(CNN) -- An All Nippon Airways 787 Dreamliner was held in Tokyo after a mechanical problem, the fourth such incident for Dreamliners in 10 days. The plane was delayed Thursday after a cockpit message indicated a problem with the power supply to its air-conditioning system. More than 100 passengers who were supposed to fly to Frankfurt departed on a different plane eight hours after the scheduled departure time, ANA said. Earlier this week, a Denver-bound United Airlines Dreamliner was diverted back to Houston after a problem with its brake indicator. A week before, two United Dreamliners made unscheduled landings.
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A Boeing Dreamliner is held in Tokyo after problem with power supply
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Problem is fourth mechanical incident for a Dreamliner in 10 days
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On Monday, issue with brake indicator diverted plane
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Boeing: "We know it will continue to receive heightened attention."
The entire global fleet of 50 @placeholder was grounded in January after two battery overheating incidents triggered concerns among safety officials.