EASA SIB NE-12-26
General Electric GE90 Engines - Fan Blade Root and Blade Dovetail Inspections
Summary
The Special Airworthiness Information Bulletin SAIB: NE-12-26 provides updated inspection guidance for fan blade root and blade dovetail inspections on General Electric GE90-76, GE90-85, GE90-90, and GE90-94B series turbofan engines installed on Boeing 777 aircraft. This bulletin informs operators and maintenance personnel about focused inspections to detect delaminations in the fan blade dovetail area. The document clarifies that the issue does not constitute an unsafe condition requiring mandatory regulatory action.
What Changed
SAIB NE-12-26 updates the Boeing 777 Aircraft Maintenance Manual (AMM) to include clearer descriptions and focused inspections for fan blade root delaminations. It introduces service limits allowing some blades with dovetail delaminations to remain or return to service, which was previously prohibited. These changes are reflected in AMM Revision 61 and later, as well as in the GE90 Engine Manual updates.
Why It Matters
This bulletin helps aviation professionals correctly identify and assess fan blade dovetail delaminations, preventing unnecessary blade removals and ensuring continued engine reliability. Operators and maintenance organizations benefit from clarified inspection criteria and serviceability limits, supporting safe and cost-effective maintenance practices. Compliance with these updated inspections aids in maintaining engine performance and airworthiness without imposing mandatory directives.
What To Do
Operators and maintenance personnel should follow Boeing 777 AMM Revision 61 or later, specifically Task 72-21-02-200-801-G00 and Subtask 72-21-02-220-002-G00, to inspect fan blade roots and dovetails during piece part exposures. If delaminations are found, they must adhere to the AMM's serviceability instructions and temporary revisions. No explicit compliance deadline is stated, but adherence is recommended at each inspection opportunity.