AD NUMBER: 2020-01-55

PRODUCT: Certain General Electric Company (GE) GE90-110B1 and GE90-115B model turbofan engines.

ACTION: Final rule; request for comments.

SUMMARY: This AD was sent previously as an emergency AD to all known U.S. owners and operators of the GE GE90-110B1 and GE90- 115B model turbofan engines with certain engine serial numbers.

This AD requires the removal from service of the interstage seal, part number 2505M72P01 or 2448M33P01, from the affected engines. This AD was prompted by a recent event involving an uncontained high-pressure turbine (HPT) failure that resulted in an aborted takeoff.

DATES: This AD is effective March 2, 2020 to all persons except those persons to whom it was made immediately effective by Emergency AD 2020-01-55, issued on January 17, 2020, which contained the requirements of this amendment. The FAA must receive comments on this AD by March 30, 2020.

COST: The FAA estimates that this AD affects 0 engines of U.S. registry. Operators may incur the following costs in order to comply with this AD:

Remove interstage seal

• Labor: 100 work-hours × $85 per hour = $8,500
• Parts: $509,600
• Cost per engine: $518,100

FMI: AD