Druine Turbi (oz16025)

About this Plan

Druine Turbi. Radio control scale model. Wingspan 32 in, for Thunder Tiger GP07 or similar engine and 4 function RC.

Direct submission to Outerzone.

Update 15/5/2025: Added article, thanks to RFJ.

Quote: "This little 'mini' model was designed as a sequel to my previous 'Mini Turbulent', in fact the Turbi uses the same wing and tail group. The reason being I broke the Turbulent fuselage: I was trying an idea I had thought of for a long time - a bigger version. Unfortunately for me it was not particularly successful and it crashed, hence the spare wing and tail.

So back to the Turbi, and this seemed like a good idea! The D-5 Turbi and D-31 Turbulent are virtually the same proportionally, only the Turbi is a larger scale if you see what I mean. Roger Druine could probably have just taken the Turbulent and multiplied it by a factor of approximately 1.4 to arrive at the Turbi's span of 28 ft 9 in. I suspect actually there was a lot more thought put into designing the bigger aeroplane than that, but however the proportions are so similar that the wing and tail I had spare just had to be used.

The full-size (Rollason) Druine D-5 Turbi was designed in the '50s as a 2-seater homebuild in France - I don't think there were many built in this country apart from the types constructed by Rollason Aircraft Services. However, a group of de Havilland apprentices built a version with a different engine. This machine is still flying I think. It has a larger tail group and I have shown this on the plan. It could help the flying a bit (!) as these small models can be a bit lively.

The construction is fairly simple. The only tricky bits are the wing slots, which could be omitted as on a model of this size you hardly notice them.

Fuselage: Construct the fuselage using a basic 1/16 balsa sheet sided box with 1/16 x 1/4 and 1/8 sq spruce, or bass, longerons and spacers. F1 is 1/8 ply as the Thunder Tigre GP .07 is bolted to it. The rest of the formers are 1/16 ply, apart from the rear turtledeck which are 3/32 balsa with 1/8 sq spruce or bass stringers. The forward and cockpit decking is 116" balsa sheet covered in one piece, select a flexible piece of sheeting for this purpose.

The front lower fuselage bottom is 1/16 ply. It has two purposes; the first is that it stiffens the front fuselage and the second is to hold the front wing mounting dowel.

Wing: Construction of the wing is just like a bigger model scaled down. Actually I have used the full-size construction technique virtually scaled down rib for rib. The wing spars are 1/4 x 1/8 spruce top and bottom. The ribs are 1/16 sheet balsa. W2 is cropped for the slots and ailerons. The ailerons are centre hinged with Mylar tape, and driven by 16 swg torque rods..."

Update 17/3/2025: Added airfoil dat zipfile, thanks to Martin Huebner.

Quote: "Hello Steve and Mary, what a beautiful airplane! Attached you'll find the wing airfoil of the Druine Turbi (oz16025). Greetings,
Martin Huebner"

Supplementary file notes

Airfoil dat zipfile.
Article.

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