Former Air Force flight surgeon took HCA, nation's largest hospital operator, private with Bain Capital, KKR and Merrill Lynch in 2006. At the time the $33 billion leveraged buyout was the largest in history; eclipsed by $45 billion purchase of power giant TXU 4 months later. "Being private in these times is a blessing. The timing couldn't have been better." Founded Hospital Corp. of America with father and Jack Massey 1968; took public following year. Led management buyout 1989; took public again 3 years later. Merged with Richard Rainwater's Columbia Hospital Corp.; stepped down 1994, became chief exec again 3 years later. Nashville native now focused on philanthropy through family foundation.