Wrinkly Bottom Flyer (oz11673)

About this Plan

Wrinkly Bottom Flyer. Radio control sport model, for .25 engines.

Quote: "Stable and forgiving - ideal qualities for any sport model. Wrinkly Bottom Flyer, by Ron Bishop.

When Ron Bishop lash did the washing up he didn't just come away with clean Marigolds - oh no! Give a modeller a dirty saucepan and he'll turn it info an aeroplane for sure. Writing from the sun drenched beaches or Alicante, Ron explains the true inspiration behind Wrinkly Bottom Flyer and guides us through the construction.

After an enjoyable flying session one Sunday last September, the Wrinkly Bottom Flyer was conceived in an attempt to get certain of our club members away from the idea that trainers and sports planes should be able to withstand accidents by building them hefty. Many seemed to believe that using large chunks of balsa, reinforcing with plywood and glass fibre and mounting to an undercarriage more suited to a Boeing 747 was the way to go, providing that you fitted the largest engine it was possible to shoehorn in to get the whole lot off the ground.

Having cut my teeth on free flight models in the 1940's and 50's I tend to take the view that a plane is likely to survive a lot longer if the weight is kept down thereby keeping the flying speed down and making 'arrivals' a much less traumatic affair. With this in mind I sorted through the materials I had in stock (my nearest model shop is 60 miles away) and found sufficient material for a suitable size model for a new OS 25 which had been recently acquired and run-in on the test bench. I also had in stock a very light tin saucepan which, with cowlings in mind, I had purchased some weeks earlier at the local market.

Bottom building: So, the size of the front former was decided for me and from there on it was just a case of 'keep it simple - keep it light'.
If it looks right it will probably fly right! Starting with the fuselage, construction follows the traditional method and should be well within the capabilities of anyone who has had some experience of building model aircraft.

Using 1/4 in sq medium balsa, start by building two identical fuselage side frames directly over the plan. For the benefit of anyone putting their faith in my design and building the Wrinkly Bottom Flyer, there is the obligatory reminder that when gluing the two ply doublers to the fuselage side frames you do need to ensure that you have one left side and one right side. I used 5 minute epoxy for this step - strong and quick! From here on, it's plain sailing. When set, stand the fuselage side frames vertically and form the traditional 'box' fuselage..."

Wrinkly Bottom Flyer, RCM&E, November 1996.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

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