Airworthiness Directives; CFM International, S.A. Turbofan Engines, 27264-27268 [2021-10607]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 86, Number 96 (Thursday, May 20, 2021)]
[Rules and Regulations]
[Pages 27264-27268]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-10607]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0568; Project Identifier 2019-NE-20-AD; Amendment 
39-21542; AD 2021-10-09]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A. Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
CFM International, S.A. (CFM) CFM56-5B and CFM56-7B model turbofan 
engines with a certain high-pressure turbine (HPT) inner stationary 
seal installed. This AD was prompted by cracks found in the rotating 
air HPT front seal. This AD requires removal, inspection, and 
replacement of the affected HPT inner stationary seal and, depending on 
the findings, replacement of the rotating air HPT front seal, HPT rotor 
blades, and No. 3 ball bearing. The FAA is issuing this AD to address 
the unsafe condition on these products.

DATES: This AD is effective June 24, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of June 24, 
2021.

ADDRESSES: For service information identified in this final rule, 
contact CFM International Inc., Aviation Operations Center, 1 Neumann 
Way, M/D Room 285, Cincinnati, OH 45125; phone: (877) 432-3272; fax: 
(877) 432-3329; email: [email protected]. 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-2019-0568.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2019-0568; 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: Christopher McGuire, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7120; fax: (781) 238-7199; email: 
[email protected].

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 all CFM CFM56-5B and 
CFM56-7B model turbofan engines with a certain HPT inner stationary 
seal installed. The NPRM published in the Federal Register on September 
20, 2019 (84 FR 49487). The NPRM was prompted by a report that two 
cracks were discovered on a CFM CFM56-5B model turbofan engine rotating 
air HPT front seal during a routine engine shop visit. After 
investigation, CFM determined that the HPT inner stationary seal, part 
number 1808M56G01, may not have received the correct braze heat treat 
cycle at the time of the honeycomb replacement. As a result, the 
affected HPT inner stationary seal could lead to a localized separation 
of the replaced honeycomb, which may reduce the life of the rotating 
air HPT front seal. In the NPRM, the FAA proposed to require removal, 
inspection, and replacement of the affected HPT inner stationary seal 
and, depending on the findings, replacement of the rotating air HPT 
front seal, HPT rotor blades, and No. 3 ball bearing. The FAA is 
issuing this AD

[[Page 27265]]

