The U.S. Federal Aviation Administration (FAA) offered few details Thursday about the exact nature of the glitch, which caused major delays and flight cancellations in airports across the country. But in a statement, the agency blamed a "software configuration problem" within the FAA Telecommunications Infrastructure (FTI) in Salt Lake City.

That problem brought down a system used mainly for traffic flow and flight planning services for about four hours this morning. The flight management system -- it's called the National Airspace Data Interchange Network (NADIN) -- was affected because it relies on FTI services to operate, the FAA said. There was no indication that the disruption was the result of a cyberattack, the FAA said.

FAA experts were investigating the outage and meeting with Harris Corp., the company that manages FTI to "discuss system corrections to prevent similar outages," the agency said.

In an e-mailed statement, a Harris spokesman said the company is working to "evaluate the interruption" to prevent future outages. "FTI has proven to be one of the most reliable and secure communications networks operating within the civilian government. Safety and security is our highest priority," the company said.

A spokeswoman for the Professional Airways Systems Specialists (PASS) union, which represents more than 11,000 FAA employees, told Computerworld the problem arose when scheduled maintenance on FTI in Los Angeles corrupted a router in Salt Lake City. A back-up router that should have kicked-in when the primary router went down failed to do so, resulting in the widespread outage, she said.