The first B-1A rolled out on October 26, 1974 and created its maiden flight on December 23 1974. In 1974, AIL was awarded the development contract for the B-1 ECM system; the foremost comprehensive ECM program ever initiated. the development schedule was in more than4 years and was for a 77 Line Replaceable Unit (LRU) band 4 through 7 system. AIL Subcontractors included Litton, Sedco, Northrop, and Tasker. The third prototype, designed as an avionics testbed, carried the initial AIL AN/ALQ-161.
The B-1A design includes four jet engines with afterburner, with two jet engines located below each wing root. The fuselage and wing are blended together, and the variable geometry permits a 15 wing sweep in the forward position and 67.5 when totally swept. The B-1A employs a sensor-controlled automatic system, using movable foreplane vanes to combat low level turbulence. The three bomb bays are capable of carrying eight SRAMs or 25,000 pounds of nuclear or standard bombs each. in addition, there are four external exhausting points each capable of carrying two SRAMs or 10,000 pounds of bombs.
The B-1A has a crew of four: pilot, copilot, offensive systems operator, and defensive systems operator. Originally, the crew was in an escape module, however ejection seats were substituted to save cost and weight. The B-1A has a length of simply over 150 feet, a wing span of 136 feet, 8.5 inches in a fully spread configuration and 78 feet, 2 inches in a swept mode, with a height of 33 1/4 feet, 7 inches. the maximum gross take off weight is 395,000 pounds. The engines have a self-start capability and, therefore, don't need cartridge begin.