152 Alaskan Airlines and Horizon Air flights were cancelled yesterday because of a computer outage, but as of today they are back up and flights have resumed.

The computer outage was caused by a transformer that blew and took out Alaska Airlines’ and Horizon Air’s central computers, which are used in flight planning, according to Alaska Airlines President Brad Tilden. At least 12,000 passengers were reported to be affected by the outage.

Tilden and Horizon Air president Glenn Johnson posted a YouTube video, apologizing for the outage and related delays and cancellations.

As of Sunday, the computer systems are reported to be fixed and working, though passengers were still being asked to check flight status before heading to the airport, and the Alaskan Airlines website reports that some flights may still be affected by delays.

According to Alaskan Airlines, affected passengers may reschedule flights without incurring standard change fees if the flights are rescheduled before March 28, for travel on or before March 31, 2011. However, they warn that rescheduled flights may have higher fares. They are also offering full refunds if the consumer decides not to travel.

Affected customers are being asked to reschedule their flights through alaskaair.com, or by calling 1-800-252-7522 for flights on Alaska Air, or 1-800-547-9308 for flights on Horizon Air.