Document ID: FAA-2020-0850-0009
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: General Electric Company Turbofan Engines
Posted Date: 2021-06-25T04:00Z

[Federal Register Volume 86, Number 120 (Friday, June 25, 2021)]
[Rules and Regulations]
[Pages 33494-33498]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-13424]

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0850; Project Identifier AD-2020-00288-E; 
Amendment 39-21569; AD 2021-11-07]
RIN 2120-AA64

Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain General Electric Company (GE) GEnx-1B64, 1B64/P1, -1B64/P2, -
1B67, -1B67/P1, -1B67/P2, -1B70, -1B70/75/P1, -1B70/75/P2, -1B70/P1, -
1B70/P2, -1B70C/P1, -1B70C/P2, -1B74/75/P1, -1B74/75/P2, -1B76/P2, -
1B76A/P2, -2B67, -2B67/P, and -2B67B model turbofan engines. This AD 
was prompted by a finding during an inspection by the manufacturer that 
two stages 6-10 compressor rotor spools in the high-pressure compressor 
(HPC) assembly were damaged at similar locations. Additionally, the 
manufacturer reported that certain stages 6-10 compressor rotor spool 
webs did not undergo a required fluorescent penetrant inspection (FPI) 
during production. This AD requires inspection of the stages 6-10 
compressor rotor spool and, depending on the results of the inspection, 
replacement of the stages 6-10 compressor rotor spool. The FAA is 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective July 30, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of July 30, 
2021.

ADDRESSES: For service information identified in this final rule, 
contact General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; 
phone: (513) 552-3272; email: aviation.fleetsupport@ae.ge.com; website: 
www.ge.com. You may view this service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 1200 
District Avenue, Burlington, MA 01803. For information on the 
availability of this material at the FAA, call (781) 238-7759. It is 
also available at https://www.regulations.gov by searching for and 
locating Docket No. FAA-2020-0850.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-0850; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains this final rule, any 
comments received, and other information. The address for Docket 
Operations is U.S. Department of Transportation, Docket Operations, M-
30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue 
SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Mehdi Lamnyi, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7743; fax: (781) 238-7199; email: 
Mehdi.Lamnyi@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain GE GEnx-1B and 
GEnx-2B model turbofan engines. The

[[Page 33495]]

NPRM published in the Federal Register on September 24, 2020 (85 FR 
60103). The NPRM was prompted by a report from the manufacturer that an 
inspection had found two stages 6-10 compressor rotor spools in the HPC 
assembly damaged at similar locations on the webs. The subsequent 
investigation determined that tool marks were created during the 
manufacturing process. In addition, the manufacturer also reported that 
certain stages 6-10 compressor rotor spool webs did not undergo a 
required FPI during production.
    In the NPRM, the FAA proposed to require inspection of the stages 
6-10 compressor rotor spool. Operators of certain affected GEnx-1B or 
GEnx-2B model turbofan engines have already completed acceptable 
inspections of the aft web of stage 6, stage 7, and stage 8 of the 
stages 6-10 compressor rotor spool. The FAA proposed to require 
operators of those affected engines to complete the inspection of the 
stages 6-10 compressor rotor spool no later than the next engine shop 
visit. The FAA proposed to require all other remaining affected GEnx-1B 
and GEnx-2B model turbofan engines to complete this inspection by the 
next engine shop visit, before the stages 6-10 compressor rotor spools 
accumulate 6,500 cycles since new, or before further flight if 6,500 
cycles since new has already been accumulated as of the effective date 
of this AD. Depending on the results of the inspection, the FAA 
proposed to require replacement of the stages 6-10 compressor rotor 
spool with a part eligible for installation. The FAA is issuing this AD 
to address the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from seven commenters. The commenters 
were American Airlines (American), GE Aviation, Japan Airlines, Nippon 
Cargo Airlines (NCA), the Air Line Pilots Association, International, 
United Airlines Engineering, and Boeing Commercial Airplanes. Three 
commenters supported the proposed rule without change. One commenter 
requested that the FAA add a term to the Definitions paragraph of the 
proposed rule, and use the latest version of the service information. 
Three commenters requested certain clarifications or changes to the 
Required Actions and Previous Credit sections. The following presents 
the comments received on the NPRM and the FAA's response to each 
comment.

