Minneapolis ? Northwest Airlines Corp. said it was able to fly its full schedule Wednesday after its computer system resumed normal operations.

Northwest said 277 of its 1,373 flights on Wednesday were delayed an average of 12 minutes before technicians fixed the system. On Tuesday, about 285 departures were delayed an average of 21 minutes as result of the computer problem, spokesman Kurt Ebenhoch said.

Backup systems were used while technicians worked on the problem.

Ebenhoch said Detroit was the most seriously affected of its three U.S. hubs. Minneapolis-St. Paul and Memphis, Tenn., experienced fewer delays. The departure delays included international flights.

The airline issued a waiver allowing customers to change their travel plans without penalty. Customers with confirmed tickets for travel scheduled Tuesday and Wednesday may reschedule their travel to begin on or before Aug. 1 without penalty or administrative fees.