Boeing 367-80

In the 1940s, the Boeing Company held a firm position among manufacturers of bombers, including on its account such famous aircraft of the Second World War as the B-17 Flying Fortress and B-29 Superfortress . In 1947, its first flight was made by the B-47 Stratojet , which already had jet engines installed under the swept wing , which allowed it to reach higher speeds, which provided an advantage over obsolete aircraft with piston engines.

On July 27, 1949, a historic event takes place in the UK - the prototype de Havilland Comet , a jet airliner, made it possible to carry out passenger transportation at higher speeds and in higher atmospheric layers. In the summer of 1950, Comet was shown at the Farnborough Airshow , where William Allen present among the audience - Director of Boeing. Although the new aircraft at that time had not yet reached passenger routes, de Havilland had already received a package of orders for it. All the more tempting was the idea of ​​other aircraft manufacturers to create their own model of a jet airliner. One of them was Boeing, which decided to use its experience in building high-speed bombers, although it was quite risky, because at that time it did not have reliable customers among civilian operators.

In those years, Lockheed Corporation with its Constellation Connie and Douglas Aircraft with its DC-6 and the DC-7 created in 1950 dominated the American civilian aircraft market. To break this monopoly, it was necessary to create a fundamentally new airliner that would “burst” into this race, while leaving far behind competitors.

Creation

In 1952, the B-52 Stratofortress strategic bomber made its first flight. In the same year, the company secretly begins work on a prototype of a jet aircraft with swept wings. The new aircraft was supposed to be able to take off and land from runways with a length of 2100 m, and the cost of man-miles is lower than that of the Douglas DC-6 , which was widespread at that time. Due to the secrecy of work, the prototype received the designation of model 367-80 , since model 367 belonged to the transport piston aircraft C-97 Stratofreighter , created on the basis of the B-29 Superfortress and which served as the basis for a small number (56 pieces) of the passenger Boeing 377 Stratocruiser . In the company itself, the model received the nickname "-80" or "Dash 80" ( Eng. Dash 80 ). At the same time, the company primarily hoped to create a military transport aircraft based on the prototype, especially an air tanker, which was supposed to replace the outdated KC-97 Stratofreighter (created on the basis of the C-97), in connection with which the 367-80 model had no windows and a passenger compartment . Also, the diameter of the fuselage was taken equal to 3353 mm.

To reduce the development cost, the experience of creating a B-52 bomber was used, including the use of similar Pratt & Whitney J57 / JT3C jet engines, while due to the lower flight weight their number was reduced to 4 (for B-52 there are 8, and for B-47-6). Thanks to this, the creation of the project took only six months. Since at first there were no buyers for the promising model, the company carried out all work on its creation at the expense of its own finances. On May 15, 1954, a Boeing 367-80 first drove outside the gates of a factory in Renton , Washington . It was created in just two years, including one and a half years of construction, and the cost of its development, according to various sources, was from 15 to 16 million dollars, which at that time amounted to a huge amount; by comparison, this is 2/3 of the company's total net revenue since the end of World War II. To distinguish from previous airliners, the numbering of which began with 3XX, the new aircraft received the designation 707 , thereby symbolizing the transition to new speeds; in the company itself, the prototype still had the model designation 367-80 . After registration, he was assigned tail number N70700.

Trials

During trial runs on the strip on May 22, the left strut of the main chassis collapsed, while the engine nacelle of engine No. 1 was also damaged, which led to the need to delay the tests until the defects were fixed. Finally, on July 15, 1954, test pilots Alvin Johnston and Richard L. Loesch for the first time lifted the N70700 into the sky. During these flights, the aircraft’s tendency toward the “ Dutch step ” was noted, but the testers encountered this phenomenon on the B-47, and therefore it was not new to them. Also, sometimes there were problems with the engines, as a result of which the Dash 80 once even rolled out of the runway. But in general, the aircraft turned out to be very successful, including the idea of ​​placing the engines in gondolas under the wing made it possible to reduce noise compared to the British Comet or the Soviet Tu-104 , in which the engines were located in the root of the wing, that is, close to the fuselage . Also, there was no vibration characteristic of propeller-driven aircraft in flight, and the cost of passenger traffic per person mile was 20-30% lower compared to the common piston DC-6B.

The airlines initially did not show interest in the new aircraft, so Boeing tried to attract the attention of the military with its high-speed air tanker project, for which 367-80 was equipped with a mock-up of the refueling bar and performed a demonstration flight with the B-52 with simulated refueling in the air at new, higher speeds. The military initially refused, but then they were forced to agree, because while other manufacturers had projects only on paper, Boeing already flew a prototype. On October 5, 1954, a contract was signed for 50 new aircraft. A military aircraft was created in two versions at once: a transport C-135 ( Eng. Cargo aircraft - a transport aircraft , model 135 ) and a KC-135 tanker ( Eng. Kerosene tanker - a tanker ). On July 20, 1956, the factory in Renton immediately released the first production KS-135A, which received the name The City of Renton ( Rus. City Renton ) and was 3454 mm longer than the prototype. In total, more than seven hundred of these aircraft were built.