Request To Clarify Rejectable Indication

    GE Aviation requested that the FAA define the term ``rejectable 
indication'' to avoid confusion in the event an indication is found 
during inspection. GE Aviation requested that the FAA define rejectable 
indication as an indication that does not meet the serviceable or 
repairable limits defined in the special procedure referenced in GE 
GEnx-1B Service Bulletin (SB) 72-0472 R02, dated November 5, 2020 
(GEnx-1B SB 72-0472) and GE GEnx-2B SB 72-0415 R02, dated November 5, 
2020 (GEnx-2B SB 72-0415).
    The FAA agrees to define a ``rejectable indication'' as used in 
paragraph (g)(2) of the Required Actions section of this AD and added 
the definition in paragraph (h), Definitions, of this AD.

Request To Clarify Acceptance of Reworked Parts

    American requested that the FAA clarify paragraph (g)(2) and 
paragraph (i), Credit for Previous Actions, regarding installation of 
parts that initially failed inspection with a rejectable indication but 
were later reworked and found acceptable. American stated that GE has 
been accepting parts that were reworked using GE Subtask 72-00-00-210-
012 in the GEnx-1B EM 72-00-00, Special Procedure 023, in accordance 
with approved GE Departure Recommendations.
    The FAA disagrees. Paragraph (g)(2) of this AD requires that if 
during an inspection, a stages 6-10 compressor rotor spool is found to 
have a rejectable indication, as defined in paragraph (h) of this AD, 
then the stages 6-10 compressor rotor spool must be removed from 
service. If the stages 6-10 compressor rotor spool is subsequently 
repaired or reworked, operators would need to submit an alternative 
methods of compliance (AMOC) request to the FAA to allow use of the 
repaired or reworked stages 6-10 compressor rotor spool.

Request To Revise References to Service Bulletin

    GE Aviation requested that the FAA update the specified service 
information by referencing Revision 2 of GE GEnx-1B SB 72-0472 and GE 
GEnx-2B SB 72-0415. GE noted that Revision 2 of these SBs had not been 
issued at the time of publication of the NPRM.
    The FAA agrees and has updated this AD to reference GEnx-1B SB 72-
0472 R02 and GEnx-2B SB 72-0415 R02, both dated November 5, 2020. This 
change to this AD imposes no additional burden on operators.

Request To Revise Previous Credit

    Japan Airlines requested that the FAA grant credit for the 
borescope inspection (BSI) or eddy current inspection (ECI) required by 
paragraph (g)(1) of this AD if inspections were previously performed in 
accordance with GE GEnx-1B SB 72-0472 R01, dated July 24, 2020.
    The FAA agrees and has updated paragraph (i), Credit for Previous 
Actions, to allow credit for inspections performed using GE GEnx-1B SB 
72-0472 R01, dated July 24, 2020 or GE GEnx-2B SB 72-0415 R01, dated 
July 24, 2020, as applicable.

Request for Reference Date Clarification

    NCA requested that the FAA clarify the meaning of ``previously 
undergone'' in paragraph (g)(1)(ii) of this AD. NCA commented that one 
of its engines underwent an inspection during an engine shop visit 
using GEnx-2B SB 72-0385 R02, dated July 29, 2019 and GE GEnx-2B SB 72-
0398 R00, dated October 30, 2019, before the effective date of this AD 
but after publication of GEnx-2B SB 72-0415 R01. NCA noted that the 
reference to ``previously undergone'' means that it has been 
implemented in accordance with SB in the past without any specific 
timeframe, so it is not clear if the NCA's engine can apply the no 
cycles since new (CSN) limit.
    The FAA clarified paragraph (g)(1)(i) and (ii) of this AD by 
removing the phrase ``previously undergone'' and referring instead to 
engines that have undergone inspections ``before the effective date of 
this AD.''

Change to Compliance Time

    The FAA updated Table 1 to paragraph (g)(1) of this AD by allowing 
operators 100 flight cycles to perform the inspections required by 
paragraph (g)(1) of this AD when an engine has a stages 6-10 compressor 
rotor spool with 6,400 CSN or greater as of the effective date of this 
AD. This change allows operators a grace period to complete the 
required inspections without unnecessary grounding of airplanes and 
still meets the safety intent of this AD.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes and any 
other changes described previously, this AD is adopted as proposed in 
the NPRM.

