The B-1B is a long-range strategic bomber, capable of flying intercontinental missions without refueling, then penetrating present and future sophisticated enemy defenses. It can perform a variety of missions, including that of a conventional weapons carrier for theater operations. The B-1B's electronic jamming equipment, infrared countermeasures, radar location and warning systems complement its low-radar cross-section and form an integrated defense system for the aircraft. The swing-wing design and turbofan engines not only provide greater range and high speed at low levels but they also enhance the bomber's survivability. Wing sweep at the full-forward position allows a short takeoff roll and a fast base-escape profile for airfields under attack. Once airborne, the wings are positioned for maximum cruise distance or high-speed penetration. The B-1B uses radar and inertial navigation equipment enabling aircrews to globally navigate, update mission profiles and target coordinates in-flight, and precision bomb without the need for ground-based navigation aids. Included in the B-1B offensive avionics are modular electronics that allow maintenance personnel to precisely identify technical difficulties and replace avionics components in a fast, efficient manner on the ground.