Bronco (oz11176)

 

Bronco (oz11176) by Jim Labarge from American Aircraft Modeler 1972 - plan thumbnail

About this Plan

Bronco. Control line scale twin, for Carrier class. Scale is 1/12.

Quote: "Airborne equivalent of the Jeep makes fine Carrier or Scale model, with twin 19's or 29'2. Lands on deck easily without a hook. Bronco, by Jim Labarge.

The OV-10A Bronco was designed by North American Rockwell to replace the aging, unarmed Cessna Bird Dogs used by the Forward Air Controllers in Southeast Asia. Former President Johnson called this aircraft 'the airborne equivalent of the jeep.'

The powerful Bronco has certainly lived up to its nickname. In 1966 Air Progress ran a cover story on the OV-10A and included some drawings. 1 normally look for unusual airplanes; here was one. Not being sure what kind of model it would make, I built up an all-sheet 049 version. Surprisingly, it flew well. A number of these 049 Broncos were tried out with built-up wings, booms and the like. Satisfied I had a good model, I proposed the little bird as an article for AAM, however, it was suggested that I try a bigger built-up version for Carrier and/or Scale. After much head scratching and midnight oil burning, the prototype appeared at the flying field. While the design was being worked out, Frank Ehling, the technical director for AMA, gave permission to fly the Bronco in Carrier with or without the tailhook. Now we had a model to stop the show in Carrier. And stop the show it does.

Just because the OV-10A has two engines, don't panic and run away. Though there haven't been any twin engines in Carrier since the early '60s, that doesn't mean twins won't work: Properly set up a twin can be a real asset. How many times have you seen a single-engine Carrier model shut down and crash like a rock? That second engine will prevent an embarrassing dunking. If you read the fine print in Section 20.10 in the AMA rule book under Navy Carrier, you will find an extra five points just waiting to be given to the owner of a Bronco. Some Carrier models nose over and lose points or damage airframes. Being a tricycle-geared airplane, the OV has never nosed over, and I save on props. The extra engine is not a problem if you know your engines. I have normally been airborne in 30 seconds.

The aircraft depicted in this model is the Navy-Marine version. It can fly Class I or II just by changing the 19s for 29s (scale is 1 in = 1 ft). Although the canopy is sheeted, the model is close enough to scale to win the the Scale event. The OV won third at the 1971 Air-Zona Invitational.

Before you start building, decide whether you want to fly Carrier or Scale. If you have no intentions of flying Scale with the Bronco, there are a number of things that can improve performance. First get the hottest engines available and install slide valve exhaust and fuel throttling pressure. Replace the clunk type tank with home-made brass tanks and replace the scale wheels with thin speed wheels. Extra details such as machine guns, wings walks, pitot tubes, rivet details and the scale finish can be sacrificed to cut weight. You may want to cut out the centers of the formers but I feel you will cut the life of the model. I am sure there are more ideas, but these are a start.

If you want full scale points for Carrier landings, do the following while the model is being built: install a set of Rocket City wheel brakes to the main gear wheels, and actuate the brakes by running a nylon line up to the throttle transfer crank. Since the brakes must stay clean to work, mount the tank overflow tube away from the brakes. A set of Tatone-type manifolds will keep gunk off the wheels.

If you only want to fly Scale with the OV-1OA, here are some modifications. Add spinners to the engines, route engine exhaust to scale exhaust ports, make up shock- absorbing landing gears, and make the flaps retractable. By mounting the Nyrod in one of the booms and replacing the sheeted canopy with a .030 in plexiglass canopy, the scale effect increases. Add a detailed interior and dropable stores, and the Bronco will take on any scale airplane. More information on the OV-10A Bronco can be obtained from North American Rockwell in Columbus, Ohio, and Garrett AiResearch in Phoenix, Arizona. I have found both companies most helpful.

Construction: The model should be built in five sections and then assembled into one. Since weight can hurt performance (especially in Class I), keep everything as light as possible. The model is big compared to most carriers. Follow the plans carefully. Some new ideas are incorporated in the design.

Cut out all eight pieces of the tail section from 1/4 x 6 inch Sig contest balsa. Glue dorsal fin to main fin and fin to stabilizer. Leave rudders off until final assembly. Hinge the elevator with poly-propylene hinges - three will do. Mount a fairly long control horn on the elevator to minimize movement. Check alignment carefully, and set aside to dry. Next cut out the formers for the booms..."

Bronco, American Aircraft Modeler, October 1972.

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

Bronco (oz11176) by Jim Labarge from American Aircraft Modeler 1972 - model pic

Datafile:
  • (oz11176)
    Bronco
    by Jim Labarge
    from American Aircraft Modeler
    October 1972 
    40in span
    Scale IC C/L Multi Military Bomber
    clean :)
    all formers complete :)
    got article :)
  • Submitted: 16/05/2019
    Filesize: 901KB
    Format: • PDFbitmap
    Credit*: Circlip, RFJ

ScaleType:
  • North_American_Rockwell_OV-10_Bronco | help
    see Wikipedia | search Outerzone


    ScaleType: This (oz11176) 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.


    Notes:
    ScaleType is formed from the last part of the Wikipedia page address, which here is https://en.wikipedia.org/wiki/North_American_Rockwell_OV-10_Bronco
    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.

Bronco (oz11176) by Jim Labarge from American Aircraft Modeler 1972 - pic 003.jpg
003.jpg
Bronco (oz11176) by Jim Labarge from American Aircraft Modeler 1972 - pic 004.jpg
004.jpg
Bronco (oz11176) by Jim Labarge from American Aircraft Modeler 1972 - pic 005.jpg
005.jpg

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, 2011-2022.

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.