A Fayette County grand jury has returned felony theft indictments against four former managers of Lexington's Blue Grass Airport, following an investigation into questionable spending practices.All four resigned this year after an investigation by the Lexington Herald-Leader reported that some airport leaders had spent more than $500,000 on travel, meals, entertainment and gifts.Those charged include Mike Gobb, the airport's former executive director, and former airport managers John P. Slone, John Coon and John Rhodes.All four were forced to resign following the newspaper report early this year.Arraignment is scheduled for October 30.