Skylark (oz381)

About this Plan

Skylark. Free flight sport power model, with 31in wingspan. Plan shows a Cub .049 engine.

Quote: "How simple, can you design a half-A free flight and still have good performance and eye appeal? That was the idea behind Skylark. Perhaps we were influenced by the prefabrication trend of control-line kits. Could the fact that we had recently purchased some very nice, light quarter-grained 4in wide sheets have had anything to do with it? At any rate we decided to forget about the traditional stringer-cement-tissue type of construction and explore the possibilities of sheet balsa.
Excessive weight would be the result of all-sheet covering, so the Sky-Sail tissue wing construction and stabilizer are a compromise. But both are much more quickly made than if the usual construction were used. Don't take our word for it, try building the Skylark yoursell. Select four sheets of light, quarter-grained 1/16 x 4 x 36in sheets at your local hobby shop. Enlarge the plans using the scale reproduced on the border of the drawing.
Both the wing and stabilizer are constructed in the same manner: the outlines are cut from sheet which takes the place of the customary leading edge, tip, and trailing edge. Note that the stabilizer outline comes out of the piece cut from the inside of the wing panels. If the area of the stabilizer looks small in proportion to the wing area when compared to most free flights, we have allowed for this in the design by providing an extra long tail moment arm (longer fuselage) and used a high-lift airfoil to make the small stabilizer more effective. Most free flights carry a lot more stabilizer area than is necessary for proper lortgitudinal stability. Twenty-five to thirty percent of the wing area is ample in most designs providing an average length moment arm is used..."

Update 23/11/2017: Replaced this plan with a clearer copy, thanks to dfritzke.

Direct submission to Outerzone.

Supplementary file notes

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