fledermaus

Starting to work on some CAD plans to build a large Bellanca Aircruiser - 130 inch span, to be powered by a DLE 55. This is the first really large plane I have considered building.

Question about sizing the structural frame members. The fuselage is a typical box truss design. If I use spruce square stock for the truss members, will 0.25 inch be strong enough for this size of airframe, or would I be better to base the design on 0.375 inch square stock?

iron eagel

I have one in that size that uses 3/8 balsa for the frame it is powered by a zenoa G38. Mine is actually the "airbus" version but close enough to call it the same plane I think the only difference is the aircruiser had a water cooled engine that wasn't as powerful as the air cooled version the airbus used. I think they were both referred to as the flying W...

fledermaus

Thanks for the input. I am using the same set of drawings as the basis for my plans. They come from the local historical aviation society, and the Western Canada Aviation Museum is restoring CF-AWR, "The Eldorado Radium Silver Express". I've had a lot of opportunity to examine the airframe over the last several years as they have worked on it.

The Aircruiser still had the radial air-cooled engine - as you can see in your drawing of CF-BTW it had a Pratt&Whitney Hornet R-1690-SIEG supercharged engine (750 HP), while the Airbus used the Wright Cyclone R-1820E (575 HP). CF-AWR was fitted with a Wright Cyclone R-1820 F-32 that delivered 760 HP at 2100 rpm.

iron eagel

With those drawings and using cad you will be able to generate a real nice set of plans to build from, your going to have a real leg up building it.

Wow, thanks for the information all I knew is the power plants were different I wasn't sure how. I'd love to see that plane close up.

One note on construction 1/6 ply gussets were used for all of the truss joints and 1/2 solid balsa for nose construction with a plywood firewall. Weight of this 130 inch version is 23lbs (far too heavy) flies what I would call very scale...

I always though it was interesting to note that this airframe was Lindberg's first choice for his transatlantic flight, a very interesting design for the time, not to mention that "Corsair look" from the front.