Airworthiness Directive · Amendment 39-16135 · General Electric Company GE90-110B1, GE90-113B, and GE90-115B Series Turbofan Engines
General Electric Company GE90-110B1, GE90-113B, and GE90-115B Series Turbofan Engines
This AD applies to General Electric Company (GE) GE90-110B1, GE90-113B, and GE90-115B series turbofan engines with stage 6 low-pressure turbine (LPT) blades, part number (P/N) 1765M37P03 or P/N 1765M37P04, installed. These engines are installed on, but not limited to, Boeing 777-200LR, 777-300ER, and 777 Freighter series airplanes.
The FAA is adopting a new airworthiness directive (AD) for General Electric Company (GE) GE90-110B1, GE90-113B, and GE90-115B series turbofan engines with stage 6 low-pressure turbine (LPT) blades, part number (P/N) 1765M37P03 or P/N 1765M37P04, installed. This AD requires initial and repetitive inspections for shroud interlock wear of the stage 6 LPT blades. This AD also requires replacing those blades with stage 6 LPT blades eligible for installation at the next engine shop visit as terminating action to the repetitive blade inspections. This AD results from eight reports of GE90-115B stage 6 LPT single-blade separation events. We are issuing this AD to prevent failure of stage 6 LPT blades, which could result in uncontained engine failure and damage to the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Before accumulating 3,000 engine operating hours time-since-new, or 400 engine cycles-since-new, whichever occurs first, inspect the stage 6 LPT blades, P/N 1765M37P03 or P/N 1765M37P04 for shroud interlock wear. Thereafter, re-inspect within every 1,000 engine operating hours, or within 125 engine cycles-since-last inspection, whichever occurs first. Use paragraphs 3.A. through 3.A.(2)(g)(12) of the Accomplishment Instructions of GE Service Bulletin (SB) No. GE90-100 SB 72-0260, Revision 7, dated June 2, 2009, to do both the initial and repetitive inspections.
At the next engine shop visit, replace the stage 6 LPT blades, P/N 1765M37P03 or P/N 1765M37P04, with stage 6 LPT blades eligible for installation as terminating action to the repetitive inspections required by this AD.
After the effective date of this AD, do not install any stage 6 LPT blades, P/N 1765M37P03 or P/N 1765M37P04, onto any engine.
(i) An inspection performed before the effective date of this AD using GE SB No. GE90-100 SB 72-0260, Revision 4, dated October 8, 2008, or Revision 5, dated November 7, 2008, or Revision 6, dated May 1, 2009, satisfies the initial inspection requirement of this AD.
For the purpose of this AD, an engine shop visit is induction of the engine into the shop for any cause.
