General Electric on Thursday issued its second directive this week for an inspection of its new GEnx engine on Boeing jets, this time telling airlines to check the installation of a turbine part, after an engine failed on a Boeing 747-8 freighter last month in Shanghai.
GE told GEnx operators to make sure the part, a low-pressure turbine stage-one nozzle, is installed correctly at the rear of the engine. The nozzle directs air into the rotating low-pressure turbine blades.
On Tuesday, GE had called for inspections of the low-pressure turbine itself.
On September 11, a GEnx engine in a 747-8 operated by Air Bridge Cargo in Shanghai lost thrust during take-off. The aircraft returned to the ramp and the engine was later replaced.
GE said some operators have already begun the hour-long inspection and have not discovered new issues. GE said in a statement it is not calling for repeated inspections.
Kelly Nantel, public affairs director for the National Transportation Safety Board, said damage in the affected 747-8 engine was mainly limited to the low-pressure turbine hardware, located at the back of the engine.
"Aside from some minor collateral damage, the engine hardware forward of that point doesn't exhibit any damage," she said in an interview. "Our initial findings indicate that the low-pressure turbine stage-one nozzle may have been improperly assembled."
GE said 120 GEnx engines powering Boeing 787 and 747-8 aircraft are flying daily. It said Boeing continues to deliver aircraft powered by these engines.
"GE continually monitors and analyses the performance of the GEnx fleet in service, and we are not aware of operational issues that would affect the continued safe flight of aircraft powered by these engines," GE said.
The engine failure in September differs from a prior incident also involving the GEnx in July.
In that instance, a cracked fan shaft was found to have caused a GEnx engine failure in a 787 in Charleston, South Carolina.
Neither engine failure has resulted in injuries. However, the chief executive of Qatar Airways said the airline would not accept delivery of 60 ordered 787s until the engines are modified.
GE on Thursday said it has finished ultrasonic inspections of the fan shaft in all of the GEnx engines now in use in 787 and 747-8 aircraft, without finding more problems.
The US Federal Aviation Administration calls for these inspections every 90 days.
