Frog MkIV Interceptor Fighter (oz4920)


Frog MkIV Interceptor Fighter (oz4920) 1932 - plan thumbnail

About this Plan

Frog Interceptor (Wilmot Frog IV). Rubber powered sport model. This drawing and short article are available in the online Flight Magazine PDF archive, detailing the model as sold in 1932.

Quote: "As will be seen from our illustrations, the 'Frog' is extraordinarily realistic - the slightly larger aircrew being, perhaps, the only item not in true proportion to a full-size machine. Appearance however is not the only feature of the Frog for it is an excellent flyer, ROG or hand-launched, indoors or outdoors. Constructionally, this little model (it is just under 12in span) is a masterpiece, both as regards workmanship and ingenuity in the working of the material used - mainly a very thin light metal alloy and paper, the fuselage being pressed out from the metal and the double surfaced wings being of specially doped paper with metal ribs. The elastic motor, neatly housed within the fuselage, drives the tractor airscrew through a 3.4:1 gearing - a somewhat unusual feature in so small a model. As sold, the model is housed in a string box, embodied in the end of which is a geared winder, which engages with the airscrew as the model lies in its box so that winding up the motor..."

Quote: "This is the FROG Interceptor Mk IV, supplied as a ready to fly model complete with a winder for the rubber motor built into the box it came in. There were several marks of this famous model, starting in the 1930's and continuing after the war. The fuselage was thin aluminium and the wings folded card with spars. Several scaled up versions of this classic design have been produced for radio and electric power in the last few years, one notable one by Chris Golds. It makes a very good electric R/C model."

Note this is not a detailed plan showing parts and formers, this is just a general layout drawing. The model was sold RTF so there never was a plan. I am including this (not very detailed) drawing in the Outerzone listing because the Interceptor was such an iconic design, and in the hope that other more detailed drawings may surface.


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

Frog MkIV Interceptor Fighter (oz4920) 1932 - model pic


Frog MkIV Interceptor Fighter (oz4920) 1932 - pic 003.jpg
Frog MkIV Interceptor Fighter (oz4920) 1932 - pic 004.jpg
Frog MkIV Interceptor Fighter (oz4920) 1932 - pic 005.jpg
Frog MkIV Interceptor Fighter (oz4920) 1932 - pic 006.jpg
Frog MkIV Interceptor Fighter (oz4920) 1932 - pic 007.jpg
Frog MkIV Interceptor Fighter (oz4920) 1932 - pic 008.jpg
Frog MkIV Interceptor Fighter (oz4920) 1932 - pic 009.jpg

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

User comments

Hi friends, I found your site while seeking info on my late father's rubber powered model airplane. I decided to send you some pics [morepics 5-7] because I find it unusual that Frog would adapt production to export countries and then apply the local air force markings. Owing to the code number and my father's age I believe the airplane dates to 1929. The puppet pilot figure does not belong to the plane. I expect it may serve as information. Best Regards
Eddy, Argentina - 24/09/2021
Hi here, friends! Thanks for adding the pics! Wealth of information in your Web, keep the good work up! Best regards!
Eddy - 24/09/2021
Thank you for providing this diagram of the Frog Fighter. It might not be 'proper' plan, but it provided an ideal template for building a wallpaper-foam version for our club's 'indoor foamie challenge' event [pics 008, 009]. To make the foam version easier to build, I expanded the size by 12% and enlarged the fuselage cross-section slightly to accommodate the formers and rubber motor.
After much test-flying and trimming it eventually performed well, although it was a little too fast for our village hall venue. Missing the ceiling, walls, and onlookers by millimetres, it won a prize for the 'scariest flight'.
Simon Burch - 19/02/2023
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.