ANA ANA.L (9202.T) last month grounded five of its 11 Dreamliners after tests revealed a risk of engine corrosion. The glitch was the latest disruption to Boeing's (BA.N) flagship jet as the Chicago-based company recovers from a series of production delays.

"We have solved the problem by changing engine parts. All the planes are back in operation," ANA Chief Financial Officer Kiyoshi Tonomoto told reporters on Friday.

The Trent 1000 engines on the ANA planes were supplied by Rolls-Royce (RR.L). ANA launched Dreamliner, the world's first passenger jet built mainly from lightweight carbon fibre, in October last year.

Japan Airlines, which has four 787s in its fleet, uses engines built by GE and therefore does not face problems similar to those that affected ANA.

The grounding of ANA's five Dreamliners is but one of several problems. In November, the carrier reported a landing gear problem weeks after taking delivery of the first $194 million Dreamliner.

On the aircraft's electronic dimmable windows, ANA said it is not seeing any problems.

Boeing is still studying how to improve the windows, but ANA clients have not complained about the lighting in the cabin, said Ryosei Nomura, an ANA spokesman. (Reporting by Junko Fujita; Editing by Ryan Woo)

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