American Airlines canceled almost 1,100 flights, or nearly half its schedule, on Wednesday to reinspect aircraft, a disruption that affected about 100,000 passengers and triggered chaos at the busiest US airports.

The airline said it expects about 900 cancellations yesterday.

The disruption at the No 1 domestic airline, a unit of AMR Corp, follows 460 cancellations on Tuesday and hundreds of cancellations two weeks ago. The March disruption was for the same reason as this week's problem - to ensure compliance with a Federal Aviation Administration (FAA) safety directive on wiring inspections for MD-80 aircraft.