The Boeing B-47 was the country's first swept-wing multi-engine bomber. It represented a milestone in aviation history and a revolution in aircraft design. Every large jet aircraft today is a descendant of the B-47. Because early jet engines could not provide enough thrust for takeoff, the prototype XB-47 had 18 small rocket units in the fuselage for jet-assisted takeoff (JATO). Thrust reversers and anti-skid brakes had not yet been developed, so a ribbon-type drag parachute reduced the B-47 landing speed.