Travelers got a stumbling start on holiday travel as a glitch in a Federal Aviation Administration computer caused flight cancellations and delays across the nation Thursday.
By late afternoon, some 112 flights in and out of Tampa International — nearly one in four — were delayed or expected to arrive at least 15 minutes behind schedule, according to the flight-tracking site FlightStats.com.
The snarl — traced to something as simple as a single circuit board — prompted calls for more money and manpower at the Federal Aviation Administration, which has struggled without success for years to overhaul the air traffic system.
The circuit board, at an FAA center in Salt Lake City, is part of a multibillion-dollar nationwide communications network that the agency has spent years installing as part of plans to modernize air traffic control.
A government watchdog said last year that the network was over budget and plagued by outages. On a single day in 2007 alone, the failure of parts of the network was responsible for 566 flight delays.
Aviation experts are unsure whether any system that relies on the interconnectedness of computers can prevent glitches from causing havoc unless there are sufficient backup systems to handle the thousands of flight plans filed each day in the United States.
"A good communications system should have enough redundancy that a failure shouldn't hurt it that badly," said Michael Ball, a University of Maryland professor who specializes in aviation operations research.
Lawmakers in Washington pounced. Sen. Charles Schumer, D-N.Y., said that the country's aviation system is "in shambles" and that the FAA needs more resources to prevent similar problems in the future.
"If we don't deliver the resources, manpower and technology (to) the FAA it needs to upgrade the system, these technical glitches that cause cascading delays and chaos across the country are going to become a very regular occurrence," he said in a statement.
Sen. Byron Dorgan, D-N.D., chairman of the Senate's aviation panel, said he plans to grill FAA administrator Randy Babbitt about the issue at a Dec. 10 hearing. Rep. Jerry Costello, D-Ill., chairman of the House aviation panel, said he has asked the transportation inspector general to investigate and report to Congress within 60 days.
It was just a year and three months ago that the FAA had to deal with a similar headache. In August 2008, a software malfunction delayed hundreds of flights around the country.
In that episode, the Northeast was hit hardest by the delays, caused by a glitch at the Hampton, Ga., facility that processes flight plans for the eastern United States.
FAA officials and an official for the union that represents the agency's technicians said Thursday's failure prevented air traffic control computers in different regions of the country from sending each other information about flights going back and forth.
The two large computer centers — in Salt Lake City and Hampton, an Atlanta suburb — were both affected, as were 21 regional radar centers around the country.
The problem began with the failure of a single small circuit board inside a router.
Air traffic controllers were forced to type in complicated flight plans themselves because they could not be transferred automatically from computers in one region of the country to computers in another, slowing the whole system.
Most of the local delays were tolerable, around 30 or 45 minutes. But as delays cascaded through the day, a handful of planes ran two, three and even four hours off schedule.
Early morning travelers on flights leaving Tampa International hit the most delays. From 7 a.m. through 8:45 a.m., half the 37 local departures left behind schedule, arrived at their destinations late or both.
Hartsfield Jackson Atlanta International Airport, the world's busies, was particularly affected. The airport also is a hub for Delta Air Lines and AirTran Airways.
Bad weather on the East Coast made the situation worse, tying up Philadelphia, Newark and all three Washington, D.C., area airports.
Local Delta flights to Atlanta and Cincinnati ran two hours late through the morning, said Brenda Geoghagan, spokeswoman for Tampa International.
Among those waiting out delays was Larry Russoniello, who raises horses in Ocala. He was scheduled to fly Delta to Lexington, Ky., through Cincinnati at 11:30 a.m., but the departure was delayed until 2:30 p.m.
He worried about missing a horse sale that would end at 7 p.m. "I'm going to get some drinks,'' he said.
Times staff writers Steve Huettel, Andy Boyle and Michael Van Sickler contributed to this report, which also includes information from the Associated Press.