One of the advantages of an aircraft with movable wings is that it can land on short runways with its wings in front, then take off with full load and reach supersonic speeds in a short time with its wings in the rear position.
The Mig-31, which emerged in the 1980s with an advanced radar system and capable of sending long-range missiles to the enemy aircraft from great distances, was thought to pose a threat to the B-1B, and some parts in the fuselage were replaced with various special materials that absorb radar echoes, and the B- Adjusted the radar echo of the 1B to the radar echo of an F-16.