Airacobra (oz10380)

 

Airacobra (oz10380) by Robin Woodhead from Aeromodeller 1973 - plan thumbnail

About this Plan

Airacobra. Semi scale stunter for control line.

Quote: "A 60 inch span semi-scale control line stunter featuring a detachable wing, for use with 0.35 - 0.40 cu in motors. Airacobra, designed by Robin Woodhead.

HAVING BEEN an aeromodeller for many years, I have always held the belief that models should at least look something like the real thing, but when you study most stunt models, what do you see? A wing out of proportion to the fuselage and a model that bears little resemblance to an aeroplane. Possibly this is a direct result of the exclusion of design, detail and finish points from the FAT schedule, but whatever the reason, this should not be an excuse for not trying to design and build better models.

Deciding which aircraft would be most suitable as a basis for a stunter was not easy, as it had to fit several requirements ie: low wing, monoplane, single engine and most important of all, it had to be one that nobody else had done! Eventually the choice lay between the Martin Baker MB5 and the Bell Airacobra: I chose the Airacobra because it has a slightly longer nose movement.

The removable wing was decided upon as the resulting model was just too big to fit in my car in one piece! This posed a new problem: how to make a quick, simple linkage between bellcrank and elevator? I personally don't think the method I evolved can be bettered as it is simple, cheap, positive: free moving and easy to assemble on the flying field. There are two other benefits with this set up, namely that it is simple to adjust the ratio of movement between the flaps and elevator, and secondly trim between flaps and elevator is possible by fitting an adjustable link to the flap horn. The only disadvantage seems to be a slight increase in weight.

For those of you who have not used nylon engine mounts, I can strongly recommend that you give them a try. They are quite expensive but their convenience far outweighs they cost; for example it's far easier to replace an engine mount than strip the model to replace broken bearers, while it is also far handier having a common system of mounting engines- which allows switching of engines between models, instead of peppering the engine bearers full of holes!

In building models, I have used a number of techniques, but have found the easiest is to use a jig. This does not have to be very complex, in fact the simpler the better (see sketches on plan). I also cut out as many pieces of the model as possible before starting to build as this saves a lot of time later.

Construction is started with the wing. Make the trailing edge assembly by bonding together two lengths of 1/4 in sq balsa, 1/4 in beech centre section and the tip forms WT2; then place in jig. Next make the leading edge by bonding two lengths of 1/4 in sq to the 5/16 in beech centre section, and again place in jig. Note: both beech centre sections are drilled before assembly..."

Airacobra, Aeromodeller, August 1973.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

Corrections?

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

Airacobra (oz10380) by Robin Woodhead from Aeromodeller 1973 - model pic

Datafile:
  • (oz10380)
    Airacobra
    by Robin Woodhead
    from Aeromodeller
    August 1973 
    61in span
    IC C/L
    all formers complete :)
    got article :)
  • Submitted: 18/08/2018
    Filesize: 871KB
    Format: • PDFbitmap
    Credit*: Circlip, RFJ

Do you have a photo you'd like to submit for this page? Then email admin@outerzone.co.uk

User comments

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

 

 
 

Download File(s):
 

Notes

* 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.

Scaling

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, 2011-2019.

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.