Bi-Playne (oz6901)


Bi-Playne (oz6901) by George Woolls 1960 - plan thumbnail

About this Plan

Bi-Playne. Free flight sport model biplane.

Quote: "'Bi-Playne' is a scaled up version of a little 10 inch span all balsa rubber powered bipe that, despite being built some 3 years ago, still provides a lot of fun. Powered with a .049 engine, this all sheet sport design has a contest-like performance In keeping with its racy lines, but a Cox Pee-Wee should provide ample power for steady flying in confined areas.

The all sheet construction and extensive use of rubber band fixings adds up to an extremely rugged model which will take the hardest knocks with a minimum of damage. Repairs are easy to make when necessary due to the generous sheet sizes called for. Thorough test flying of the prototype has borne out the above statement, for until the original undercambered 1/16 sheet stabilizer was replaced by the flat bottomed section shown on the plan, flights were somewhat erratic, due to the fact that the stabilizer developed too much lift under full engine power. Several full power dives into the ground resulted in only minor and quickly repaired damage.

We would hasten to say that this bug has been ironed out in the 'production version' presented here. A small snag remaining in our model, a tendency to nose over on landing on anything but surfaces of putting green smoothness, would be remedied by advancing the wheel position slightly and this modification has been incorporated on the accompanying full size plan.

So, with all the development that we have carried out ensuring that you have a well tested and proven airplane to provide you with lost of fun, why not make a start on the construction.

Fuselage: This, less the top decking, is built upside down on the building board. The 1/16 sheet backbone is marked with the former positions (ball point pens are ideal for marking balsa) and the engine bearers firmly cemented in position. It is convenient to drill these to suit your engine at this time.

Temporarily pin the backbone to the building board and add the 1/16 sheet lower formers, cutting the forward ones to fit snugly around the engine bearers. Check that all these formers are at right angles to the backbone. Now add the 1/8 sheet underfin complete with .048 dia piano wire tail skid and then cement the 1/16 sheet fuselage sides in position, ensuring plenty of cement around the engine bearers.

When dry, remove the pins holding the backbone to the building board and using a sandpaper block sand off any formers that may project beyond the sides. Any formers that are below should be built up level with scrap sheet... "

Supplementary file notes



Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction

Bi-Playne (oz6901) by George Woolls 1960 - model pic


Do you have a photo you'd like to submit for this page? Then email

User comments

No comments yet for this plan. Got something to say about this one?
Add a comment



Download File(s):


* Credit field

The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.


This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.


Terms of Use

© Outerzone, 2011-2024.

All content is free to download for personal use.

For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.

Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.