Document ID: FAA-2022-1405-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: CFM International, S.A. Turbofan Engines
Posted Date: 2022-12-01T05:00Z

[Federal Register Volume 87, Number 230 (Thursday, December 1, 2022)]
[Proposed Rules]
[Pages 73683-73686]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-26126]

 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 87, No. 230 / Thursday, December 1, 2022 / 
Proposed Rules  

[[Page 73683]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1405; Project Identifier AD-2022-01070-E]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) 
2021-10-09, which applies to 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. AD 2021-10-09 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. 
Since the FAA issued AD 2021-10-09, the manufacturer notified the FAA 
that the service information incorrectly lists the year of certain 
honeycomb repairs. Additionally, the manufacturer notified the FAA that 
affected HPT inner stationary seals could potentially be installed on 
CFM CFM56-5C model turbofan engines. This proposed AD would 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. 
This proposed AD would also revise the applicability to add CFM CFM56-
5C model turbofan engines. The FAA is proposing this AD to address the 
unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by January 17, 
2023.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to regulations.gov. Follow 
the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    AD Docket: You may examine the AD docket at regulations.gov by 
searching for and locating Docket No. FAA-2022-1405; 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 NPRM, any comments 
received, and other information. The street address for Docket 
Operations is listed above.
    Material Incorporated by Reference:
     For CFM service information identified in this NPRM, 
contact CFM International Inc., Aviation Operations Center, 1 Neumann 
Way, M/D Room 285, Cincinnati, OH 45125; phone: (877) 432-3272; 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 (817) 222-5110.

FOR FURTHER INFORMATION CONTACT: Kevin Clark, Aviation Safety Engineer, 
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 
(781) 238-7088; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2022-1405; Project Identifier 
AD-2022-01070-E'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
the proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
regulations.gov, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to Kevin 
Clark, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803. Any commentary that the FAA receives which is not 
specifically designated as CBI will be placed in the public docket for 
this rulemaking.

Background

    The FAA issued AD 2021-10-09, Amendment 39-21542 (86 FR 27264, May 
20, 2021) (AD 2021-10-09), for all CFM CFM56-5B and CFM56-7B model 
turbofan engines with an HPT inner stationary seal, part number (P/N) 
1808M56G01, installed. AD 2021-10-09 was prompted by cracks found in 
the rotating air HPT front seal. After investigation, CFM determined 
that the HPT inner stationary seal, P/N 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 may have a condition that could lead to a localized separation

[[Page 73684]]

of the replaced honeycomb, which may reduce the life of the rotating 
air HPT front seal. AD 2021-10-09 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 agency issued AD 2021-10-09 to 
prevent failure of the HPT inner stationary seal and the rotating air 
HPT front seal, which could result in uncontained release of the 
rotating air HPT front seal, damage to the engine, and damage to the 
airplane.

Actions Since AD 2021-10-09 Was Issued

    Since the FAA issued AD 2021-10-09, the manufacturer notified the 
FAA that the service information, which is incorporated by reference, 
incorrectly lists the year of certain honeycomb repairs. The 
manufacturer subsequently published revised service information that 
establishes a single date for the honeycomb repairs. Additionally, the 
manufacturer notified the FAA that affected HPT inner stationary seals 
could be installed on CFM CFM56-5C model turbofan engines. The FAA, 
therefore, determined that the unsafe condition is likely to exist or 
develop on CFM CFM56-5C model turbofan engines with an affected HPT 
inner stationary seal installed.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed the following service information:
     CFM Service Bulletin (SB) CFM56-5C S/B 72-0796, Revision 
02, dated August 10, 2022.
     CFM SB CFM56-5B S/B 72-0952, Revision 02, dated August 10, 
2022.
     CFM SB CFM56-7B S/B 72-1054, Revision 02, dated August 10, 
2022.
    This service information, differentiated by engine model, specifies 
procedures for inspecting the 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.