[[Page 33496]]

None of the changes will increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed GE GEnx-1B Service Bulletin (SB) 72-0472 R02, 
dated November 5, 2020 (GEnx-1B SB 72-0472) and GE GEnx-2B SB 72-0415 
R02, dated November 5, 2020 (GEnx-2B SB 72-0415).
    GEnx-1B SB 72-0472 describes procedures for performing a BSI or an 
ECI of stage 6, stage 7, and stage 8 webs, web transitions, and bore 
faces of the stages 6-10 compressor rotor spool for GEnx-1B model 
turbofan engines. GEnx-1B SB 72-0472 also provides the affected part 
and serial numbers of the stages 6-10 compressor rotor spools installed 
on GEnx-1B model turbofan engines.
    GEnx-2B SB 72-0415 describes procedures for performing a BSI or an 
ECI of stage 6, stage 7, and stage 8 webs, web transitions, and bore 
faces of the stages 6-10 compressor rotor spool for GEnx-2B model 
turbofan engines. GEnx-2B SB 72-0415 also provides the affected part 
and serial numbers of the stages 6-10 compressor rotor spools installed 
on GEnx-2B model turbofan engines.
    This service information is reasonably available because the 
interested parties have access to it through their normal course of 
business or by the means identified in ADDRESSES.

Other Related Service Information

    The FAA also reviewed Subtask 72-31-45-160-002 of TASK 72-31-45-
200-807 in GE GEnx-1B Engine Manual 05-21-00, Life Limits 001 Mandatory 
Inspections, Rev. 31 dated, January 31, 2020; and Subtask 72-31-45-160-
002 of TASK 72-31-45-200-801 in GE GEnx-2B Engine Manual 05-21-00, Life 
Limits 001 Mandatory Inspections, Rev. 24 dated, January 31, 2020. The 
Subtasks provide guidance on performing the ECI on the stages 6-10 
compressor rotor spool on GE GEnx-1B and GEnx-2B model turbofan 
engines.
    The FAA also reviewed the following GE SBs: GEnx-1B SB 72-0448 R00, 
dated July 29, 2019 (GEnx-1B SB 72-0448); GEnx-1B SB 72-0460 R00, dated 
October 30, 2019 (GEnx-1B SB 72-0460); GEnx-2B SB 72-0385 R02, dated 
July 29, 2019 (GEnx-2B SB 72-0385); and GEnx-2B SB 72-0398 R00, dated 
October 30, 2019 (GEnx-2B SB 72-0398).
    GEnx-1B SB 72-0448 describes procedures for performing a BSI or an 
ECI of the stage 8 aft web of the HPC stages 6-10 rotor spool for GEnx-
1B model turbofan engines. GEnx-1B SB 72-0460 describes procedures for 
performing a BSI or an ECI of the stage 6 and stage 7 aft web of the 
HPC stages 6-10 rotor spool for GEnx-1B model turbofan engines.
    GEnx-2B SB 72-0385 describes procedures for performing a BSI or an 
ECI of the stage 8 aft web of the HPC stages 6-10 spool for GEnx-2B 
model turbofan engines. GEnx-2B SB 72-0398 describes procedures for 
performing a BSI or an ECI of the stage 6 and stage 7 aft web of the 
HPC stages 6-10 rotor spool for GEnx-2B model turbofan engines.

Costs of Compliance

    The FAA estimates that this AD affects 268 engines installed on 
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
BSI of GEnx-1B stage 6, stage 7, and    6 work-hours x $85 per                $0            $510         $89,760
 stage 8 webs, web transitions and       hour = $510.
 bore faces of the stages 6-10
 compressor rotor spool.
BSI of GEnx-2B stage 6, stage 7, and    6 work-hours x $85 per                 0             510          46,920
 stage 8 webs, web transitions and       hour = $510.
 bore faces of the stages 6-10
 compressor rotor spool.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
inspection. The agency has no way of determining the number of aircraft 
that might need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace the stages 6-10 compressor rotor spool  64 work-hours x $85 per hour =        $1,018,600      $1,024,040
                                                 $5,440.
----------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: General requirements. 
Under that section, Congress charges the FAA with promoting safe flight 
of civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of that 
authority because it addresses an unsafe condition that is likely to 
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:

[[Page 33497]]

    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2021-11-07 General Electric Company: Amendment 39-21569; Docket No. 
FAA-2020-0850; Project Identifier AD-2020-00288-E.