to address the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from nine commenters. The commenters were 
Air Line Pilots Association, International (ALPA); American Airlines 
(AAL); Azur Aviation (Azur); The Boeing Company (Boeing); CFM; Delta 
Air Lines, Inc. (Delta); United Airlines (UAL); MTU Maintenance Canada 
(MTU) and Magnetic MRO. Four of the nine commenters requested changes 
that resulted in updates to this AD. Three commenters requested 
clarification on definitions. Two commenters requested updates to the 
service information. Two commenters expressed support for the AD. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.
Request To Clarify Parts That Can Be Returned to Service
    Azur requested that the FAA clarify the parts that can be returned 
to service after removal. Azur reasoned that paragraph (g)(1) of this 
AD requires that an HPT inner stationary seal be removed from service 
and replaced with either a part that is not listed in the service 
information or a repaired part identified in paragraph (h)(2), 
Definitions, of this AD. In contrast, paragraphs (g)(3)(i) and (iii) of 
this AD, respectively, indicate only to remove the rotating air HPT 
front seal and No. 3 ball bearing from service and replace them with a 
``part eligible for installation.''
    Azur suggested adding one of the following to this AD to remove the 
ambiguity: (1) Remove ``remove from service'' from paragraph (g)(1) of 
this AD; (2) Identify rotating air HPT front seals and No. 3 ball 
bearings that are not eligible for installation; (3) Add an 
``Installation Prohibition'' paragraph for the removed rotating air HPT 
front seal and No. 3 ball bearing; (4) Indicate what to do with the 
removed rotating air HPT front seal and No. 3 ball bearing in 
paragraphs (g)(3)(i) and (iii) of this AD, such as discard these parts; 
or (5) Identify instruction for the removed rotating air HPT front 
seals and No. 3 ball bearings.
    Use of ``remove from service'' in this AD indicates that the 
rotating air HPT front seal and No. 3 ball bearing should no longer be 
installed on an engine. Therefore, neither the removed rotating air HPT 
front seal nor the removed No. 3 ball bearing can be repaired and 
returned to service. The FAA, however, updated paragraph (h), 
Definitions, of this AD, to clarify that a part eligible for 
installation for both a rotating air HPT front seal and a No. 3 ball 
bearing refers to parts that were not removed from service based on the 
findings of honeycomb separation of the HPT inner stationary seal. The 
FAA also updated paragraph (g)(1) of this AD to remove ``remove from 
service'' to clarify that the HPT inner stationary seal can be repaired 
and returned to service. The FAA also moved the definition of an HPT 
inner stationary seal that is eligible for installation from paragraph 
(g)(1) to paragraph (h)(1) of this AD.
Request To Update the Definition of Engine Shop Visit
    AAL, Delta, and UAL requested updates or clarification of the 
definition of an ``engine shop visit'' provided in paragraph (h)(1) of 
this AD.
    AAL requested that the FAA update the definition of an engine shop 
visit to clarify circumstances that are not an engine shop visit. AAL 
reasoned that CFM Service Bulletin (SB) CFM56-7B S/B 72-0972 provides 
guidance on when AD mandated actions can be accomplished to avoid undue 
burden on operators, specifically in circumstances when engines are 
inducted to the shop for quick corrective action, such as repair for 
foreign object damage.
    UAL requested that the FAA update the definition of an engine shop 
visit to specify which major mating engine case flanges need to be 
separated to be an engine shop visit as defined. UAL stated that the 
ambiguity of the ``major mating engine case flange'' may result in an 
inspection of the HPT inner stationary seal for honeycomb separation 
when the core is not exposed, such as during fan case replacement.
    Delta recommended that the manufacturer define ``engine shop 
visit'' in its service information.
    The FAA agrees that the definition of an engine shop visit in this 
AD does not include the separation of engine flanges solely for the 
purpose of transportation of the engine or replacing the fan or 
propulsor without subsequent maintenance. All other separations of 
major mating engine case flanges are an engine shop visit, as defined, 
and require removal, replacement, and inspection of the HPT inner 
stationary seal as required by paragraphs (g)(1) and (2) of this AD. 
The FAA changed the definition of ``engine shop visit'' in paragraph 
(h) this AD to clarify the definition of an engine shop visit.
    The FAA did not revise this AD in response to Delta's comment. The 
FAA notes, however, that in CFM Service Bulletin (SB) CFM56-5B S/B 72-
0952, Revision 01, and CFM SB CFM56-7B S/B 72-1054, Revision 01, both 
dated January 15, 2020, the manufacturer updated the SBs to clarify 
that the quick turn shop visit type is not included in the SB's 
definition of ``shop visit.''
Request To Change Inspection of HPT Rotor Blade To Remove Debris
    AAL requested that the FAA change paragraph (g)(3)(ii) of this AD 
to ``Remove the HPT rotor blade from service and inspect per CFM56-7B 
CFMI-TP.SM.10 Engine Shop Manual (ESM) 72-52-01-09 High Pressure 
Turbine Rotor Blades--Inspection 001 or replace with parts eligible for 
installation.'' AAL reasoned that the HPT rotor blade collects various 
types of debris over its service life, so attempting to determine if 
the debris is honeycomb material based upon a general visual inspection 
is subjective and open to interpretation. Therefore, AAL suggested that 
removing the HPT rotor blades would ensure that the repair facility 
could remove the debris in the internal cavities and return the HPT 
rotor blades to service.
    Since the NPRM was published, the manufacturer revised the service 
information, removing the inspection of the HPT rotor blade internal 
cavities for honeycomb metal debris. As a result, the FAA changed 
paragraph (g)(3)(ii) of this AD to eliminate the requirement to inspect 
the HPT rotor blade internal cavities for honeycomb metal debris. The 
FAA also removed the estimated cost associated with the inspection of 
the HPT rotor blade internal cavities for honeycomb metal debris from 
this AD.
Request To Clarify Reason To Replace No. 3 Ball Bearing
    Magnetic MRO requested clarification for the reason to replace the 
No. 3 ball bearing if metal debris is found in the HPT blade cavities.
    In the NPRM, the FAA proposed to require replacement of the No. 3 
ball bearing if honeycomb separation was found during the inspection 
required by paragraph (g)(2) of this AD. The replacement of the No. 3 
ball bearing is not linked to a finding of debris in the HPT rotor 
blade internal cavities but is required if honeycomb separation is 
found. Honeycomb separation results in increased secondary air flow 
impinging on the rotating air HPT front seal, which increases the axial 
load on the No. 3 ball bearing. This increased axial load impacts the 
durability of the No. 3 ball bearing. The FAA did not change this AD 
based on this comment.

