Sun Ray (oz5956)


Sun Ray - plan thumbnail image

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.


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User comments

Please, 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
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