About this Plan
Bonzo. Control line scale model.
Direct submission to Outerzone.
Planfile includes full build instructions.
Update 19/8/2023: Added article, as reprinted in Kapa Kollector #79.
Quote: "Of all the designs to appear in Goodyear and Continental racing, Steve Wittman's Buster and Bonzo have consistently shown their tail skids to the competition. If ever design simplicity has proven its worth performance wise, these airplanes put the QED on the formula.
Bonzo could be called a sister ship to Buster and through the latter can trace its ancestry back to the prewar race days. Steve's success since then certainly has not diminished in the midget field, and was climaxed at the 1952 Air Races by his third win of the Continental Trophy. Wittman announced his retirement from air racing as he proudly took permanent possession of the big mug. So Bonzo becomes a piece of aeronautical history; it represents the tops in prop-driven midget racers.
Bonzo's configuration has set the style for many of its competitors. The high mid-wing with engine fairings flowing smoothly into the wing is probably the most copied feature. Construction follows standard lightplane practice with welded steel tube fuselage, stringers and fabric covering. Tails are steel tube, fabric covered, while wings are wood structure with plywood skin. Cowlings and fairings are formed from sheet aluminum.
One feature used by Wittman is the wire-braced wing, saving much weight in structure at very slight additional drag. The flat plate gear invented by Wittman is of course employed. The working end of the 85 hp Continental turned many an experimental prop, notably the scimitar shape pioneered by Wittman. The 1952 win was made with a metal Sensenich scimitar prop. Canopy design is simplicity itself, using flat sheet rather than a blown bubble. Bonzo has lowest aspect ratio wing of any of the racers, slightly less than 4 to 1, giving a span of 15 ft 4 in. Length is 17 ft 6 in.
Bonzo is an excellent choice for flying scale fans. Its many straight lines lend themselves to easy and quick construction. If the team race boys wanted to fudge a bit and hide the inverted engine with a larger cowling, Bonzo would be a real competitor in the race circle, her size and weight being within all requirements. Although stunting is no longer required for flying scale events, Bonzo is quite capable of all but the most difficult stunts. On the first flight the original model with stunt ribs looped and flew inverted with ease despite an over-rich throttle setting.
The model is built to the old faithful scale, 1-1/4 in = 1 ft, which your author feels is just the right size for .23, .29, .32 powerplants. Model span is 26-1/8 in, length is 31 in, wing area is 197 sq in, and weight is 1-1/2 lbs, extremely light for most flying scale models. Original engine used was O&R .23 swinging a 9/6 Power Prop, but engines up to .32 or 33 could be used for really high speed, If larger engines are used model will balance fairly nose heavy and lead may have to be added to the tail.
Complete construction details are available on the full-size plans."
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
Wittman_DFA | help
see Wikipedia | search Outerzone
search RCLibrary 3views (opens in new window)
ScaleType: This (oz7348) is a scale plan. Where possible we link scale plans to Wikipedia, using a text string called ScaleType.
If we got this right, you now have a couple of direct links (above) to 1. see the Wikipedia page, and 2. search Oz for more plans of this type. If we didn't, then see below.
ScaleType is formed from the last part of the Wikipedia page address, which here is https://en.wikipedia.org/wiki/Wittman_DFA
Wikipedia page addresses may well change over time.
For more obscure types, there currently will be no Wiki page found. We tag these cases as ScaleType = NotFound. These will change over time.
Corrections? Use the correction form to tell us the new/better ScaleType link we should be using. Thanks.
Do you have a photo you'd like to submit for this page? Then email firstname.lastname@example.org
User commentsNo comments yet for this plan. Got something to say about this one?
Add a comment
* 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.
© 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.