Some nervous patriots seem to be under the impression that Germany's Focke-Wulf 190, and Japan's Mitsubishi 00 and Sento KI-001 are unanswered challenges to US designing ingenuity. Kurt Tank boasted that his FW-190 with its 1,600-2,000-hp fan-cooled radial could open up its three-stage supercharging system and dive down on anything that flies at 40,000 feet. Both the 00 and 001 are supposed to climb like skyrockets. The publicity that emanates from Herr Goebbels' microphone and Tokyo's mimeograph would make some Americans believe that the Axis had the upper air all to itself notwithstanding the fact that the high-flying Republic Thunderbolt (P-47) has been widely discussed and geared for quantity production for some time. Apparently nobody was listening.
The P-47 is a big ark probably the biggest single-engined single-seater in service. It has a 40-foot span, a 35-foot fuselage, stands 12 feet 8 inches high and weighs about six and three quarter tons.
Its power plant is a 2,000-hp-plus turbo-supercharged engine, which swings a 4-bladed, 12-foot Curtiss propeller. It is armed with six or more heavy-caliber machine guns and practically every cubic foot from spinner to rudder and between position lights is packed with equipment for flight or homicide.
While specific information on the Thunderbolt is still none of the enemy's business, it can be safely stated that the P-47 climbs like a homesick angel; at 20,000 feet, the highest altitude at which it can be clocked accurately, it is considerably faster than the "incredible" FW-190 and its best performance is at an even higher altitude! For those who are still worried about America's chances in the upper air, it may be some comfort to know that the P-47's top ceiling thus far has been limited by how little external pressure the pilot could take.
Looking head-on at the P-47 as it taxis up the runway, blowing up a miniature dust-storm, it resembles a charging bulldog with its gaping fifteen-and-a-half foot landing gear tread, oval-faced cowling, and heavy-coupled lines. By what were until recently orthodox design ideas, this should be a middle-speed barge, big and luxurious. But don't be deceived by that over-stuffed, snub-nosed appearance. The philosophy that dictated needle-snouted fighters was on the decline when fighter craft zipped past the 360-mph mark. Somewhere about that speed there is a point where skin friction, the drag that even a smooth surface causes, begins to square. This mounts up until the resistance accumulated along the long cowling lines of a small-frontal-area liquid-cooled engine equals that of the broad frontal area and short cowling of an air-cooled power plant. When one approaches or reaches that point, the disadvantages of an air-cooled engine are minimized or completely disappear. Here the air-cooled vs liquid-cooled controversy raises its ugly head, but since the P-47 seems destined to carry much of the combat load during the next year, there can be no harm in extolling the radial's virtues. Not the least of these is durability.
Not many months ago, the Swedish magazine Flyg och Motor reprinted a survey from the authoritative German publication Luftfahrtforschung. It contained a detailed examination of over a hundred radial air-cooled engines which had been damaged in combat and had still managed to produce enough power to effect safe landings in home territory. There were some cases where 30% of the cooling fin area had been stripped; others had cylinders completely holed through, heads knocked off, rocker arms chipped, push rods severed, etc. Still, they managed to produce enough power to keep going. The lubricating system seemed to be the only vulnerable area, and the article offered suggestions for armoring this.
Probably the curtest, but most comprehensive survey on the fighting possibilities of the P-47 came from L L Brabham, currently Republic Aviation's operations manager and the first man to fly the Thunderbolt, in May of last year. While direct quotes are not permitted, he offered certain interesting facts. The P-47 is a flyable airplane. It has a sound background, and many of its characteristics are the result of pilot's suggestions. In 1940 Alex Kartveli, Republic's chief engineer, and Hart Miller, the company's representative to the Army, went to the Air Forces Material Division at Wright Field to review specifications on the P-44. This was an improved P-43 with six guns, a 1350-hp engine and the latest equipment current at the time. Republic had sunk between 800 thousand and a million dollars in primary designs, research and mock-up.
Over a dinner table, Kartveli and Miller heard several Army test pilots give their opinions on what they would like to see in a fighter. Kartveli took the notes down on the back of a used envelope. Then he and Miller went home, scrapped the P-44 in mock-up stage and went to work on the P-47. There was no Thunderbolt mockup. The first manifestation of this current high-altitude terror, besides wind-tunnel models, was the XP-47. Since then the X-job has been a winged guinea-pig for such various modifications as must go into every new plane type.
While certain advantages have been demonstrated for tricycle undercarriages, the problem of making room for the nose-wheel gear in the already crowded front end of this single-seater dictated conventional landing gear. An extremely wide tread makes the P-47 easy to handle on the ground. Certain other types, the early Spitfire for one, demonstrated right hand ground-looping characteristics due to a narrow landing gear tread which had been installed as a means of accelerating take-off. Despite its wide tread, the Thunderbolt gets off well and can be operated out of some pretty rough fields. While military restrictions limit what may be described of the P-47's equipment, nothing of importance seems to have escaped attention. Places usually left empty in fuselage and wings are packed with flying or fighting gear. It is a big plane because it needs to be big there's a lot in it. How it gets that way is also none of the enemy's business just now, but the P-47's wing loading is higher than the Mitsubishi Zero's scant 20 pounds-per-square-foot, the Spitfire's 27, the Hurricane's 28. Still, its ceiling is phenomenal.
There was a period, not so many weeks ago, when reports of the Focke-Wulf 190's wicked high-altitude performance caused us considerable worry. Recently a specimen was captured in England intact. In a test flight it topped 370 mph and performed well at high altitudes. The figures were tabulated and sent to America. Some people thought we should have been frightened. Others, in the "know," look at the lengthening Thunderbolt production lines and say, "Cheer up, Buddy, wait till they meet the Thunderbolt!"
This article was originally published in the October, 1942, issue of Air Tech magazine, vol 1, no 1, pp 14-15.
The original article includes 3 photos of the P-47 and photos of P-35, Guardsman, P-43 Lancer, FW-190, and a battle-damaged Cyclone engine.
Photos are not credited.