Most American Airlines flights delayed after tech issue [Video]

Following a brief outage that grounded all American airlines flights during one of the busiest travel periods of the year, American Airlines says it has resumed service Tuesday morning, albeit with substantial delays.American Airlines said a “vendor technology issue” was responsible for delaying all of its flights in the United States. But the company began boarding flights again at around 8 a.m. ET, and flights have since resumed, airline spokeswoman Sarah Jantz told CNN.The Allied Pilots Association, which represents the 16,000 pilots at American Airlines, said American Airlines’ Flight Operations System briefly went down Tuesday morning, which led to the delays. Known as the FOS, the system handles the airline’s operations, key to getting airplanes released for departure — including passenger boarding. American Airlines has backup flight planning tools to prevent an outage from shutting down the entire airline for extended periods of time, according to the union, which said …