[[Page 27266]]

Request To Add a Terminating Action
    AAL requested that the FAA update paragraph (g)(1) of this AD to 
include, ``Accomplishment of these instructions are considered 
terminating action to this AD.'' AAL reasoned that this statement 
provides specific closure since the corrective action has been clearly 
defined and approved by the FAA. AAL suggested this maintenance action 
is not recurring and, as such, would constitute an appropriate 
terminating action.
    The FAA disagrees with adding the terminating action statement. 
Performing the actions required by this AD achieves compliance with 
this AD. A statement of terminating action is unnecessary.
Request To Clarify Compliance
    MTU commented that this AD describes actions to be performed if 
damage is found, but does not describe actions to be performed when 
damage is not found as specified in CFM SB CFM56-7B S/B 72-1054, 
Revision 01, dated January 15, 2020. MTU asked if the AD could 
reference action that needs to be performed when the engine is inducted 
and disassembled for reasons other than HPT inner stationary seal issue 
and damage (or no damage) is found.
    The FAA disagrees with requiring actions that are not related to 
the unsafe condition described in this AD. The HPT inner stationary 
seal is not typically exposed unless the engine is undergoing an engine 
shop visit. However, if damage to the HPT inner stationary seal is 
found during inspections not related to this AD, the ESM provides 
criteria to determine appropriate action.
Request To Incorporate AC 20-176A in Service Information
    AAL and Delta requested that CFM incorporate AC 20-176A into both 
CFM SB CFM56-5B S/B 72-0952, Revision 01, dated January 15, 2020, and 
CFM SB CFM56-7B S/B 72-1054, Revision 01, dated January 15, 2020, for 
the purpose of ``. . . distinguishing which steps in an SB will have a 
direct effect on detecting, preventing, resolving, or eliminating the 
unsafe condition identified in an AD.'' The commenters reasoned that 
CFM should identify the steps required for compliance (RC) in the 
service information. AAL added that the RC designation reduces global 
AMOCs and streamlines the accomplishment of key tasks while meeting 
strict regulatory compliance.
    The FAA agrees that adding the RC designation to the required 
service information steps provides clarity to the operators. CFM added 
the RC designation to CFM SB CFM56-5B S/B 72-0952, Revision 01, dated 
January 15, 2020, and CFM SB CFM56-7B S/B 72-1054, Revision 01, dated 
January 15, 2020. The FAA did not change this AD.
Request To Update References to the ESM
    Delta requested that the FAA update paragraphs (c)(2) and (h)(2) of 
this AD to reference the CFM56-5B ESM and the CFM56-7B ESM entirely, 
rather than specific repair tasks within the ESMs. Delta reasoned that 
the CFM56-5B ESM and CFM56-7B ESM might change in future revisions.
    The FAA disagrees with changing the references from the specific 
repair tasks. Paragraph (c)(2), Applicability, and paragraph (h)(2), 
Definitions, of this AD refer to specific repair tasks within CFM56-5B 
ESM and CFM56-7B ESM that are required to return a HPT inner stationary 
seal to service. The FAA did not change this AD, but will consider 
requests for AMOCs if the repair tasks change in future revisions of 
the ESM.
Comment on Revising Service Information
    CFM stated that they would update CFM SB CFM56-5B S/B 72-0952 and 
CFM SB CFM56-7B S/B 72-1054 based on feedback from operators. CFM 
indicated it would update the definition of ``shop visit'' to clarify 
that replacing a fan disk is not considered a shop visit. CFM further 
indicated that it would clarify that if honeycomb separation is found, 
then the HPT blades may be scrapped or overhauled. Finally, CFM noted 
that it would revise the SBs by adding ``RC'' to those tasks required 
for compliance.
    The FAA notes that it has revised this AD by referring to CFM SB 
CFM56-5B S/B 72-0952, Revision 01, dated January 15, 2020, and CFM SB 
CFM56-7B S/B 72-1054, Revision 01, dated January 15, 2020. In addition, 
the FAA has reviewed the changes included in Revision 01 of these SBs 
and determined that these are clarifying changes only and impose no 
additional burden to operators.
Request To Allow Use of Later Revisions of Service Information
    AAL and Delta requested that the FAA add the phrase ``or later'' 
when referencing the service information in this AD. AAL stated that 
specifying ``or later'' could prevent numerous requests for alternative 
methods of compliance (AMOCs) if the manufacturer revises the service 
information. AAL also stated that this request aligns with paragraph 2-
3.d of Advisory Circular No. 20-176A, ``Service Bulletins Related to 
Airworthiness Directives and Indicating FAA Approval on Service 
Documents,'' dated June 16, 2014 (AC 20-176A).
    The FAA disagrees with adding language that allows the use of later 
revisions of service information when performing the required actions 
of this AD. Later revisions of the service information have not been 
reviewed by the FAA. As noted, however, in a previous comment response, 
the FAA has revised this AD by referring to the latest published 
revisions of the referenced service information.
Support for No Reporting Requirement
    AAL expressed support for the No Reporting Requirement in paragraph 
(i) of this AD.
Support for the AD
    ALPA and Boeing expressed support for the AD as written.

