B-1 Lancer

The Rockwell (now part of Boeing) B-1 Lancer is a four-engine supersonic variable-sweep wing, jet-powered heavy strategic bomber used by the United States Air Force (USAF). It was first envisioned in the 1960s as a supersonic bomber with Mach 2 speed, and sufficient range and payload to replace the Boeing B-52 Stratofortress. It was developed into the B-1B, primarily a low-level penetrator with long range and Mach 1.25 speed capability at high altitude. It is commonly called the "Bone" (originally from "B-One").
The B-1B is expected to continue to serve into the 2030s.

The B-1 has a blended wing body configuration, with variable-sweep wing, four turbofan engines, triangular fin control surfaces and cruciform tail. The wings can sweep from 15 degrees to 67.5 degrees (full forward to full sweep). Forward-swept wing settings are used for takeoff, landings and high-altitude maximum cruise. Aft-swept wing settings are used in high subsonic and supersonic flight.

Video Clip: The B-1B Bomber (6:58)