DALLAS (AP) — American Airlines is still trying to dig out from under a blizzard of cancelled flights over the last few days. By midday Monday, American had canceled more than 350 flights. It’s the fourth straight day of major disruptions at American, which canceled more than 1,000 flights on Sunday. American hopes to fix its operation by hiring more flight attendants, pilots and reservations agents. The airline encouraged thousands of workers to quit last year when air travel collapsed during the pandemic, then was caught shorthanded when travel bounced back this year.