Boeing Co. urged operators of 787 Dreamliners and the newest 747 models that are powered by General Electric Co. GE engines to avoid high-altitude thunderstorms, which can cause engine malfunctions.

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Boeing's warning prompted Japan Airlines Co. 9201.TO -0.57% to replace 787 Dreamliners on routes linking Tokyo with New Delhi and Singapore and to drop plans for using 787s between Tokyo and Sydney.

There have been six icing-related incidents with GEnx engines since April, most recently early this month, affecting five 747s and one 787.

GE has said that the aircraft that experienced engine issues landed safely at their destinations and that in every case, the engines resumed normal thrust.

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JAL said its 787s would continue on other routes where they are less likely to encounter the high-altitude storms that can cause tiny ice crystals to build up inside engines. The airline's statement also suggested that it is likely to seek financial penalties from Boeing and GE.