ELLSWORTH AIR FORCE BASE, S.D. – A B-1B Lancer General Electric F-101 turbofan engine is tested at Ellsworth Air Force Base, S.D., Oct. 6. The B-1 has four F-101 engines with each capable of providing more than 30,000 pounds of thrust with an afterburner. (U.S. Air Force photo/Senior Airman Corey Hook)