Valkyrie (oz18)

About this Plan

Valkyrie. Free flight power model.

The original 10 ft Carl Goldberg Valkyrie (oz6156) was from 1938 Air Trails. This one is much later, redrawn by Al Patterson for MB in 1979. This is a scaled down 38-1/2in wingspan version.

Update 27/09/2014: Replaced this plan with a copy at correct full-scale, thanks to HarryD.

Quote: "Old Timer Model of the Month. Valkyrie. Designed by Carl Goldberg/Rudy Calvo. Drawn by Al Patterson, Text by Rudy Calvo.

The Valkyrie, designed by Carl Goldberg, appeared in Air Trails in two parts, issues September and October 1938. The theme: A high-performance gas model combining light weight and streamlining. No doubt the design was influenced by Carl's background related to indoor models. Carl, retained by the Comet Model Company, continued the competitive spirit and designed such great models as the Zipper (oz387), Sailplane (oz1058), Interceptor (oz7608), Mercury, and Clipper (oz7380). However, the Valkyrie (oz713) reduced in size and modified for rubber, produced by the Scientific Model Company, has remained in my thoughts since my youth. What a beautiful design!

About 8 years ago I was made aware of the SCAMPS Old Timer club through Model Builder. This was an article describing Cal Aero information. Anyhow, Bob Oslan was kind enough to inform me of the Old Timer movement.

Jimmy Dean had the Air Trails issues, and that's how it all started. I have built the Valkyrie in an .020 replica version, the subject of this article, a half-size version (60-inch span) with an Arden .199, and a full-size version, R/C, OS.40 (shown in Model Builder, April 1979 issue, at the Pasadena IMS Show). If a little extra work doesn't offend you, here's a plane you can have a lot of fun with.

My plane weighed in at 6 oz, it's a little large for .020 application, but I felt the clean aerodynamics design, minimum parasite drag, and high-lift wing would overcome the higher performance of other designs, or at least be somewhat competitive. But enough of the historical background. Let's get on with the construction.

FUSELAGE: The fuselage is built on a 1/8 sq crutch with 1/8 x 1/16 spacers behind each bulkhead. This method speeds construction and is similar to the concept of Gene Wallock and others. The bulkheads are solid 1/16 sheet. You may elect to hollow the formers for weight consideration. The bulkheads are 1/16 of an inch less than the finished skin, with 1/16-inch notches to receive hard 1/16 x 1/8 longerons. The landing gear bulkhead is 1/16 plywood and the assembly is set in place on the crutch.

The firewall is 1/8 plywood with blind nuts and is set in place complete on the crutch. The pylon is laminated sheet as noted on the plan. Wing platform is 1/16 sheet. The fuel shutoff timer is set on the right side next to the firewall, just below the 1/8 sq crutch.

WING: The wing ribs are made from a 1/16 plywood template, full size, as noted in the profile view, The method is to rotate the template to ihe chord length at each station. The rest should be like typical wing construction.

TAIL SURFACES The horizontal stabilizer uses a full-depth spar to minimize warpage. The rest is of conventional construction.

FINISHING THE MODEL The fuselage is lightweight silk, ap-plied wet. The wing and tail surfaces are Japanese tissue. Pre-dope the surfaces and apply the covering with acetone. I used 5 coats of 50-50 nitrate dope. The final 2 light coats are 253-00 gloss Fullerplast (sprayed). This is an industrial coating manufactured by Fuller O'Brien. It requires 283-00 Fullerplast catalyst and then 50-50 mixing with fuller 181-00 thinner (fast) for spraying application.

FLYING THE MODEL The model flew right oft the board! Mine required a little right thrust and up thrust with a sandpaper shim. Right rudder was also required. Your model may not require these adjustments. Tilt in the stab may be required for a right glide pattern. My plane flies right-right. The power pattern, considering the size, is a reasonably fast, tight right spiral, then watch the glide! This has been a most enjoyable experience and still is! And that's what it's all about."

Supplementary file notes

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