Boeing is alerting airlines about possible engine icing problems on some of its new planes. It is recommending that planes with a specific General Electric engine avoid flying near thunderstorms that might contain ice crystals.

Boeing says it issued the advisory after ice crystal formation in some instances diminished engine performance. Airlines with planes affected include United, Japan Airlines, Lufthansa and Air India. Models affected are the 747-8 and the 787, which Boeing Co. calls the Dreamliner.

Boeing recommended that affected planes fly at least 50 nautical miles (92 kilometers) from thunderstorms that may contain ice crystals.

It's the latest problem to confront the 787. Earlier this year, air safety authorities grounded the 787 after two planes suffered from smoldering batteries. Flights resumed after Boeing redesigned the battery system.