LEXINGTON, Ky. (AP) -- The lone air traffic controller on duty the morning Comair Flight 5191 crashed had only two hours of sleep before starting work on the overnight shift, a federal investigator said Wednesday.
National Transportation Safety Board member Debbie Hersman said the controller had only nine hours off between work shifts Saturday. That was just enough to meet federal rules, which require a minimum of eight hours off between shifts, Hersman said.
The controller, a 17-year veteran whose name has not been released publicly, worked from 6:30 a.m. to 2:30 p.m. on Saturday. He came back to work at 11:30 p.m. on the same day to begin an eight-hour overnight shift.
The commuter jet crashed on Sunday morning, in the final hours of the controller's shift, while trying to take off from Blue Grass Airport.
Federal officials have been looking for explanations for why Flight 5191 mistakenly tried to take off from a runway that was too short, crashing in a nearby field and killing 49 of 50 people on board.
The crash threw a spotlight on another practice aviation experts say goes on around the country: Small regional airports are sometimes manned by a single air traffic controller, even though federal rules require two.
The Federal Aviation Administration has directed Blue Grass Airport and others like it to staff their towers with at least two controllers. But the FAA has acknowledged that only one was working Sunday in Lexington during the crash.
In a policy outlined in a directive last November, the FAA said two controllers must be on duty for all shifts at any airport that handles both control tower observations and radar operations.
But Ken Spirito, director of a regional airport in Peoria, Ill., said it's common for some late-night and early morning shifts to be staffed with only one controller. Someone may call in sick or take a vacation, and the FAA usually decides to keep the airport open, he said.
"The mandate that is issued by FAA is only as good as the staffing levels at that particular tower," Spirito said.
FAA spokeswoman Laura Brown said that at the time of the accident, there were only two other towers -- in Duluth, Minn., and Fargo, N.D. -- that were not following the policy to staff with two controllers.
"We have clarified the guidance for them," Brown said.
She said staffing was adjusted at four other towers earlier this month, before the Comair crash. "This is an issue we've been looking at," she said.
Scott Zoeckler, who worked as a controller at Blue Grass for 25 years before retiring in 2004, said the overnight and early morning shifts were usually manned by only one person.
On Sunday, the controller on duty at the Lexington airport had turned his back to perform some "administrative duties" when the plane veered onto the wrong runway, investigators said.
The crash's only survivor, first officer James Polehinke, who was flying the plane when it crashed, remained hospitalized Wednesday in critical condition.
Jed Doty, a Louisville flight instructor who also flew briefly for Comair last year, said it is the pilot's duty to get on the right runway.
"It's your responsibility to immediately speak up because, especially in busy airports, you can get in some pretty bad situations pretty quickly," Doty said.
On Wednesday, six tour buses took the victims' families to the crash site for the first time. The airport also established a memorial in a parking lot, featuring a banner reading "Remembering 5191" with pens for people to write messages.
Law firms lined up to represent family members who want to sue for negligence. One Fort Worth, Texas, firm published a full-page ad in Wednesday's Lexington Herald-Leader promising families it would seek "the greatest amount of damages allowed by law."
Comair offered to pay $25,000 per passenger to each family who lost a loved one.
Comair spokeswoman Kate Marx would not say how many families had requested the payment, which she said "in no way prejudices their right to any claim they may have under the applicable law."