During the course of its investigation, the Federal Aviation Administration (FAA) discovered that tower staffing levels at Blue Grass Airport violated an internal policy as reflected in a November 16, 2005, memorandum requiring two controllers during the overnight shift: one in the tower working clearance, ground, and tower frequencies, and another, either in the tower or remotely at Indianapolis Center, working TRACON (radar). At the time of the accident, the single controller in the tower was performing both tower and radar duties. On August 30, 2006, the FAA announced that Lexington, as well as other airports with similar traffic levels, would be staffed with two controllers in the tower around the clock effective immediately.