wdolson
Posts: 10398
Joined: 6/28/2006 From: Near Portland, OR Status: offline
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quote:
ORIGINAL: Joe D. When it comes to Japanese aircraft development, you have me at a disadvantage. However, consider the following public domain "cut and paste" re the development of the A5M Claude, which I assume is the precurser to the A6M Zero: In 1932, the Imperial Japanese Navy (IJN) issued a requirement for a new naval carrier fighter, and in response a Mitsubishi design team under Jiro Horikoshi developed the "1MF10" fighter, which had a strong resemblance to the American Boeing P-26 "Peashooter" fighter, being a low-wing monoplane, with a metal fuselage and fabric-covered wings; an open cockpit; an air-cooled radial engine, driving a two-bladed fixed wooden propeller; fixed landing gear; twin 7.7 millimeter (0.303 caliber) machine guns in the upper lip of the engine cowling; and a telescopic tube gunsight. The first of two prototypes performed its initial flight in March 1933. The second prototype followed shortly after and differed from the first by replacing the strut-braced main landing gear with main gear in spats. The 1MF10 was an unlucky aircraft. It failed to meet IJN performance requirements and both prototypes were lost in crashes. It did, however, give Horikoshi and Mitsubishi a basis for further work. In 1934, the IJN issued another request for a carrier fighter, and Mitsubishi and Horikoshi came up with a new design, the "Ka-14", with the same overall configuration as the 1MF10 but cleaner, and featuring all-metal construction, an inverted gull wing, and a Nakajima Kotobuki 5 nine-cylinder radial providing 410 kW (550 HP). The initial prototype performed its first flight on 4 February 1935. The prototype exceeded its speed requirements, but it had a number of handling problems. As a result, the inverted gull wing was replaced in the second prototype by a flat wing with a slight outboard dihedral. The second prototype also featured an uprated Kotobuki 3 radial with 475 kW (640 HP). Four more prototypes were built that were similar to the second prototype, differing in small details and being used to evaluate a variety of engine fits. Following successful trials, the IJN approved production of the type as the "A5M1" or "Type 96 Carrier Fighter Model 1", powered by a Kotobuki-2-KAI-1 engine with 430 kW (580 HP). Looking at photos of these two planes, the A5M is the spitting image of the earlier P-26, at least from the outside. Is this just a coincidence? And if the lineage of the A6 goes thru the A5, and the same team that deveolped both planes was "inspired" by the US P-26 design for its A5 prototype, how original is the A6? To paraphrase Ecclesiastes, it looks like "there's nothing new under the (rising) sun." The A5M may have been influenced by the P-26 in appearance. In 1932, the P-26 was one of the world's most advanced fighters, so it would not be surprising for an up and coming power to make a fighter that looks like one of the world's best. It's almost certain that the Japanese did not get their hands on a P-26 before the A5M had been in front line service for a while. Their first opportunity was in China where a handful were operated by the Chinese, but the Chinese didn't get any until 1936. The only export operators of the P-26 before the start of WW II was China, Spain, and the Philippines (who got USAAF cast offs). Some USAAF cast offs also went to Honduras during the war. Two were recovered in the 1960s by Ed Mahoney of the Planes of Fame museum in Chino, CA. One of these went to the either the USAF museum or the Smithsonian (I don't remember which), the other was restored to flying condition and is still in Chino, though not flown anymore. A lot of planes look like one another. Japanese early war fighters looked like a lot of other single radial engine planes from the late 1930s. There were some similarities with some Italian fighters and the Zero and Oscar for example. Those Japanese fighters also had some similarities with the P-36, which evolved into the P-40. The AT-6 was not designed for combat and the Australian's attempts to build a combat version, the Wirraway, was not very successful. If you look at a stock AT-6 side by side with an A6M2, the A6M2 looks more similar to other late 30s radial engine fighters than it does the AT-6. The AT-6 has a different tail, different cowling, different canopy, different shaped wings, and a lot of other differences. For Tora, Tora, Tora, the production company also had some Vultee BT-13s modified into Vals. The stock BT-13 looks nothing like a Val http://www.warbirdalley.com/bt13.htm, but could be made to look like the dive bomber. Those planes were modified for the movie because they are plentiful, cheap, and with some heavy cosmetic surgery, they were able to transform them into look alikes for the originals. I have seen the insides of both an AT-6 and a Zero. They are radically different designs. The AT-6 is a rather old fashioned tube construction with a metal skin over it instead of fabric. The Zero is a typical late 30s fighter design with a stressed metal skin. The AT-6 is built from the ground up to take rough handling from student pilots and to have some performance, but not as much as a fighter. The Zero is designed from the ground up to be super light and maneuverable with extreme range. Very different missions and very different designs. It's a coincidence that one can be modified to cosmetically look like the other. Bill
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