Heavyweight unification series Heavyweight unification series The heavyweight unification series, also known as the Heavyweight World Series, was a sequence of professional boxing matches held in 1986 and 1987 to crown an undisputed champion of the heavyweight class. The series was produced by HBO Sports and promoted by Don King. It ended with Mike Tyson as undisputed champion, holding the championship belts of the International Boxing Federation, World Boxing Association, and World Boxing Council. Prior to the series, the last undisputed heavyweight champion had been Leon Spinks, who won the championship in his 1978 victory over Muhammad Ali. Spinks had been stripped of
McDonnell Douglas DC-10 Extender, are based on the -30 models. Production of the DC-10 ended in 1989, with 386 delivered to airlines and 60 to the U.S. Air Force. The DC-10 was succeeded by the related McDonnell Douglas MD-11, essentially an enlarged version of the DC-10 with a number of detail improvements. Boeing, which merged with McDonnell Douglas in 1997, conducted an upgrade program that equipped many in-service DC-10s with a glass cockpit that eliminated the flight engineer position; the upgraded aircraft were re-designated as MD-10s. The DC-10's last commercial passenger flight took place in February 2014, although freighter versions continue to operate.