Proposed AD Requirements in This NPRM

    This proposed AD would retain none of the requirements of AD 2021-
10-09. This proposed AD would 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. This proposed AD would also revise the 
applicability to add CFM CFM56-5C model turbofan engines.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 210 engines installed on airplanes of U.S. registry. Operators 
have the option to replace or repair the affected HPT inner stationary 
seal. The parts cost includes the estimated costs for replacement with 
a repaired HPT inner stationary seal.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 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 
proposed 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

    The FAA determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would not have a significant economic impact, positive or 
negative, on a substantial number of small entities

[[Page 73685]]

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 Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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:
0
a. Removing Airworthiness Directive 2021-10-09, Amendment 39-21542 (86 
FR 27264, May 20, 2021); and
0
b. Adding the following new airworthiness directive:

CFM International, S.A.: Docket No. FAA-2022-1405; Project 
Identifier AD-2022-01070-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by January 17, 2023.

(b) Affected ADs

    This AD replaces AD 2021-10-09, Amendment 39-21542 (86 FR 27264, 
May 20, 2021) (AD 2021-10-09).

(c) Applicability

    This AD applies to CFM International, S.A. (CFM) model turbofan 
engines identified in Table 1 to paragraph (c) of this AD with an 
installed high-pressure turbine (HPT) inner stationary seal, part 
number (P/N) 1808M56G01, that has a serial number (S/N) listed in 
Table 1 of CFM Service Bulletin (SB) CFM56-5B S/B 72-0952, Revision 
02, dated August 10, 2022 (CFM SB CFM56-5B S/B 72-0952); Table 1 of 
CFM SB CFM56-5C S/B 72-0796, Revision 02, dated August 10, 2022 (CFM 
SB CFM56-5C S/B 72-0796); or Table 1 of CFM SB CFM56-7B S/B 72-1054, 
Revision 02, dated August 10, 2022 (CFM SB CFM56-7B S/B 72-1054).

          Table 1 to Paragraph (c)--CFM Model Turbofan Engines
------------------------------------------------------------------------
          Make                                Model
------------------------------------------------------------------------
CFM....................  CFM56-5B1, CFM56-5B1/2P, CFM56-5B1/3, CFM56-5B1/
                          P, CFM56-5B2, CFM56-5B2/2P, CFM56-5B2/3, CFM56-
                          5B2/P, CFM56[dash]5B3/2P, CFM56[dash]5B3/2P1,
                          CFM56-5B3/3, CFM56-5B3/3B1, CFM56-5B3/P,
                          CFM56[dash]5B3/P1, CFM56[dash]5B4, CFM56-5B4/
                          2P, CFM56[dash]5B4/2P1, CFM56[dash]5B4/3,
                          CFM56[dash]5B4/3B1, CFM56-5B4/P, CFM56-5B4/P1,
                          CFM56[dash]5B5, CFM56-5B5/3, CFM56-5B5/P,
                          CFM56[dash]5B6, CFM56-5B6/2P, CFM56-5B6/3,
                          CFM56-5B6/P, CFM56-5B7, CFM56-5B7/3,
                          CFM56[dash]5B7/P, CFM56-5B8/3, CFM56-5B8/P,
                          CFM56-5B9/2P, CFM56[dash]5B9/3, CFM56[dash]5B9/
                          P.
CFM....................  CFM56-5C2, CFM56-5C2/4, CFM56-5C2/F, CFM56-5C2/
                          F4, CFM56[dash]5C2/G, CFM56-5C2/G4, CFM56-5C2/
                          P, CFM56-5C3/F, CFM56[dash]5C3/F4, CFM56-5C3/
                          G, CFM56-5C3/G4, CFM56-5C3/P, CFM56[dash]5C4,
                          CFM56-5C4/1, CFM56-5C4/1P, CFM56-5C4/P.
CFM....................  CFM56-7B20, CFM56-7B20/2, CFM56-7B20/3,
                          CFM56[dash]7B20E, CFM56[dash]7B22, CFM56-7B22/
                          2, CFM56-7B22/3, CFM56-7B22/3B1,
                          CFM56[dash]7B22/B1, CFM56-7B22E, CFM56-7B22E/
                          B1, CFM56[dash]7B24, CFM56[dash]7B24/2, CFM56-
                          7B24/3, CFM56-7B24/3B1, CFM56-7B24/B1, CFM56-
                          7B24E, CFM56-7B24E/B1, CFM56[dash]7B26, CFM56-
                          7B26/2, CFM56[dash]7B26/3, CFM56-7B26/3B1,
                          CFM56-7B26/3B2, CFM56[dash]7B26/3B2F,
                          CFM56[dash]7B26/3F, CFM56[dash]7B26/B1, CFM56-
                          7B26/B2, CFM56-7B26E, CFM56[dash]7B26E/B1,
                          CFM56-7B26E/B2, CFM56[dash]7B26E/B2F,
                          CFM56[dash]7B26E/F, CFM56-7B27, CFM56-7B27/2,
                          CFM56-7B27/3, CFM56[dash]7B27/3B1, CFM56-7B27/
                          3B1F, CFM56[dash]7B27/3B3, CFM56[dash]7B27/3F,
                          CFM56-7B27/B1, CFM56-B27/B3, CFM56-7B27A,
                          CFM56-7B27A/3, CFM56-7B27AE, CFM56-7B27E,
                          CFM56-7B27E/B1, CFM56-7B27E/B1F, CFM56-7B27E/
                          B3, CFM56[dash]7B27E/F.
------------------------------------------------------------------------

