(CNN) -- A United Airlines 787 Dreamliner was diverted due to a mechanical problem, the third such incident for Dreamliners in six days.
United Flight 94 was on its way to Denver early Sunday when it was forced to fly back to the Houston airport where the flight had originated, United Airlines said.
The cause: an issue with the brake indicator.
The plane landed without incident and with no passenger injuries, said Boeing, which makes the Dreamliner.
On Tuesday, another United Airlines Dreamliner flight made an unscheduled landing.
That flight was on its way from Denver to Tokyo, when it was diverted to Seattle because of an indicated problem with its oil filter.
On Thursday a third United 787 flight was diverted to Newark's Liberty International Airport in New Jersey, United said, due to a "low oil indication." That Dreamliner -- which was en route from London to Houston, also landed safely.
The incidents come six months after the Federal Aviation Administration and other officials grounded the Dreamliner worldwide due to troubles with its battery system.
"The 787 is a great airplane and we know it will continue to receive heightened attention when reliability events occur in service," Boeing spokeswoman Yvonne Leach said Sunday.
The 787 Dreamliner began service in the U.S. in 2012.
The entire global fleet of 50 Dreamliners was grounded in January after two battery overheating incidents triggered concerns among safety officials.
Among the Dreamliner's innovative new designs is a battery system that uses new, lighter lithium-ion batteries.
In April, the FAA ordered all 787 operators to make specific modifications. United has been flying its fleet of six 787s since May 20.
United is the sole domestic operator of the airplane, which boasts high fuel efficiency due to the light-weight carbon-composite materials used in its wings and fuselage.
In an apparent show of confidence in the new airliner, United announced Tuesday it is ordering 20 additional Dreamliners, specifically the 787-10 model, which is a longer version of the plane.
The plane represents a new generation of efficient wide-body, long-range airliners, helping to make it among the world's most watched aircraft.
Airlines worldwide have committed to buy the plane, and hundreds of millions of dollars are riding on Dreamliner's success. Boeing's rival Airbus flew a similar airliner, its highly anticipated A350 XWB, for the first time on June 14 at its facility in Toulouse, France.
CNN's Thom Patterson contributed to this report