Boeing 2707

The Boeing Model 2707 (up to September 1966 Model 733 ) was the project of a supersonic transport aircraft of the U.S. manufacturer Boeing.

History

Boeing's research in the field of civil supersonic flight began in 1952, but were discontinued after a short time, it became clear that the cost of the design and manufacture of a corresponding prototype would exceed the capabilities of a single company wide. By 1958, only conceptual studies were conducted only after the project status has been achieved, finally founded 1966 " supersonic transport department " ( Supersonic Transport Division ) at Boeing. Together with Boeing worked by NASA and other U.S. aircraft manufacturer in the solution of problems in this area.

1963 also saw the American government that the cost of developing a supersonic transport aircraft are not applied by a single manufacturer and announced a design competition for an American SST (Super Sonic Transport ) to. The financing of one or more prototypes of the winning design should be done by state agents then mostly. Since no adequate engine for the SST was available, a turbojet engine in the 35,000 to 40,000 lb class ( 156-178 kN) should be developed in a separate competition.

The development was funded by state grants from the SCAT project (Super Sonic Comercial Air Transport ), later SST project, which stretch out 75 % of the development costs.

Competing designs in the SCAT project were the Lockheed L -2000 and the North American NAC - 60th However, the NAC -60 retired prematurely due to high air resistance. In addition to General Electric also Pratt & Whitney and Curtiss -Wright competed for the engine order. Also Curtiss -Wright resigned.

Model 733

At the end of the first phase of the SST competition in January 1964, Boeing presented a draft of 150-227 passengers, who received the factory designation Model 733. The planned cruising speed was Mach 2.7 ( about 2,900 km / h). Here, the expected result of the heating of the air cell to air friction forced designers to provide a titanium alloy, instead of the usual aluminum alloy in the aircraft industry for the structure. The Boeing 733 had a relatively conventional fuselage with tail and four individual engines in nacelles. These were supposed to be among the non-pivoting wing approaches ( similar to where later in the Rockwell B -1 or Tupolev Tu- 160, the engine nacelles were mounted on two engines). The wings were pivotable between a sweep of 74 ° and 20 °. In the 20 ° position, the supersonic aircraft should be able to get by with the same runways as they were needed by the then intercontinental aircraft.

2707-100

Even before the end of the second phase of the SST competition covered in September 1966, Boeing, the expected profitability of the previous concept and then put a revised, enlarged draft, which was now called the Model 2707 or B- 2707. The old designation Model 733 has been completely dropped. The swing-wing design was indeed retained, but the passenger capacity increased to over 300 passengers (other sources indicate only 241 ) and moved the engines to the rear under the surfaces of the horizontal stabilizer. In the fully tilted backward state, the structure formed a delta wing. To improve the low speed flight triple - slotted flaps and slats were provided.

To improve visibility during takeoff, landing and rolling a retractable nose was introduced. To ensure the necessary ground clearance a second joint was earlier provided to pivot the radomes slightly upwards can.

2707-200

On December 31, 1966, the Federal Aviation Agency as the winner of the Boeing SST competition and General Electric announced as the winner of engine competition. On September 23, 1969 Richard Nixon approved the construction of two prototypes, the first flight for the beginning of 1973 and the beginning of production for 1973/74 was considered realistic. The approval should take place in 1978. Since the 2707-100 in the wind tunnel had problems with stability, it has been further developed for Boeing 2707-200. This had a longer fuselage and additional canards, which led to significant excess weight. The 2707-200 would have 292 seats in 97 m length.

2707-300

In the meantime, Boeing had cut the use of a pivoting wing of the concept and looked for the 2707-300 a fixed delta wing before together with a conventional tail unit. The wing structure should be from the original Plattenbeplankung ( Maschinenbeplankung ) converted to a Sandwichbeplankung. The four engines were mounted in individual nacelles at the wing trailing edge. The machine has been shortened. The new version should have just 234 seats. Unlike the competition from Tupolev and Concorde they should have at the rear a classic tail with elevators. The measures provided for 2707-300 General Electric GE4/J5P would each have a thrust of 290 kN - 222 kN and had no afterburner. The consumption per engine would have been 35,000 l / h or 14,200 l / h without afterburner.

End of program

1970 26 airlines orders had already given up a total of 122 aircraft. However, before the construction of two prototypes could actually start, the U.S. Congress placed the project on 24 March 1971. These decisions were confirmed by the oil crisis of 1973, as passenger traffic at supersonic aircraft became unprofitable by this. The dummy very elaborate crafted the 2707-200 has been sold and is still located in an amusement park in Florida. The Hiller Aviation Museum today has a portion of the retractable nose in his collection.

The Smithsonian still has a General Electric Turbojet GE4.

Construction

The planned cruising speed of about Mach 2.7, the hull heated by air friction to over 200 ° C, so that aluminum is no longer usable as a structural load-bearing material. The machine should therefore be made of a titanium alloy, and also receive a double body casing in order to minimize the risk of decompression in the altitudes of up to 21,000 meters.

Orders

  • CP Air: 3
  • Delta: 3
  • Eastern Airlines: 3
  • Iberia: 3
  • KLM: 3
  • World Airways: 3
  • Aer Lingus: 2
  • Aeronaves de Mexico: 2
  • Braniff Airways: 2
  • El Al: 2
  • Pakistan International Airlines ( PIA ): 2
  • Trans International Airlines ( TIA ): 2

Specifications

Curtiss-Wright Federal Aviation Administration Canard (aeronautics) Eastern Air Lines Aeroméxico Boeing XPB Boeing-Stearman Model 75 Boeing 247 Boeing 307 Stratoliner Boeing 314 Boeing Business Jet Boeing 367-80 Boeing 7J7 Boeing Pelican Boeing Sonic Cruiser Boeing X-40 NASA X-43 Boeing X-48 Boeing X-53 Active Aeroelastic Wing Boeing Yellowstone Project#Yellowstone projects
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