United Airlines executives know few things frustrate customers as much as not knowing why their flights are delayed, so starting Monday it plans to test a new system in Phoenix and Houston that'll tell passengers far more about their late flight than they ever expected to learn.

It's a program called, "Every Flight Has a Story," designed to help the airline better communicate with passengers about delays. Between Monday and Feb. 16, customers delayed at least an hour in Phoenix and Houston will receive unusually detailed information via text, email and the airline's mobile app telling them why United delayed their flight, according to information shared this week with flight attendants. Flight attendants will receive the information five minutes before customers through a push notification sent to their mobile devices, ensuring customers will not know more than they do.

United is trying the approach as it tests new ways to reduce traveler anxiety and stress. Often, the airline suspects, customers get nervous because they don't know what's happening, and they lack control. United usually gives passengers vague reasons for why their flight is late, such as "delayed due to aircraft maintenance."

"We have situations where our customers are super-frustrated because we can't tell them what's going on-a maintenance delay, weather, or rolling delays," Scott Kirby, United's president, told employees at a town hall meeting last year in Los Angeles. "They're frustrated with that, or they think we're lying to them."

A United spokesman did not reply to emails about the airline's "Every Flight Tells a Story" trial. However, last year Kirby outlined the basics, giving an example of a brief test the airline tried at Newark.

That day, Kirby said, United delayed many Newark flights due to weather, even though the weather in the Northeast and the Midwest was "perfectly clear." The problem was a line of thunderstorms in Virginia and the Carolinas. Planes coming from Florida needed to fly around the storms, and they landed late at Newark.

Usually, Kirby said, "we would just say weather delay, and people look out and say it's perfectly clear here, it's perfectly clear in Chicago, you're lying."

Instead, Kirby said United sent customers a picture of the thunderstorms, with a note saying, "your plane is coming from Fort Lauderdale and it has to divert around this so it is going to be late getting here."

It generally worked, Kirby said.

"No one likes a delay but at least they understand," he said. "If we can tell people what's going on, it will relieve so much stress and so much tension."