TheBoeing B-52 Stratofortressis a long-range,subsonic,jet-poweredstrategic bomber. The B-52 was designed and built byBoeing, which has continued to provide support and upgrades. It has been operated by theUnited States Air Force(USAF) since the 1950s. The bomber carries up to 70,000pounds (32,000kg) of weapons.[4]

Beginning with the successful contract bid in June 1946, the B-52 design evolved from a straight-wing aircraft powered by sixturbopropengines to the final prototype YB-52 with eightturbojetengines andswept wings. The B-52 took itsmaiden flightin April 1952. Built to carry nuclear weapons forCold War-eradeterrencemissions, the B-52 Stratofortress replaced theConvair B-36. Although a veteran of several wars, the B-52 has dropped only conventional munitions in combat. The B-52's official nameStratofortresshas been used rarely in informal circumstances; it has become common to refer to the aircraft as theBUFF(Big Ugly Fat Fucker).[5][N 1]

The B-52 has been in active service with the USAF since 1955. As of 2012, 85 remain on active duty with nine in reserve. The bombers flew under theStrategic Air Command(SAC) until it was inactivated in 1992 and its aircraft absorbed into theAir Combat Command(ACC); in 2010 all B-52 Stratofortresses were transferred from the ACC to the newAir Force Global Strike Command(AFGSC). Superior performance at high subsonic speeds and relatively low operating costs have kept the B-52 in service despite the advent of later aircraft, including the canceledMach3North American XB-70 Valkyrie, thevariable-geometryRockwell B-1B Lancer, and thestealthNorthrop Grumman B-2 Spirit. The B-52 marked its 50th anniversary of continuous service with its original operator in 2005 and after being upgraded between 2013 and 2015 it will serve into the 2040s.[N 2]