The carrier said the additional inspections are based on Federal Aviation Administration audits involving technical compliance issues. As many as 500 flights were canceled Tuesday, with additional cancellations likely Wednesday.

Nine inbound and 9 outbound flights were dropped from the schedule at San Francisco International. In addition, 5 flights at San Jose Mineta International and one at Oakland airport were cancelled.

American tried to put affected passengers on other flights. It instructed travelers to check AA.com or with travel agents about a flight's status.

Several major airlines have grounded planes in recent weeks amid tighter FAA oversight.

(clo)