2000多套航模飞机图纸大全

Specifications: Motor: speed 400, 6 V Wingspan: 692 mm Length: 540 mm. Number of cells: 7-8 600AE/500AR Prop: Graupner 6x4 Weight: around 500-520 gr. Main sources: Books: Hasse Wind, Hävittäjälentäjä, Börje Sjögren, Suomen ilmavoimien historia 1, Brewster B-239 ja Humu, Kalevi Keskinen, 1970 Tampere Magazines: Pienoismalli, 2/89, Pentti Manninen Top : By Subject : Construction The Brewster Model 239 -------------------------------------------------------------------------------- Author: Marko Terava Browse articles by Marko Terava Hits: 1713 Rating: 8.53 Votes: 15 ---12345678910 (10 is best) Specifications: Motor: speed 400, 6 V Wingspan: 692 mm Length: 540 mm. Number of cells: 7-8 600AE/500AR Prop: Graupner 6x4 Weight: around 500-520 gr. Main sources: Books: Hasse Wind, Hävittäjälentäjä, Börje Sjögren, Suomen ilmavoimien historia 1, Brewster B-239 ja Humu, Kalevi Keskinen, 1970 Tampere Magazines: Pienoismalli, 2/89, Pentti Manninen Internet: http://www.airspacemag.com/ASM/Mag/Index/1996/JJ/ssbb.html http://www.danford.net/aahs.html http://www.danford.net/faf..html "[T]here were a small number of pilots who achieved notable success with the Buffalo and who might argue that the Buffalo was, in reality, a revolutionary aircraft which narrowly missed an opportunity for greatness." Background Brewster's little fighter is a controversial aircraft. The Brewster remains largely unknown to general aviation public. This is probably caused primarily by the lack of success in countries other than Finland. The Brewster was even voted by a group of Internet aviation fans for the worst fighter of World War II. It is also mentioned in two books that are titled The World's Worst Aircraft. The Buffalo is the only fighter from any era to have a chapter in both of them. As is often the case, the truth isn’t so straightforward. Finnish pilots were able to achieve good results with the Brewster. Coupled with mature tactics and well trained Finnish pilots, the results were convincing. Over 490 air-to-air victories were credited to Finnish Brewster pilots. This is a lot considering that there were only 44 planes to begin with. With one particular plane (BW-393), an amazing 41 aerial victories were achieved! Of course, the Brewster wasn’t the only factor here, but it was a significant one. The guys who flew the Brewster Model 239 here in Finland liked their ride. One of them was former squadron leader Joppe Karhunen: "The more we played with it, the more we liked it". He and other wartime pilots felt that it was indeed a very good plane. The Brewster could turn on a dime, and in the early days of the war it was also considered to be pretty fast against the Russian fighters. It had no nasty stall characteristics, it behaved nicely during landing, and the takeoff was easy with its wide landing gear. After all, this plane was designed for aircraft carrier use. It had a reliable engine which, when properly maintained, never let its pilot down. The Brewster also had exceptionally good range – it could remain airborne up to four hours. It had heavy armament, which was effective against the enemy aircraft. All in all, it was a good and reliable war machine and the pilots felt good about it. Development and production There is a lot of documented information available about the Brewster fighters. Some of this information is contradictory. I have tried to filter out the faulty information and include only what is true. Making a good fighter, or any airplane for that matter, has always been difficult. Many excellent planes were not successful with the first attempt. More tests and more prototypes were required before the engineers "got it right". Many airplanes have had numerous versions during the entire history of the model. Sometimes the last production model was very different from the first one. The Brewster fighter was not an exception. There were three main variants of Brewster. These were Models 139, 239, and 339. Only the last variant was called the Brewster Buffalo. All these Brewsters looked pretty much the same. However, there were real differences between these three variations. This partly explains the varying success when Brewster fighters entered frontline service during the war in various parts of the globe. In the mid 1930's the U.S. Navy presented a design request for a new carrier-based plane. Around that time the Brewster factory had finished the XSBA-1 divebomber, which saw its maiden flight in 1936. This plane has a lot of similarity to later Brewsters. This was natural because Brewster had already started building the Model 139 before the Navy presented its request. Brewster's planes had all-metal structure, a mid-wing, retracting undercarriage, hydraulic systems, and so on. This was all very new to the U.S Navy. Because the airplane functioned well enough, the Naval Aircraft Factory built 30 more of those divebombers. For the fighter competition the Navy received responses from Grumman, Seversky, and Brewster. Brewster's design was chosen. The Navy gave this project the name XF2A-1. F=fighter, A=factory=Brewster, 2=second fighter from the factory in series A, -1=first modification from basic model F2A. Brewster called the planes:Brewster Models 139, 239 and 339, whereas the Navy called these planes F2A-1, F2A-2, and F2A-3 respectively. The Brewster Model 139 saw its maiden flight on December 2nd, 1937 with Melvin Gough at the sticks. This handmade prototype was delivered to the Navy for test flights in January, 1938. During these tests a few deficiencies were revealed. The biggest problem was the considerably lower than promised top speed. Modifications were required to the cowling and to the rivets, which were changed. With these modifications Brewster now had a top speed of 480 km/hr. Test flights continued on with this newly-built prototype, and the Navy accepted Brewster Model 139 into production with the designation X2A-1. In June the Navy placed an order for 54 planes. At this point the Model 139 was still a significantly different plane than the one which came off the production line in 1939. It was this part of the production batch which later became the Finnish Brewster. The most visible difference was the lower cockpit canopy. So much so that normal-sized pilots had difficulty sitting comfortably and still seeing well in all directions. The Brewster factory was not well suited for mass production, and production began at slow pace. Nevertheless, the first 11 planes (139’s) coming off the production line were ready for the Navy by December, 1939. The official date for the F2A-1 entering service was December 8th, 1939. The U.S Navy VF-3 got it's first plane then, and by mid December the aircraft carrier USS Saratoga had 9 planes. This had historical significance as these Brewsters were the U.S Navy's first carrier-based monoplanes in operational service. These 11 planes were the only Model 139's that the U.S Navy got. The remaining 43 planes (not yet ready) were left to Brewster Aeronautical. There were many reasons for this, but mostly because the planes were delayed and were already seen as out-dated. Brewster had also already offered the Navy a new, improved Model 339. So the Finnish government got a chance to buy the remaining planes. The remaining planes were modified. All Navy equipment was removed: carrier equipment, guns and aiming devices, and all gauges. Engines had to be switched to an export model which was approved for selling abroad. Wright Cyclone nine cylinder radial engines (1820G-5) were installed (the 1820 is the same engine that powered, among other things, DC-3’s and B-17 bombers). It’s worth noting that these stripped-down planes were now labeled as Brewster Model 239’s. Finnish Brewsters were very close to the first 11 Model 139’s that the Nav