Airworthiness Directive · Amendment 39-18854 · Engine compressor section
General Electric Company Turbofan Engines
This AD applies to General Electric Company (GE) GE90-76B, GE90-77B, GE90-85B, GE90-90B, and GE90-94B turbofan engines with a high-pressure compressor (HPC) stage 8-10 spool, part numbers (P/Ns) 1694M80G04, 1844M90G01, or 1844M90G02, installed.
We are superseding Airworthiness Directive (AD) 2016-13-05 for all General Electric Company (GE) GE90-76B, GE90-77B, GE90-85B, GE90- 90B, and GE90-94B turbofan engines. AD 2016-13-05 required eddy current inspection (ECI) of the high-pressure compressor (HPC) stage 8-10 spool at each shop visit for all affected engines and ECI or ultrasonic inspection (USI) for certain affected engines. This new AD requires initial and repetitive on-wing USIs of the HPC stage 8-10 spool for certain engines prior to shop visit and ECI of all affected engines at each shop visit. This AD was prompted by analysis that the risk of the failure of an HPC stage 8-10 spool was excessive without repetitive USI prior to shop visit. We are issuing this AD to correct the unsafe condition on these products.
(1) For HPC stage 8-10 spool, P/N 1694M80G04, all serial numbers (S/Ns), or HPC stage 8-10 spool, P/N 1844M90G01 or 1844M90G02, with a S/N listed in Figure 1 to paragraph (f) of this AD; perform an on-wing ultrasonic inspection (USI) of the stage 8 aft web upper face as follows:
(i) Perform an initial USI after reaching 8,000 cycles since new (CSN), but, before exceeding 9,000 CSN, or within 500 cycles in service after July 29, 2016, whichever occurs later.
(ii) Thereafter, perform a USI of the stage 8 aft web upper face every 500 cycles since last inspection.
(iii) Compliance with paragraph (f)(2)(i) or (f)(2)(iii) of this AD is terminating action for the initial and repetitive USIs specified by paragraphs (f)(1)(i) and (ii) of this AD.
| Part Nos. | Serial Nos. | ||||
| 1844M90G01 | GWN005MF | GWNBK753 | GWNBS077 | GWNBS497 | GWNBS724 |
| GWN005MG | GWNBK754 | GWNBS078 | GWNBS499 | GWNBS794 | |
| GWN0087M | GWNBK841 | GWNBS079 | GWNBS500 | GWNBS810 | |
| GWN0087N | GWNBK842 | GWNBS080 | GWNBS501 | GWNBS811 | |
| GWN00DGK | GWNBK843 | GWNBS081 | GWNBS502 | GWNBS812 | |
| GWN00DGL | GWNBK844 | GWNBS157 | GWNBS609 | GWNBS813 | |
| GWNBJ992 | GWNBK952 | GWNBS158 | GWNBS610 | GWNBS814 | |
| GWNBK667 | GWNBK953 | GWNBS159 | GWNBS611 | GWNBS910 | |
| GWNBK674 | GWNBK954 | GWNBS160 | GWNBS612 | GWNBS911 | |
| GWNBK675 | GWNBK955 | GWNBS266 | GWNBS613 | GWNBS912 | |
| GWNBK743 | GWNBK956 | GWNBS267 | GWNBS614 | GWNBS914 | |
| GWNBK744 | GWNBK957 | GWNBS268 | GWNBS721 | GWNBS915 | |
| GWNBK751 | GWNBK958 | GWNBS269 | GWNBS722 | GWNBS982 | |
| GWNBK752 | GWNBK959 | GWNBS270 | GWNBS723 | GWNBS983 | |
| 1844M90G02 | GWN00C2T | GWN01C5N | GWN02N8D | GWN03RTM | GWN04E21 |
| GWN00C2V | GWN01GE2 | GWN02T3R | GWN03RTP | GWN04GHT | |
| GWN00G2N | GWN01GE3 | GWN02WGM | GWN040RL | GWN04GHW | |
| GWN00G2P | GWN01GE4 | GWN0311K | GWN040RM | GWN04GJ0 | |
| GWN00PFP | GWN01GE6 | GWN035PP | GWN040RN | GWN04JW6 | |
| GWN00PFR | GWN01WH1 | GWN038TD | GWN040RP | GWN04JW7 | |
| GWN00T2N | GWN02688 | GWN039TG | GWN04202 | GWN04JW8 | |
| GWN00YHV | GWN02689 | GWN03G2R | GWN0435W | GWN04L7K | |
| GWN0125G | GWN0268A | GWN03G2W | GWN04360 | GWN04L7L | |
| GWN0125H | GWN02DP2 | GWN03G30 | GWN04361 | GWN04MT7 | |
| GWN0166K | GWN02DP3 | GWN03JPC | GWN04362 | GWN04MT8 | |
| GWN01C5K | GWN02F9F | GWN03JPD | GWN04ATG | GWNBS984 | |
| GWN01C5L | GWN02F9G | GWN03N8P | GWN04ATH | ||
| GWN01C5M | GWN02L9T | GWN03N8R | GWN04E20 |
(2) For all HPC stage 8-10 spools, P/N 1694M80G04, 1844M90G01, or 1844M90G02, perform an eddy current inspection (ECI) of the stage 8 aft upper face as follows:
(i) Perform an initial ECI of the stage 8 aft web upper face at the next shop visit after the effective date of this AD.
(ii) Thereafter, perform an ECI of the stage 8 aft web upper face at each subsequent shop visit.
(iii) If you performed an ECI of the stage 8 aft web upper surface before the effective date of the AD, you met the requirements of paragraph (f)(2)(i) of this AD.
(3) Remove from service any HPC stage 8-10 spool that fails the inspection required by paragraphs (f)(1) or (2) of this AD, and replace with a spool eligible for installation.
For the purpose of this AD, an engine shop visit is the induction of an engine into the shop for maintenance during which the compressor discharge pressure seal face is exposed.
