P-47D Stunt (oz8145)

About this Plan

P-47D Thunderbolt Stunt. Control line semi-scale stunt model. Fox .35 shown.

Quote: "Discover how designer Parrott met the long-time taboo of excessive frontal area head on and came up with a crowd pleasing, contest winning Jug.

The famous 'Jug', workhorse of WWII, should be no stranger to the modeler or aviation fan. Known affectionately as 'the seven-ton gun platform', the Republic Thunderbolt had the desirable ability to absorb tremendous punishment and still bring home its valuable pilot. Armed with eight 50-cal machine guns, rockets and bombs, the P-47 was a formidable foe. Powered by the Pratt & Whitney R-2800, 2,000-hp radial engine, the Thunderbolt was not a sleek, streamlined fighter when compared with the Mus-tangs, Spitfires and ME-109's. However, the P-47 has its own beauty, giving the appearance of a powerful brute, which indeed it was.

Scale models of this aircraft are popular, but it has been passed over for semi-scale control line stunt like other radial engine types because of the amount of frontal area. I have long believed that this problem could be successfully solved, and so that project was begun. It has taken a little over two years to produce the model shown here.

In designing the P-47D, two goals were set. First, to design a stunt model that was as least as good, if not better, than the top present day stunters. Second, to compromise only where necessary the scale appearance of the model. The Thunderbolt has attained both these goals. I hope it will encourage others who may have passed up a radial engine prototype. There are many popular types which used radials.

Let's talk about frontal area, and consider two types. First, we have 'real' frontal area, and second, 'apparent' frontal area. The first is the actual area which must penetrate the air, and if too great or too blunt, will create excessive drag and undesired aerodynamic effects. Consider holding a ping-pong paddle out of the window of a moving car. If the broad side of the paddle is presented to the air, considerable force will be exerted against the blade, and it will have a tendency to move up and down or, in other words, be unstable. Turn the paddle so that the thin edge is into the wind. It will penetrate easily, and unless moved, will remain stable. Cut the center out of the paddle, leaving only a small outline. We find that the paddle will now act the same, no matter which side is presented to the wind. The paddle still looks as big as before. This is 'apparent' frontal area. This is what the P-47D has, and the only thing it affects is the appearance points. To 'cut the center out of the paddle' something had to be done with the air rushing in the larger cowl opening of the Thunderbolt. Since there is no spinner to break up the airflow, an angled firewall is used in conjunction with a streamlined cowl interior to achieve the same effect. A close examination of the front view of the Thunderbolt will reveal it actually has less frontal area (real) than the average stunter!

The D version of the P-47 was chosen for several reasons. In addition to being one of the cleaner models of the Jug, it has less side area than the greenhouse and turtle deck versions. I consider side area undesirable, and for this reason the dorsal fin, which was on the later D and N models, was omitted. The scale outlines, and markings were obtained from the book 'The P-47 Thunderbolt', Famous Aircraft Series. I chose the D-day markings (See pg.72) and checkboard cowl which appera in a photograph there..."

Direct submission to Outerzone.

Update 29/10/2016: Added article pages, thanks to Pit.

Supplementary file notes

Article pages, text and pics.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction