United Airlines restarts 787 flights after grounding

United Airlines is again flying the 787, four months after smoldering batteries forced the plane to be grounded worldwide.

A United 787 flight took off from Houston on Monday morning and landed in Chicago. United will fly the 787 Dreamliner between Houston and Denver Tuesday.

United Continental Holdings Inc. has six 787s. Battery problems on planes owned by other airlines prompted the grounding. Federal authorities cleared the planes to fly again on April 19.

United plans to use its 787s on routes from Houston to other U.S. cities this week. It plans to restart international flights on June 10, including Denver's new non-stop route to Tokyo.

The Federal Aviation Administration lifted its grounding order last month, and Ethiopian Airlines resumed 787 flights on April 27.

Boeing never found the root cause of the smoldering batteries, but it has said that it believes its fix covers all possible causes.