Boeing B-52 Stratofortress

The Boeing B-52 Stratofortress is a strategic bomber brought into service in 1955, under the aegis of the Strategic Air Command of the US Air Force. 744 specimens were built, 1954-62, of which 90 are always in service at the beginning of the XXI° century, that is to say more than 50 years after its first vol. the nickname of the B-52 testifies to its imposing nature: BUFF ( Conceited Big Ugly Fellow ; in French, “large fatty and ugly guy”).

Conceived in the beginning to carry the Nuclear weapon, the B-52 was modified thereafter for the conventional bombardment, then the transport of cruise missiles. The B-52 played a role in the Guerre of Vietnam, the Guerre of Kuwait (1990-1991), the conflict of Afghanistan of 2001, and the Guerre in Iraq (2003-2006).

History

The studies which led to the B-52 started immediately after the end of the Second world war: an invitation to tender was emitted in September 1945, and the original proposal of Boeing (a kind of B-29 increased, with a scale of 67m and motorized by 6 Turbopropulseur S) was accepted in June 1946. However, the manufacturer spent the 4 years which followed to modify its project because of many changes of opinion of the American Staff, which failed more once to cancel all the program.

Finally, a contract was signed in 1950 and two prototypes were built. The first of them made its inaugural flight on April 15th 1952, flight which lasted a little more than 2 hours. Completely modified compared to the proposal of 1946, it was now about a plane of 56 meters scale, with a Sweptback wing with 35 degrees, propelled by 8 engines Pratt & Whitney J57. The B-52 was equipped with a pneumatic system complexes supplied with air bled on the compressor of the engines, intended in particular to provide electrical energy necessary to the various equipment.

After the many trial flights appeared B-52A , version of preproduction which incorporated several modifications like before redrawn and lengthened completion, of the more powerful J57 engines, a system of in-flight refueling, etc but always did not have any electronics component of navigation and bombardment. It was thus necessary to await 1954 and B-52B to have a really operational plane. The half of the B-52B was also capable of reconnaissance missions: their bomb bay could indeed carry 2 containers of equipment such as various cameras, radars and detectors.

The deliveries with the Strategic Air Command started in 1955 and a certain number of problems appeared as of the following year: on the level of the engines, system of bombardment, alternators, etc Twice, the B-52 were temporarily prohibited vol. Parallèlement, a version B-52C was developed with tanks under the wings larger, a new system of bombardment and new alternators. All the B-52C were capable of reconnaissance missions. This version was followed at regular intervals by B-52D , was equipped with a new control system of shooting of the machine-guns of self-defense located at the back, then by B-52E , modified for the bombardment at low altitude by change of the system of bombardment and reinforcement of the structure, and finally B-52F , equipped with more powerful J57 engines and new alternators.

In 1959 was delivered the first specimen of the version B-52G . It was this time about a major revision of the plane: reduction of the weight of the structure, derives smaller, modification of the system of self-defense, improvement of the comfort of the crew, and especially of new wings able to contain additional fuel 15%. Two years later began the deliveries of the final version B-52H , only still in service currently, equipped with new engines TF33 offering 30% of additional power compared to J57, while being less noisy and more economic while carburizing. Moreover, the machine-guns of self-defense were replaced by a gun of 20mm.

The unit costs of a B-52 in 1961 were of 30 million dollars. The last apparatus was delivered in October 1962. Throughout their career (which is not finished yet), the B-52 underwent many modifications and updates intended to enable them to carry new weapons (cruise missiles for example), to improve their systems of electronic countermeasures or their other equipment of navigation/bombardment, and of course to correct various problems.

Engagements

B-52 was used in all the great conflicts in which the the United States took part since the years 1960: the War of Vietnam, the war of Kuwait, the war of Afghanistan of 2001 and war in Iraq.

Between 1959 and 1968, bombers B-52 were in alarm in flight permanently, with their nuclear weapons. But there were several accidents in particular in Spain in 1966 then in Greenland in 1968 (see Liste of the nuclear accidents). It is following the latter accident that these flights, baptized Chromedome, were prohibited on all the fighters American.

Production

XB-52 - first prototype
YB-52 - second prototype
B-52A - version of préproduction (3 specimens)
B-52B - first version of series (23 B-52B and 27 RB-57B)
B-52C - larger tanks, new system of bombardment (35 specimens)
B-52D - new system of self-defense (170 specimens)
B-52E - reinforced structure, new system of bombardment (100 specimens)
B-52F - more powerful engines (89 specimens)
B-52G - modification of the structure of the plane (193 specimens)
B-52H - new engines TF33 (102 specimens)

Full number of produced planes: 744

References

Random links:

Production companies of French television programs | Tamarinier | Phan Thị Vàng Anh | First district of the Flowering ash | Open of Valence 2007