxy Bipe (oz14481) by Bill Hannan 1985 - pic 004.jpg
Boxy Bipe (oz14481) by Bill Hannan 1985 - pic 005.jpg

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