B-307 ✪ Stratoliner
Medium-haul Passenger Aircraft
Model B-307 Stratoliner, originally the project was called Model-300 and was developed simultaneously with the Model-299 bomber, the future B-17, taking a bomber as a basis, made an airliner. The new aircraft had a high-altitude system that allowed it to fly at an altitude of 7500-7800 m, above thunderclouds.
The wing, tail unit, engines and landing gear were entirely taken from the B-17C (slats were additionally installed on the outer consoles on the wing). The fuselage was completely redesigned: it had a circular cross-section so that the air pressure at high altitude was evenly distributed, and the diameter increased by 1.07 m forced a corresponding increase in the center section, while the wingspan increased from 31.39 m for the B-17 to 32.68 m at the 307th.
The salon accommodated 33 passengers in the "daytime" version or 16 beds plus nine seats in the "nighttime" version. The high-altitude system had an SCR with supercharging from two compressors driven by internal engines through power take-offs and countershafts, providing a pressure in the cabin at an altitude of 7000 m, equal to atmospheric pressure at an altitude of 3600 m.
December 31, 1938 - the first flight of the model 307 prototype (register NX-19901, serial No.1994). The aircraft was equipped with 900 hp Wright GR-1820-G-102 "Cyclone" radial geared engines. from. with screws "Hamilton Standard Hydromatic" Model-ЗЗЕ50 with a diameter of 3.5 m.
On March 18, 1939, the prototype crashed, falling into a tailspin when one engine was turned off, all on board were killed. As a result of the investigation, the aircraft were urgently altered: they installed an enlarged keel with a fork, increased ailerons, and installed slats on the outer wing consoles.
In 1942, TWA * - Transcontinental & Western Air aircraft were requisitioned by the US Air Force, designated C-75. With the capacity to accommodate 33 passengers and with a crew of five, they were used to carry senior civil and military officials on transatlantic flights. For two and a half years, the C-75 aircraft made more than 3000 flights.
In 1944, the aircraft were returned to the company and underwent a deep modernization. The wing and engine nacelles were replaced by the wing from the last production version of the B-17G, the stabilizers were also borrowed from the B-17G (they had a noticeably larger span and a different shape in plan) and were moved back 90 cm.The engines were also new. The electrical system has been completely renewed like the B-29, and the passenger capacity has been increased to 38 people.
Approx. * - airline TWA - Transcontinental & Western Air in 1946 renamed Trans World Airlines