(a) Effective Date

    This airworthiness directive (AD) is effective July 30, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to:
    (1) General Electric Company (GE) GEnx-1B64, GEnx-1B64/P1, GEnx-
1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/P2, GEnx-1B70, GEnx-
1B70/75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-1B70/P2, GEnx-1B70C/
P1, GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/75/P2, GEnx-1B76/P2, 
GEnx-1B76A/P2 model turbofan engines with stages 6-10 compressor 
rotor spools in the high-pressure compressor (HPC) assembly with the 
following part numbers (P/N) installed:
    (i) P/N 2357M30G01, P/N 2357M30G02, P/N 2439M35G01, P/N 
2439M35G02, or P/N 2445M40G02, all serial numbers (S/Ns);
    (ii) P/N 2610M90G01 with the S/Ns listed in paragraph 4., 
APPENDIX--A, Table 1 of the GE GEnx-1B Service Bulletin (SB) 72-0472 
R02, dated November 5, 2020 (GEnx-1B SB 72-0472); and
    (iii) P/N 2628M56G01 with the S/Ns listed in paragraph 4., 
APPENDIX--A, Table 2 or Table 3 of GEnx-1B SB 72-0472.
    (2) GEnx-2B67, GEnx-2B67/P, GEnx-2B67B model turbofan engines 
with the following stages 6-10 compressor rotor spools P/Ns 
installed:
    (i) P/N 2357M30G02, P/N 2439M35G02, or P/N 2445M40G02, all S/Ns;
    (ii) P/N 2340M36G01 with S/Ns listed in paragraph 4., APPENDIX--
A, Table 1 of GE GEnx-2B SB 72-0415 R02, dated November 5, 2020 
(GEnx-2B SB 72-0415); and
    (iii) P/N 2628M56G01 with S/Ns listed in paragraph 4., 
APPENDIX--A, Table 2 or Table 3 of GEnx-2B SB 72-0415.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by a finding during an inspection that two 
stages 6-10 compressor rotor spools were damaged at similar 
locations. In addition, the manufacturer reported that certain 
stages 6-10 compressor rotor spool webs did not undergo a required 
fluorescent penetrant inspection (FPI) during production. The FAA is 
issuing this AD to prevent failure of the compressor rotor spool. 
The unsafe condition, if not addressed, could result in uncontained 
release of debris, damage to the engine, and damage to the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) For all affected GEnx-1B and GEnx-2B model turbofan engines, 
before exceeding the compliance time in Table 1 to paragraph (g)(1) 
of this AD, perform a borescope inspection (BSI) or eddy current 
inspection (ECI) of the stage 6, stage 7, and stage 8 webs, web 
transitions, and bore faces of the stages 6-10 compressor rotor 
spool in accordance with the Accomplishment Instructions, paragraph 
3, of GEnx-1B SB 72-0472 (for GEnx-1B models) or the Accomplishment 
Instructions, paragraph 3, of GEnx-2B SB 72-0415 (for GEnx-2B 
models).

                       Table 1 to Paragraph (g)(1)
------------------------------------------------------------------------
Cycles Since New (CSN) accumulated
   on the stages 6-10 compressor               Compliance time
            rotor spool
------------------------------------------------------------------------
Less than 6,400 CSN...............  Next engine shop visit or before the
                                     stages 6-10 compressor rotor spool
                                     accumulates 6,500 CSN, whichever
                                     occurs first after the effective
                                     date of this AD.
6,400 CSN or greater..............  Within 100 flight cycles after the
                                     effective date of this AD.
------------------------------------------------------------------------

    (i) For GEnx-1B model turbofan engines, except those identified 
in paragraph 4, APPENDIX--A, Table 3 of SB 72-0472, if, before the 
effective date of this AD, the engines have undergone inspections of 
the aft web of stage 6, stage 7, and stage 8 of the stages 6-10 
compressor rotor spool using both GE GEnx-1B SB 72-0448 R00, dated 
July 29, 2019, and GE GEnx-1B SB 72-0460 R00, dated October 30, 
2019, regardless of the CSN accumulated on the stages 6-10 
compressor rotor spool, perform the inspection required by paragraph 
(g)(1) of this AD no later than the next engine shop visit after the 
effective date of this AD.
    (ii) For GEnx-2B model turbofan engines, except those identified 
in paragraph 4., APPENDIX--A, Table 3 of SB 72-0415, if, before the 
effective date of this AD, the engines have undergone inspections of 
the aft web of stage 6, stage 7, and stage 8 of the stages 6-10 
compressor rotor spool using both GE GEnx-2B SB 72-385 R02, dated 
July 29, 2019, and GE GEnx-2B SB 72-0398 R00, dated October 30, 
2019, regardless of the CSN accumulated on the stages 6-10 
compressor rotor spool, perform the inspection required by paragraph 
(g)(1) of this AD no later than the next engine shop visit after the 
effective date of this AD.
    (2) For all affected GEnx-1B and GEnx-2B model turbofan engines, 
during the inspections required by paragraph (g)(1) of this AD, if a 
rejectable indication is found, before further flight, remove the 
stages 6-10 compressor rotor spool from service and replace it with 
a part eligible for installation.

