After an equipment glitch by a Federal Aviation Administration (FAA) contractor caused a nationwide wave of flight cancellations and delays Thursday, lawmakers are asking the inspector general responsible for the agency to fast-track a review of the problem.

The systemwide delays were caused by the failure of a router maintained by Harris Corp. at a center in Salt Lake City. Harris maintains and operates the technology that FAA facilities use to communicate nationwide.

The failure did not affect radar or the ability of air traffic controllers to communicate with flights that were airborne, but it did affect airline flight plans, which are automated. During the outage, the plans had to be entered manually, significantly slowing air transportation.

Jerry F. Costello, D-Ill., chairman of the House Transportation and Infrastructure Subcommittee on Aviation, said the incident could have been "much worse." But, he said, it still raises troubling questions, such as why Harris took four hours to diagnose the problem.

"Is the FAA's oversight of its contract with the Harris Corporation sufficient?" Costello said in a statement that listed his questions to the Transportation Department's inspector general. "The relationship between the FAA and its vendors is a critical one, given that the transition to the Next Generation Air Transportation System will require more such partnerships."

Costello and Transportation Chairman James L. Oberstar, D-Minn., asked the inspector general to report back within two months.