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

Related Service Information Under 1 CFR Part 51

    The FAA reviewed CFM SB CFM56-5B S/B 72-0952, Revision 01, dated 
January 15, 2020, and CFM SB CFM56-7B S/B 72-1054, Revision 01, dated 
January 15, 2020. CFM SB CFM56-5B S/B 72-0952, Revision 01, describes 
procedures for repairing the CFM56-5B turbofan engine HPT inner 
stationary seal honeycomb. CFM SB CFM56-7B S/B 72-1054, Revision 01, 
describes procedures for repairing the CFM56-7B turbofan engine HPT 
inner stationary seal honeycomb. 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.

Costs of Compliance

    The FAA estimates that this AD affects 210 engines installed on 
airplanes of U.S. registry. Operators have the option to replace or 
repair the affected HPT inner stationary seal. The part cost is for 
replacement with a repaired HPT inner stationary seal.
    The FAA estimates the following costs to comply with this AD:

[[Page 27267]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Replace HPT inner stationary seal.....  1 work-hour x $85 per             $7,910          $7,995      $1,678,950
                                         hour = $85.
Inspect HPT inner stationary seal.....  1 work-hour x $85 per                  0              85          17,850
                                         hour = $85.
----------------------------------------------------------------------------------------------------------------

    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 engines 
that might need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace rotating air HPT front seal...........  1 work-hour x $85 per hour = $85        $344,600        $344,685
Replace HPT rotor blades (pair)...............  1 work-hour x $85 per hour = $85          31,000          31,085
Replace No. 3 ball bearing....................  1 work-hour x $85 per hour = $85          30,000          30,085
----------------------------------------------------------------------------------------------------------------

