Boeing and GE Address Icing Risk for GEnx Engines
Boeing and GE have warned companies operating Boeing 747-8 and 787 airliners powered by certain versions of General Electric’s GEnx engines about the risk of in-flight internal-engine icing that can reduce engine performance if aircraft wander too close to areas of significant precipitation, like thunderstorms at high altitudes. Engine models affected are the GEnx-2B on the 747-8 and the GEnx-1B on the 787 Dreamliner. Aircraft do not need to be flying in visible precipitation to be at risk, and the problem can occur even with engine anti-icing systems activated, according to the OEMs. The engine-icing issue was first reported early in October when a GE spokesman said the company had been notified of a half-dozen engine issues related to GEnx powerplants; he added that no one had been injured in any of the incidents. GE is at work on software changes to open and close the engines’ bleed-valve doors to prevent ice buildup behind the fan and to eject ice crystals before they enter the core section. While working on a permanent fix, Boeing and GE are warning pilots to circumnavigate thunderstorms by at least 50 miles, a much wider margin than normal. Based upon the new warnings, Japan Airlines decided last week to remove its 787s from service on both its Tokyo-Sydney and Tokyo-Delhi routes that cross areas of the equator where potentially large storms can develop.