(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.

(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 an HPT inner stationary seal that is eligible for installation.
    (2) After removing the affected HPT inner stationary seal 
required by paragraph (g)(1) of this AD, inspect the removed HPT 
inner stationary seal for honeycomb separation in accordance with 
the Accomplishment Instructions, paragraph 3.C.(1), of CFM SB CFM56-
5B S/B 72-0952; CFM SB CFM56-5C S/B 72-0796; or CFM SB CFM56-7B S/B 
72-1054, as applicable by engine model.
    (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 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 Table 1 of CFM SB CFM56-5B S/B 72-
0952; Table 1 of CFM SB CFM56-5C S/B 72-0796; or Table 1 CFM SB 
CFM56-7B S/B 72-1054; or
    (ii) With a P/N 1808M56G01 and an S/N listed in Table 1 of CFM 
SB CFM56-5B S/B 72-0952; Table 1 of CFM SB CFM56-5C S/B 72-0796; or 
Table 1 of CFM SB CFM56-7B S/B 72-1054, that has been repaired as 
specified in CFM56-5B ESM, 72-41-03, REPAIR 003; CFM56-5C ESM, 72-
41-03, REPAIR 003; or CFM56-7B ESM, 72-41-03, REPAIR 003, as 
applicable by engine model, after December 31, 2012.
    (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 
new or HPT rotor blades that have been inspected and returned to a 
serviceable condition using FAA-approved maintenance procedures.

[[Page 73686]]

    (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) Credit for Previous Actions

    You may take credit for the actions specified in paragraphs 
(g)(1) through (3) of this AD, if you performed those actions before 
the effective date of this AD using CFM SB CFM56-5B S/B 72-0952, 
Revision 01, dated January 15, 2020, CFM SB CFM56-7B S/B 72-1054, 
Revision 01, dated January 15, 2020, or CFM SB CFM56-5C S/B 72-0796 
Revision 01, dated January 15, 2020.

(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 paragraph (k)(1) of this AD and email 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.
    (3) AMOCs approved for AD 2021-10-09 (86 FR 27264, May 20, 2021) 
are approved as AMOCs for the corresponding provisions of this AD.

(k) Related Information

    (1) For more information about this AD, contact Kevin Clark, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7088; email: 
[email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (1)(3) and (4) of this AD.

(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 (SB) CFM56-5C S/B 72-0796, Revision 02, 
dated August 10, 2022.
    (ii) CFM SB CFM56-5B S/B 72-0952, Revision 02, dated August 10, 
2022.
    (iii) CFM SB CFM56-7B S/B 72-1054, Revision 02, dated August 10, 
2022.
    (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; 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 (817) 222-5110.
    (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: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on October 27, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-26126 Filed 11-30-22; 8:45 am]
BILLING CODE 4910-13-P