Sundowner F-4B (oz9586)

 

Sundowner F-4B (oz9586) by Bob Violett 1974 - plan thumbnail

About this Plan

Sundowner F-4B. Radio control sport model, using ducted I/C fan.

Quote: "It's been a long time coming! There have been many noble efforts along the way toward the successful development of true ducted fan flight, but these have always produced something less than maximum efficiency. Having probably already glanced at the photos that ac-company this article, I'm sure that your scepticism is equal to what mine was about six months ago, when AAM's Editor asked that I consider building an airplane around the new JJ Scozzi Turb-Ax 1. Let it suffice to say that, as a modeler tuned to the high performance spectra of RC, it took only one demonstration of the thrust of this unit to really turn me on to the project.

A reasonable question is why a 40 cu, in. engine was chosen, instead of a 60? The answer lies in horsepower and available rpm. The 5in fan must turn faster than an 11in prop, to gain comparable efficiency. At these higher rpm, the newer K&B 40s, Supertigres and HPs (rear rotor) develop more horse-power, on the same fuel, than do most of the pattern 60s. Furthermore, by using a 40, the overall mass of the power unit is held to an acceptable level, so that it adapts well to the airframe sizes to which we are accustomed.

The operation of the unit is uncomplicated. Starting is achieved by a prime in the exhaust and one snappy flip against compression. A belt starter, as utilized by the boat and helicopter folks, can be used by the less adventurous. Throttle is achieved by the same method employed on control line Navy Carrier models, via fuel metering and a slide exhaust baffle. The Turb-Ax instructions detail this throttle setup.

The vibration level of the fan is lower in amplitude, but higher in frequency, than prop-driven engines. A nice secondary benefit of jet power is that, if you are thinking retracts, you'll never wear out another nose unit.

It is believed that the most enthusiasm for this new concept in power sources will emanate from stand-off scale and pattern (although the appeal to the average sport flier and would-be designer is very strong). With this in mind, the Sundowner evolved from a series of three aircraft, which were built and flown with the Turb-Ax unit. The first two were something less than fantastic; but then, I didn't win anything with my first pylon racer either. The McDonnell-Douglas Phantom, after which the Sundowner is modeled, is the mainstay of the US Navy and USAF fighter wings, as well as many allied air arms. As a subject for this pro-ject, it not only offers this universal appeal, but the design has everything in the right place for an aerodynamically sound model. The proportions are generous enough..."

Sundowner, American Aircraft Modeler, July 1974.

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

Sundowner F-4B (oz9586) by Bob Violett 1974 - model pic

Datafile:
  • (oz9586)
    Sundowner F-4B
    by Bob Violett
    from American Aircraft Modeler
    July 1974 
    59in span
    IC R/C LowWing
    clean :)
    all formers complete :)
    got article :)
  • Submitted: 15/12/2017
    Filesize: 727KB
    Format: • PDFbitmap
    Credit*: Circlip, RFJ

Sundowner F-4B (oz9586) by Bob Violett 1974 - pic 003.jpg
003.jpg
Sundowner F-4B (oz9586) by Bob Violett 1974 - pic 004.jpg
004.jpg
Sundowner F-4B (oz9586) by Bob Violett 1974 - 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.