In 1922 slowly was finishing the race the production of 200 fighters MB-3A, which Boeing built in licence of the company Thomas-Morse, and William Boeing started looking for a new type, which would ensure a factory job. After the experience with the all-wood construction MB-3, the designers of the Boeing began to focus on new technologies that would ensure the new machine easier production and maintenance. The result of a study tour through Europe and also tests the three D.VII, which got a factory available from the army was to take, although a few years old, but in the US completely new Fokkerových construction methods. The effect of the proposal would be cautious probing between military pilots, how could they have imagined a good fighter.
The project received the factory designation of Model 15. The hull was all-metal, welded from steel pipes, instead of Fokkerova gas welding was used arc. In the bow was envisaged with the engine of the Wright-Hispano, as with the MB-3A, but with the front cooler. The wings were wooden and also match the practices of the company Fokker, as well as a strut in the shape of a N of steel tubes and chassis with a continuous axis. Soon the engine was replaced by the stronger an order of D-12, with the tunnel cooler converted under the bow, originally a straight wing with a thick profile of the Göttingen 436 should now trapezoidal outer part. Cover fuselage and wings remained the cloth. Fuel was carried in the 204 l tank in the fuselage and in a 57 l tank in the midsection.
The army was with the new proposal, the familiar and her growing interest resulted 4. may 1923 in the rental agreement, which is committed to deliver the engine and armament and completion of the machine test. More financial support but in the freshly peaceful period, could not afford. Company Curtiss had its own iron in the fire and expecting the opponent, supposedly that is why they even tried to delay the delivery of the engine D-12 your new rivals. The first takeoff of the Model 15 was 2. June, 1923, when Curtiss my prototype a long time ago to be flying, and after the factory tests was train shipped to the McCook Field. Here was the XPW-9 (experimental tank with a water-cooled engine no. 9 - this designation he was assigned until later, after the purchase of the military) was compared with an order XPW-8. Tapered wings and a tunnel radiator here military pilots excited enough that the company was the Curtiss even asked to test it also on your XPW-8 - and the company Boeing has contributed to the emergence of a number of Hawk, which was the main competitor of the Boeingových structures up to 30. years...
Boeing and Curtiss in the tests have proved as a much better machine than MB-3. Both had more or less the same concept, same engine, PW-8 was slightly faster, the XPW-9 had but the superiority in maneuverability and easier maintenance and overall, was preferred. Despite this we managed the first store to agree Curtissu, which received an order for 25 machines. 28. November of 1923, However, USAAS Boeingův prototype purchased, assigned him the above mentioned designation XPW-9 (serial 23-1216) and ordered the other two slightly modified prototypes (23-1217/1218). Both machines army took over the 1. may 1924. The first prototype, meanwhile, served to test different adjustments, for example new chassis with separate axes of the wheels and by oil-pneumatic dampers. The result of the other tests was finally an order for 12 machines , THE PW-9, which was closed in September 1924. The first XPW-9 at McCook Field underwent in February 1925 static tests to destruction, the other machine suffered the same fate in October 1928. The third machine remained in December 1928 flyable..
Olivově zelená / Olive Green