(h) Definitions

    (1) 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 flanges, except that the 
separation of engine flanges solely for the purposes of 
transportation of the engine without subsequent engine maintenance 
does not constitute an engine shop visit.
    (2) For the purpose of this AD, a rejectable indication is:
    (i) A BSI indication that does not meet the BSI serviceable or 
repairable limits referenced in the Accomplishment Instructions, 
paragraph 3.A.(1)(a)2, of GEnx-1B SB 72-0472, or paragraph 
3.A.(1)(a)2 of GEnx-2B SB 72-0415, and the affected part has not 
undergone a subsequent ECI; or
    (ii) A BSI indication that does not meet the BSI serviceable or 
repairable limits referenced in the Accomplishment Instructions, 
paragraph 3.A.(1)(a)2, of GEnx-1B SB 72-0472, or paragraph 
3.A.(1)(a)2 of GEnx-2B SB 72-0415, and the affected part has 
undergone a subsequent ECI in which the indication did not meet the 
ECI serviceable or repairable limits referenced in the

[[Page 33498]]

Accomplishment Instructions, paragraph 3.A.(1)(b) of GEnx-1B SB 72-
0472, or paragraph 3.A.(1)(b) of GEnx-2B SB 72-0415; or
    (iii) An ECI indication that does not meet the serviceable or 
repairable limits referenced in the Accomplishment Instructions, 
paragraph 3.A.(1)(b) of GEnx-1B SB 72-0472, or paragraph 3.A.(1)(b) 
of GEnx-2B SB 72-0415.

(i) Credit for Previous Actions

    (1) For affected GEnx-1B model turbofan engines, you may take 
credit for the BSI or ECI required by paragraph (g)(1) of this AD, 
if you performed an ECI of the stages 6-10 compressor rotor spool 
webs, web transitions, and bore faces before the effective date of 
this AD using Subtask 72-31-45-160-002 of TASK 72-31-45-200-807 in 
GE GEnx-1B Engine Manual 05-21-00, Life Limits 001 Mandatory 
Inspections, Rev. 31, dated January 31, 2020, or earlier, and no 
rejectable indications were found.
    (2) For affected GEnx-2B model turbofan engines, you may take 
credit for the BSI or ECI required by paragraph (g)(1) of this AD, 
if you performed and ECI of the stages 6-10 compressor rotor spool 
webs, web transitions, and bore faces before the effective date of 
this AD using Subtask 72-31-45-160-002 of TASK 72-31-45-200-801 in 
GE GEnx-2B Engine Manual 05-21-00, Life Limits 001 Mandatory 
Inspections, Rev. 24, dated January 31, 2020, or earlier, and no 
rejectable indications were found.
    (3) For affected GEnx-1B model turbofan engines, you may take 
credit for the BSI or ECI required by paragraph (g)(1) of this AD, 
if you performed that inspection before the effective date of this 
AD using GE GEnx-1B Service Bulletin (SB) 72-0472 R00, dated April 
24, 2020, or GE GEnx-1B SB 72-0472 R01, dated July 24, 2020, and no 
rejectable indications were found.
    (4) For affected GEnx-2B model turbofan engines, you may take 
credit for the BSI or ECI required by paragraph (g)(1) of this AD, 
if you performed that inspection before the effective date of this 
AD using GE GEnx-2B SB 72-0415 R00, dated April 24, 2020, or GE 
GEnx-2B SB 72-0415 R01, dated July 24, 2020, and no rejectable 
indications were found.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO Branch, FAA, has the authority to approve 
AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
certification office, send it to the attention of the person 
identified in Related Information. You may email your request to: 
ANE-AD-AMOC@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    For more information about this AD, contact Mehdi Lamnyi, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7743; fax: (781) 238-7199; 
email: Mehdi.Lamnyi@faa.gov.

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) GE GEnx-1B Service Bulletin (SB) 72-0472 R02, dated November 
5, 2020.
    (ii) GE GEnx-2B SB 72-0415 R02, dated November 5, 2020.
    (3) For General Electric Company service information identified 
in this AD, contact General Electric Company, 1 Neumann Way, 
Cincinnati, OH 45215; phone: (513) 552-3272; email: 
aviation.fleetsupport@ae.ge.com; website: www.ge.com.
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 1200 District Avenue, 
Burlington, MA 01803. For information on the availability of this 
material at the FAA, call (781) 238-7759.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: fedreg.legal@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on May 19, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-13424 Filed 6-24-21; 8:45 am]
BILLING CODE 4910-13-P