On August 6, 1955, a Boeing 367-80 participated in an air show in Seattle, and its flight was recorded by cameras on board the aircraft and from other aircraft. This flight went down in history when, to everyone's amazement, when flying over Lake Washington and Seattle, test pilot Alvin Johnston, on a prototype of a transcontinental airliner (!), Twice (!!) completed a “ barrel ” (!!!) ^[2] . After this flight, William Allen called Johnston to his "carpet" and demanded that he never again engaged in "air hooliganism." To this, Alvin Johnston replied that he was “selling airplanes” and was fully confident in the safety of this flight. On October 16, 1955, the N70700 flew non-stop flight on the Seattle - Washington route with a length of 3770 km.

Such flights had an effect and on October 13, 1955, Pan American World Airways made an order immediately for 20 model 707 aircraft, and then orders began to come from other carriers. It is worth noting that the Boeing 707 at the design stage had a fuselage with a diameter of 3658 mm, that is, wider than the prototype, which allowed to increase the number of seats in the row from 5 to 6. The military version received the same fuselage - C-135 / KC-135, the production of which already started. However, the Douglas Aircraft company was not going to give up positions and acted in a rather original way - it built life-size models that made it possible to compare the transverse dimensions of the B707 and DC-8 , clearly demonstrating that its aircraft has a 76 mm wider fuselage. After that, Boeing began to lose orders, but stubbornly refused to change the size of the fuselage, as it threatened to delay production. Cyrus Smith put the final point in the dispute - Director of American Airlines , who said that he would not buy a single 707th until they had a fuselage wider than the DC-8 by at least 1 inch. After that, the diameter of the fuselage B707 was increased to 3759 mm; a fuselage with a similar cross section was later used on models 727 , 737 and 757 .

On March 11, 1957, a flight of 3,780 km from Seattle to Baltimore was made, while passengers on board were served by flight attendants from American Airlines , Braniff International Airways and Trans World Airlines . Due to getting into the high-altitude jet stream , this flight took 3 hours 58 minutes, and the ground speed sometimes reached 1123 km / h, which exceeds the speed of sound . On December 20, 1957, the Boeing 707-120 prototype made its first flight, and in all about a thousand aircraft of this model were produced, including a shortened version of 720 .

Further fate

Since 1957, when the mass production of the Boeing 707 began, the Boeing 367-80 was already used as a test aircraft, on which various technical solutions were tested, such as flaps with blowing of the boundary layer . Also, during the creation of the Boeing 727 , model 367-80 carried out test flights, during which a model of a nacelle was placed at the top of the tail part, due to which an original appearance with five engines appeared. In 1969, the N70700 was set aside from flights, having at that time a total operating time of 2346 hours and 46 minutes of flying time and 1691 take-off-landing cycles.

On May 26, 1972, Boeing donated Model 367-80 to the Smithsonian Institution National Aeronautics and Astronautics Museum . In 1990, the prototype at the Davis-Monten airbase ( Arizona ) underwent restoration, and on August 27, 2003, it was placed in the original yellow-brown livery in the building of the Stephen Udvar-Hazy Center ( Eng. Steven F. Udvar-Hazy Center ) near the airport Dulles in Washington .

Main characteristics

• Crew - 3 people.
• Length - 38 964 mm.
• Height - 11,582 mm.
• Wingspan - 39 522 mm;
• The tail swing is 12,090 mm.
• The wing area is 223 m².
• Sweep angle - 35 °.
• The lengthening of the wing - 7.
• The maximum take-off weight is 86,180 kg.
• The mass of the empty plane is 34 310 kg.
• The volume of fuel tanks is 57,280 liters.
• Engines - four Pratt & Whitney JT3C turbojet engines with a pulling force of 4,540 kg each.

Operational characteristics

• The maximum speed is 937 km / h at an altitude of 7600 m.
• Cruising speed - 886 km / h, 0.8 Mach numbers .
• Flight range - 5680 km.
• Practical ceiling - 13 110 m.

Further development

• Boeing KC-135 Stratotanker
  • Boeing C-135 Stratolifter
• Boeing 707
  • Boeing 720

Competitors

• Convair 880
• Douglas DC-8

• The Boeing 367-80 . - Seattle, Washington: The Boeing Company, 1994 .-- 13 p. - (American Society of Mechanical Engineers).

• Model 367-80 Boeing: Historical Snapshot .
  • 707/720 Commercial Transport . Boeing: Historical Snapshot .
• Bryan R. Swopes. July 15, 1954 This Day in Aviation (2017). Date of treatment March 11, 2019.
• Boeing 707 (Russian) . Corner of the sky . Date of treatment March 11, 2019.