Triangle (oz11504)


Triangle (oz11504) by Frank Ehling 1938 - plan thumbnail

About this Plan

Triangle. Free flight power model. Original used Ohlsson 23 engine.

Later featured in a nostalgia article in Dec 1978 MB:

Quote: "OLD TIMER Model of the Month. Triangle, by Frank Ehling. Text by Phil Bernhardt.

Here's an Old Timer that probably even John Pond doesn't know about. It's Frank Ehling's Triangle, designed and built in 1938. Actually, the first Triangle was twice the size of the model presented here. When Ehling's club decided to hold a marathon contest at Cherry Hill, NJ, he built a half-size version (the model presented here) and powered it with an Ohlsson .23. The idea was to put in as many one-minute flights as possible in one hour. All flights were ROG, and if you broke a prop, you were out (that's why the wheel is out in front of the prop). The model turned out to be a good, stable flier so much so that Ehling won, the contest!

The plans for the Triangle were sent to us by Bernard Shulman, who got them directly from Frank Ehling himself. Bernard has been flying a Triangle with a Cox Tee Dee .049 and Ace single-channel pulse radio, and has been having a ball with it. For those who may want to do the same thing, we've included a sketch of the modified rudder on the drawing.

Bernard says the model flies better with the wing moved a 1/2 inch forward of the position shown, and with 3/16 inch of incidence under the LE of the wing. He also used spruce for the wing LE and spar (the original used balsa). Bernard says the Triangle is so odd-looking, his wife thinks it's cute. Well, it's odd-looking, all right nobody will disagree with that - but cute?"

Quote: "1938 Frank Ehling Triangle. Drawn especially for John Pond."

Scan from DBHL, cleanup by theshadow.

ref DBHL-7239.

Direct submission to Outerzone.

Supplementary file notes

Article (Dec 1978 MB).


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

Triangle (oz11504) by Frank Ehling 1938 - model pic

  • (oz11504)
    by Frank Ehling
    48in span
    IC F/F
    all formers complete :)
    got article :)
  • Submitted: 27/08/2019
    Filesize: 297KB
    Format: • PDFbitmap
    Credit*: DBHL, theshadow

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, 2011-2019.

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.