Airworthiness Directive · Amendment 39-19548 · Turbine section
General Electric Company Turbofan Engines
This AD applies to General Electric Company (GE) GEnx-1B54, -1B58, -1B64, -1B67, -1B70, -1B54/P1, -1B58/P1, -1B64/P1, -1B67/P1, -1B70/P1, -1B54/P2, -1B58/P2, -1B64/P2, -1B67/P2, -1B70/P2, -1B70C/P1, -1B70/72/P1, -1B70/75/P1, -1B74/75/P1, -1B75/P1, -1B70C/P2, -1B70/72/P2, -1B70/75/P2, -1B74/75/P2, -1B75/P2, -1B76/P2, -1B76A/P2, -1B78/P2, -2B67, -2B67B, and -2B67/P turbofan engines with a high-pressure turbine (HPT) stator case (HPT case), part number (P/N) 2302M90G04 installed, and with any serial number (S/N) listed in Table 1, 2, or 3, in the Planning Information section of GE Service Bulletin (SB) GEnx-2B S/B 72-0360, Revision 04, dated December 4, 2018, or GE SB GEnx-1B S/B 72-0424, Revision 04, dated December 3, 2018, installed.
We are superseding Airworthiness Directive (AD) 2018-16-07, which applied to certain General Electric Company (GE) GEnx turbofan engines. AD 2018-16-07 required removal and replacement of affected high-pressure turbine (HPT) stator cases (HPT cases). This AD retains those requirements, but reduces certain compliance times. This AD was prompted by the discovery of a quality escape at a manufacturing facility and a determination that the compliance time for the removal and replacement of certain HPT cases must be reduced. We are issuing this AD to address the unsafe condition on these products.
(1) For HPT cases listed in Planning Information, Table 1 or 2, of GE SB GEnx-2B S/B 72-0360, Revision 04, dated December 4, 2018, or GE SB GEnx-1B S/B 72-0424, Revision 04, dated December 3, 2018, determine the lesser of the following: Cycles since new (CSN) or cycles since Class A fluorescent penetrant inspection (CSFPI) of the entire HPT case.
(2) Using the determination made in paragraph (g)(1) of this AD, remove from service the HPT case before exceeding the applicable cycles in service accrued after August 15, 2018, the effective date of AD 2018-16-07, as specified in Table 1 to paragraph (g)(2) of this AD. Replace the removed HPT case with a part eligible for installation.
(3) For HPT cases listed in Planning Information, Table 3, of GE SB GEnx-2B S/B 72-0360, Revision 04, dated December 4, 2018, determine the lesser of the following: CSN or CSFPI of the entire HPT case.
(4) Using the determination made in paragraph (g)(3) of this AD, remove from service the HPT case before exceeding the cycles in service specified in Table 2 to paragraph (g)(4) of this AD. Replace the removed HPT case with a part eligible for installation.
(5) For HPT cases listed in Planning Information, Table 3, of GE SB GEnx-1B S/B 72-0424, Revision 04, dated December 3, 2018, determine the lesser of the following: CSN or CSFPI of the entire HPT case.
(6) Using the determination made in paragraph (g)(5) of this AD, remove from service the HPT case before exceeding the cycles in service specified in Table 3 to paragraph (g)(6) of this AD. Replace the removed HPT case with a part eligible for installation.
After the effective date of this AD, do not install any affected HPT case onto any engine if the HPT case has been disassembled to piece-part level. Affected HPT cases are identified in paragraphs (g)(1), (g)(3), and (g)(5) of this AD. Piece-part level is defined as when the part is completely disassembled.
