GE says that as of July 18, the suspect fleet of engines still flying had been reduced to 29. “With the ones completed, either the entire gearbox was replaced or a couple of the suspect gears in the transfer gearbox were replaced with ones that were shot-peened,” says the engine maker. The extent of the refurbishment task remains large, as there are now many other engines to replenish on the production line and in maintenance and repair shops. GE is also expected to issue a service bulletin shortly, requiring all suspect transfer gearboxes to be removed from service by late September.
The Korea Aviation and Railway Accident Investigation Board delegated the investigation of the July 2 inflight shutdown to the U.S. NTSB, which is working with GE and the FAA to determine the root cause. GE says the “final probable cause” for the July 2 event will be determined by the NTSB.