Reports That A Second Cracked Fan Midshaft Was Discovered In A GEnx-1B Engine On A 787 Which Had Not Yet Flown

The NTSB is continuing its investigation of an incident which occurred on July 28, 2012 involving a Boeing 787-8 airplane that experienced a loss of thrust in the right engine—a General Electric (GE) GEnx-1B turbofan – during a pre-first flight, low-speed taxi test at Charleston International Airport in Charleston, South Carolina. As reported in an earlier update, the investigation found that the forward end of the fan midshaft (FMS) fractured and separated. Examination of other pre-delivery engines revealed a second GEnx-1B engine with a cracked FMS that was installed on a 787-8 airplane that had not yet flown.

The investigation is ongoing, and an initial inspection of all in-service GEnx engines has been completed. Most recently, on September 11, 2012, a Boeing 747-8F with GE GEnx-2B turbofan engines experienced a loss of power in the No. 1 engine during the takeoff roll at Shanghai Pudong International Airport, Shanghai, China. The Civil Aviation Administration of China (CAAC) is investigating this incident, and the NTSB is participating as the state of design and manufacture of the engine and aircraft. Any investigative updates regarding this incident will be provided by the CAAC.

As part the CAAC’s investigation and in relation to the NTSB’s ongoing investigation of the July 28th engine failure, preliminary findings from the examination of the Shanghai incident engine revealed that the FMS was intact and showed no indications of cracking. The examination and teardown of that engine is continuing under the direction of the CAAC.

FMI: www.ntsb.gov