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:
    (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:

2021-10-09 CFM International, S.A.: Amendment 39-21542; Docket No. 
FAA-2019-0568; Project Identifier 2019-NE-20-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective June 24, 2021.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to all CFM International, S.A. (CFM) CFM56-
5B1, -5B1/2P, -5B1/3, -5B1/P, -5B2, -5B2/2P, -5B2/3, -5B2/P, -5B3/
2P, -5B3/2P1, -5B3/3, -5B3/3B1, -5B3/P, -5B3/P1, -5B4, -5B4/2P, -
5B4/2P1, -5B4/3, -5B4/3B1, -5B4/P, -5B4/P1, -5B5, -5B5/3, -5B5/P, -
5B6, -5B6/2P, -5B6/3, -5B6/P, -5B7, -5B7/3, -5B7/P, -5B8/3, -5B8/P, 
-5B9/2P, -5B9/3, -5B9/P, CFM56-7B20, -7B20/2, -7B20/3, -7B20E, -
7B22, -7B22/2, -7B22/3, -7B22/3B1, -7B22/B1, -7B22E, -7B22E/B1, -
7B24, -7B24/2, -7B24/3, -7B24/3B1, -7B24/B1, -7B24E, -7B24E/B1, -
7B26, -7B26/2, -7B26/3, -7B26/3B1, -7B26/3B2, -7B26/3B2F, -7B26/3F, 
-7B26/B1, -7B26/B2, -7B26E, -7B26E/B1, -7B26E/B2, -7B26E/B2F, -
7B26E/F, -7B27, -7B27/2, -7B27/3, -7B27/3B1, -7B27/3B1F, -7B27/3B3, 
-7B27/3F, -7B27/B1, -7B27/B3, -7B27A, -7B27A/3, -7B27AE, -7B27E, -
7B27E/B1, -7B27E/B1F, -7B27E/B3, and -7B27E/F model turbofan engines 
with a high-pressure turbine (HPT) inner stationary seal, part 
number (P/N) 1808M56G01 installed that has a serial number (S/N) 
listed in Planning Information, Paragraph 1.A., Table 1, of CFM 
Service Bulletin (SB) CFM56-5B S/B 72-0952, Revision 01, dated 
January 15, 2020, or in Planning Information, Paragraph 1.A., Table 
1, CFM SB CFM56-7B S/B 72-1054, Revision 01, dated January 15, 2020, 
installed.
    (2) This AD does not apply to affected CFM CFM56-5B and CFM56-7B 
model turbofan engines with the affected HPT inner stationary seal 
installed if the seal has been repaired as specified in CFM56-5B 
Engine Shop Manual (ESM), 72-41-03, REPAIR 003, or CFM56-7B ESM, 72-
41-03, REPAIR 003, after the year listed in Paragraph 1.A., Table 1, 
of CFM SB CFM56-5B S/B 72-0952, Revision 01, dated January 15, 2020, 
or Paragraph 1.A., Table 1, CFM SB CFM56-7B S/B 72-1054, Revision 
01, dated January 15, 2020.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by cracks found in the rotating air HPT 
front seal. The FAA is issuing this AD to prevent failure of the HPT 
inner stationary seal and the rotating air HPT front seal. The 
unsafe condition, if not addressed, could result in uncontained 
release of the rotating air HPT front seal, damage to the engine, 
and damage to the airplane.

