Boeing Model 15
The Boeing Model 15 (insert name: Boeing PW -9) was a single-engine, single-seat biplane fighter aircraft of the U.S. aircraft manufacturer Boeing.
The development of the machine began in 1922 when they tried to manufacture a type that could keep up with the contemporary English and French fighter planes. One first studied the structure of a Fokker D.VII. The hull of the model 15 was made from arc -welded steel tubes. The two made of wood and covered with canvas wings were connected by N- struts. First, the machine should be fitted with a license-built Hispano -Suiza HS 42, but it was decided to use the more powerful Curtiss D- 12th The tunnel-shaped radiator was mounted directly below the engine.
The army was interested in the pattern and made in a contract, dated April 4, 1923 for the intended armament and also financed the engine to test the machine. The first flight took place on 29 April 1923 and the machine took part in the hunter comparative flight of the U.S. Army in 1923. One of the competitors was the Curtiss PW -8. Here, the superiority of both models against the types in use showed. The machine of Curtiss was a bit faster, the Boeing Model 15 was a bit more agile and robust. First, the Curtiss design was preferred, but the cooler assembly and the tapered wing tip to wing outline of the Boeing machine should be adopted. According to these guidelines, the Curtiss XPW -8B, which eventually emerged the Curtiss P-1 Hawk was born.
Eventually, however, the United States Army Air Service purchased on September 28, 1923, now as Boeing XPW -9 (serial number 23-1216 ) designated machine and ordered two more, slightly adapted to Army demands prototypes. The two machines were delivered on 1 May 1924. It then two again slightly different series have been ordered by 12 (19 September 1924) and 18 (16 December of the same year ). The first production aircraft were delivered on 30 October 1926, brought to their destinations in the Philippines and Hawaii.
A machine was equipped with an all-metal wing, the last production aircraft (serial number 25-324 ) was provided for testing purposes with a turbocharged Packard 1A -1500 engine and received the Army designation Boeing XP - fourth
On October 26, 1925 more series have been ordered by 25 machines that were equipped with the improved Curtiss D -12C engine and the designation Boeing PW -9A received. The first delivery was made on 19 June 1926. From this type as there was a Boeing Model 68 (Boeing AT-3 ) labeled version with a 180 -hp Wright Hispano engine, but disappointed because underpowered. The last aircraft of this series received a Curtiss D- 12D engine and was designated Boeing PW- 9B. The machine performed well and there were other changes, such as the reinforcement of the hull of the PW9B, a change in the fuel system and larger main gear wheels, ordered two sets of this variant to 15 and 25 copies. As of July 9, 1927, the extradition. Again, the last machine of this series (serial number 27-202 ) was used as a prototype, with improved cooling, the original chassis but improved wheel brakes for the Boeing PW- 9D. Likewise, an aerodynamically balanced rudder was applied, which was later retrofitted to most PW- 9C machine. September 12, 1927 12 machines were ordered, which were delivered from 25 April 1928. The last machine of this series was equipped with the Curtiss V -1570 engine, and was given the new designation Boeing XP - seventh There were also versions for the Navy, which were named Boeing FB- 1 to FB -5 and, except for a few pieces of equipment were identical to the army machine. The last machine in the army service was retired in February 1934.
Technical data ( PW -9)
- Length: 7.10 m
- Wingspan: 9.70 m
- Height: 2.40 m
- Wing area: 24.1 m²
- Empty weight: 878 kg
- Takeoff weight: 1414 kg
- Powerplant: 1 × Curtiss D-12 with 315 kW
- Maximum speed: 257 km / h
- Range: 628 km
- Service ceiling: 5768 m
- Rate of climb: 496 m / min
- Armament: two forward -firing 7.62 mm MG and 110 kg of dropping weapons