Bell P-39 Airacobra (oz14554)

About this Plan

Bell P-39 Airacobra (Ivan's Iron Dog). Peanut scale model WWII fighter, for rubber power.

Quote: "The P-39 was built like a tank; in Soviet service it proved deadly against the Nazi panzers. Ivan's Iron Dog, by John Berryman.

The P-39, the airplane nobody loved. Our own fliers called it the 'Iron Dog.' Minus its turbocharger, and shipped to the British, it was judged unsuitable for combat in Europe. We even tried to sell a few to the French, but the country fell before they arrived. Saburo Saki, the famous Japanese Ace, shot themdown in droves. Quite an inauspicious beginning for what may have been the first single-engined fighter to exceed 400 mph in level flight.

But the Russians, who were starving for aircraft of any description, used them, and used them well. With its powerful 37mm cannon firing through the spinner, it was an efficient tank-buster in the early days of the war. Its trike gear must have also made it amenable for use on primitive Russian air-fields as well.

If anyone ever loved the P-39, it had to have been the Russians and we modelers. Finally, a WWII fighter with a decent nose moment, a fair-sized tail, and a bit of 1930s 'Bill Barnes-ish' panache, as well.

This peanut model may look familiar to those of you who were fortunate enough to pick up Model Builder's plan book of WWI! aircraft. It should because it's a reduction (and alteration) of Clarence Mather's P-39 Airacobra (oz3518). If you compare the two sets of plans, you'll see that the wing construction has been changed considerably and that all the wood has been appropriately down-sized for proper peanut construction.

In addition, I chose to use a home-brew prop of my own design on my Iron Dog. This is one model that won't need much nose weight; in fact, if you use a plastic prop, you may end up nose heavy. Mine weighed 6.5 grams (no rubber), and the CG ended up at about 10 percent (more about this later). While not a beginner's model, construction is straightforward for anyone who has ever built a few peanuts.

Flight Surfaces: Assemble the tail feathers (5-pound, 1/20-inch stock), and build the wing in the usual manner. I chose to use heavier 7-pound, 1/16-inch stock for the leading edge of the wing, as it does take a beating. The balance of the wing was assembled from 4-to 6-pound stock, in the sizes called for on the plans.

All the curved surfaces of the flight surfaces were laminated from two pieces of 1/40-inch that were soaked, and bent around appropriately sized cardboard forms. They were then glued while still damp with white glue. If you've never used this procedure before, I urge you to try it, as it's very light and strong. I also urge you to remember to wax the forms, or you may never get the tips off..."

Direct submission to Outerzone.

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