Sun Ray (oz5956)
About this Plan
Sun Ray/ Sunray. RC sport biplane model. 51in span, 700 sq in area, for .61 power and 4 channel RC. Model: pl-591. Designed by Jack Scarbrough. Featured in RCM 3-75.
Quote: "Build this high performance biplane for a rewarding new experience in sport and pattern flying. By Jack Scarbrough.
Designed as a new type of biplane for R/C models, this .60 powered plane has the sleek high speed appearance of the latest of the small full-size racing 'sport biplanes'. But in contrast to the pure racing type, the Sun Ray incorporates superior stalling, stability and control characteristics, comparable to the best design practice in R/C pattern planes. At the same time, the low drag inherent in the wing to fuselage and cockpit configuration is retained.
This is a fast biplane, highly maneuverable and performs all AMA and FAI patterns, is good for open pylon, and makes a great all around sport plane for the Sunday flyer. She's extremely steady and stable in high winds, with easy stall characteristics and slow landing speed. The wide stance landing gear sets up good control in ground maneuvers, landings, and take-offs. One of the most remarkable features of this airplane is its ability to do sustained knife edge flight, and starting from straight level flight, will climb out and complete a 270° knife edge loop! The plane is completely predictable in all flight maneuvers.
Major Construction Features. Both wings are removable, using standard leading edge locating dowels and aft nylon wing hold-down bolts. The cockpit enclosure and platform over the wing are one unit, removable to allow access to the upper wing hold-down bolts. The radio is reached from above, with upper wing removed.
No hatches exist, access to the fuel tank and battery pack compartment being through the upper wing space and forward through a generously cut-out bulkhead. 1/16 in plywood doublers inside the balsa fuselage sides run 24 in back from the firewall past the wings. These doublers are necessary, especially with 2 wing saddle cut-outs.
Landing gear wire has a minimum of exposed length, utilizing part of the inverted gull section of the lower wing, both for strength and air drag reduction. The lower wing is built on a full depth 1/4 in thick plywood continuous spar, to assure maximum strength through the angled joints and center section.
Most basic building features are normal, with easy construction throughout..."
Update 19/10/2016: article pages, text & pics added, thanks to RFJ.
Supplementary file notes
Article pages, text & pics.
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
Do you have a photo you'd like to submit for this page? Then email email@example.com
User commentsPlease, add to this model: Sun Ray - by Jack Scarbrough from RCMplans - 1975 - 51in span - IC R/C Biplane. My model is a 112% scale from the original (wing span: 57 in, engine: OS AX65) [model photo & more pics 007]. Thank you!
LucD - 29/01/2019
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, 2011-2019.
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.