(f) Compliance

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

[[Page 27268]]

(g) Required Actions

    (1) At the next engine shop visit after the effective date of 
this AD, remove the affected HPT inner stationary seal and replace 
with a HPT inner stationary seal that is eligible for installation.
    (2) After removing the affected HPT inner stationary seal 
required by paragraph (g)(1), inspect the removed HPT inner 
stationary seal for honeycomb separation, as defined in the 
Accomplishment Instructions, paragraph 3.C.(1), in CFM SB CFM56-5B 
S/B 72-0952, Revision 01, dated January 15, 2020, or in CFM SB 
CFM56-7B S/B 72-1054, Revision 01, dated January 15, 2020.
    (3) If honeycomb separation is found during the inspection 
required by paragraph (g)(2) of this AD, before further flight:
    (i) Remove the rotating air HPT front seal from service and 
replace with a rotating air HPT front seal that is eligible for 
installation.
    (ii) Remove the HPT rotor blades and replace them with HPT rotor 
blades eligible for installation.
    (iii) Remove the No. 3 ball bearing from service and replace 
with a No. 3 ball bearing 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 case flanges, except for 
the following situations, which do not constitute an engine shop 
visit.
    (i) Separation of engine flanges solely for the purpose of 
transportation of the engine without subsequent maintenance.
    (ii) Separation of engine flanges solely for the purpose of 
replacing the fan or propulsor without subsequent maintenance.
    (2) For the purpose of this AD, an HPT inner stationary seal 
that is eligible for installation is an HPT inner stationary seal:
    (i) That is not listed in Planning Information, Paragraph 1.A., 
Table 1, of CFM SB CFM56-5B S/B 72-0952, Revision 01, dated January 
15, 2020, or in Planning Information, Paragraph 1.A., Table 1, CFM 
SB CFM56-7B S/B 72-1054, Revision 01, dated January 15, 2020; or
    (ii) with a P/N 1808M56G01 and with a S/N listed in Paragraph 
1.A., Table 1, of CFM SB CFM56-5B S/B 72-0952, Revision 01, dated 
January 15, 2020, or Paragraph 1.A., Table 1, CFM SB CFM56-7B S/B 
72-1054, Revision 01, dated January 15, 2020, that has been repaired 
per CFM56-5B ESM, 72-41-03, REPAIR 003, or CFM56-7B ESM, 72-41-03, 
REPAIR 003, after the year listed in Paragraph 1.A., Table 1, of CFM 
SB CFM56-5B S/B 72-0952, Revision 01, dated January 15, 2020, or 
Paragraph 1.A., Table 1, CFM SB CFM56-7B S/B 72-1054, Revision 01, 
dated January 15, 2020.
    (3) For the purpose of this AD, a rotating air HPT front seal 
that is eligible for installation is any rotating air HPT front seal 
that was not removed from service as a result of the inspection of 
the HPT inner stationary seal required by paragraph (g)(2) of this 
AD in which there was a finding of honeycomb separation.
    (4) For the purpose of this AD, HPT rotor blades eligible for 
installation are new HPT rotor blades with zero flight hours since 
news or HPT rotor blades that have been inspected and returned to a 
serviceable condition using approved engine manual requirements.
    (5) For the purpose of this AD, a No. 3 ball bearing eligible 
for installation is any No. 3 ball bearing that was not removed from 
service as a result of the inspection of the HPT inner stationary 
seal required by paragraph (g)(2) of this AD in which there was a 
finding of honeycomb separation.

(i) No Reporting Requirement

    The reporting requirements contained within the SBs referenced 
in paragraph (g) of this AD are not required by this AD.

(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: 
[email protected].
    (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 Christopher McGuire, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7120; fax: (781) 238-7199; 
email: [email protected].

(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) CFM Service Bulletin CFM56-5B S/B 72-0952, Revision 01, 
dated January 15, 2020.
    (ii) CFM Service Bulletin CFM56-7B S/B 72-1054, Revision 01, 
dated January 15, 2020.
    (3) For CFM service information identified in this AD, contact 
CFM International Inc., Aviation Operations Center, 1 Neumann Way, 
M/D Room 285, Cincinnati, OH 45125; phone: (877) 432-3272; fax: 
(877) 432-3329; email: [email protected].
    (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: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on April 29, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-10607 Filed 5-19-21; 8:45 am]
BILLING CODE 4910-13-P