The crash killed 49 people — everyone on board except first officer James Polehinke, who was in critical condition Tuesday.
The jet stuggled to get airborne and crashed in a field after taking off Sunday from a 3,500-foot runway instead of an adjoining one that was twice as long. Experts said the plane needed at least 5,000 feet for takeoff.
The air traffic controller had an unobstructed view of the runways and had cleared the aircraft for takeoff from the longer runway, said National Transportation Safety Board member Debbie Hersman.
Then, "he turned his back to perform administrative duties," Hersman said. "At that point, he was doing a traffic count."
Earlier Tuesday, the Federal Aviation Administration acknowledged violating its owns policies when it assigned only one controller to the airport tower that morning. The policy is outlined in a 2005 directive requiring that control tower observations and radar approach operations be handled separately.
CBS News correspondent Bob Orr reports that the cockpit voice recorder and air traffic control tapes leave no doubt the pilots were lost on the wrong runway. Flight 5191 was cleared to take off on runway 22, a lighted and long 7,000-foot strip. But for some reason, the pilots turned onto the shorter and unlighted runway 26.
FAA spokeswoman Laura Brown said the controller had to do his own job — keeping track of airplanes on the ground and in the air up to a few miles away — as well as radar duties.
The controller had been working at the Lexington airport for 17 years and was fully qualified, Hersman said.
Polehinke was flying the plane, but it was the flight's captain, Jeffrey Clay, who taxied the aircraft onto the wrong runway, Hersman said. Clay then turned over the controls to Polehinke for takeoff, the investigator said.
Polehinke was pulled from the burning plane after the crash but has not been able to tell investigators why the pilots tried to take off from the wrong runway.
Both crew members were familiar with the Lexington airport, according to Hersman. She said Clay had been there six times in the past two years, and Polehinke had been there 10 times in the past two years — but neither had been to the airport since a taxiway repaving project just a week earlier that had altered the taxiway route.