About 600 Boeing 787 engines will be modified by the end of the year to correct a transfer gearbox problem suspected in several in-flight shutdowns.
About half of the affected engines have been upgraded with a redesigned pinion gear within the transfer gearbox, GE Aviation says.
Wear on the pinion gear has led to excessive vibration, ultimately causing shutdowns of the engine.
GE adds that investigators have not determined the cause of an in-flight shutdown on 7 August by a GEnx-1B-powered Jetstar 787-8.
The 787-8, registered VH-VKK, diverted to Guam, according to the Australian Transport Safety Board.
The aircraft entered service on 16 July 2015, according to the Flight Fleet Analyzer database.
The redesign of the pinion is the second on-going service bulletin on the GEnx-1B engine.
Earlier this year, the US Federal Aviation Administration also directed airlines to modify the tip clearances for the fan blades. Otherwise, the blades can rub against the case in some cases due to ice shedding.
About 80% of the installed GEnx-1B fleet has completed the tip clearance modification, GE says.
Source: Cirium Dashboard
