Airworthiness Directive · Amendment 39-22720 · Turbine section
General Electric Company Engines
This AD applies to General Electric Company (GE) Model GE90-110B1 and GE90-115B engines with an installed interstage high-pressure turbine (HPT) rotor seal having a part number and serial number listed in Table 1 or Table 2 of GE GE90-100 Service Bulletin (SB) 72-0908 R00, dated July 7, 2023 (GE SB 72-0908).
The FAA is correcting an airworthiness directive (AD) that published in the Federal Register. That AD applies to certain General Electric Company (GE) Model GE90-110B1 and GE90-115B engines. As published, references to the service information include a typographical error in the regulatory text of the AD. This document corrects that error in all references. In all other respects, the original document remains the same.
(1) Perform an ultrasonic inspection (USI) of the interstage HPT rotor seal in accordance with the Accomplishment Instructions, paragraph 3.B.(2), of GE SB 72-0908, as follows:
(i) Perform an initial USI before reaching the part cycles since new limit listed in Table 1 or Table 2, as applicable, of GE SB 72-0908, or within 10 flight cycles after the effective date of this AD, whichever occurs later; and
(ii) Repeat the USI thereafter within every 100 cycles or 175 cycles, as applicable, as listed in Table 1 or Table 2 of GE SB 72-0908, since the last inspection.
(2) If, during any USI required by paragraph (g)(1)(i) or (ii) of this AD, a non-serviceable indication is found, as defined in paragraph 3.B.(2)(b) of GE SB 72-0908, before further flight, remove the interstage HPT rotor seal from service.
As a terminating action to the repetitive USI required by paragraph (g)(1)(i) or (ii) of this AD, at the next engine shop visit after the effective date of this AD, remove the affected interstage HPT rotor seal from service.
For the purpose of this AD, an “engine shop visit” is the induction of an engine into the shop for maintenance involving the separation of pairs of major mating engine case flanges, except separation of engine flanges solely for the purposes of transportation of the engine without subsequent maintenance, which does not constitute an engine shop visit.
