[Federal Register Volume 86, Number 219 (Wednesday, November 17, 2021)]
[Proposed Rules]
[Pages 64085-64089]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-24834]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 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.
 
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 

  Federal Register / Vol. 86, No. 219 / Wednesday, November 17, 2021 / 
Proposed Rules  

[[Page 64085]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0877; Project Identifier AD-2020-01316-T]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain The Boeing Company Model 747-100B SUD, 747-200B, 747-200C, 
747-200F, 747-300, 747SP, 747-400, 747-400D, and 747-400F series 
airplanes. This proposed AD was prompted by a determination that a 
certain fastener type that penetrates the fuel tank walls has 
insufficient bond to the structure, and energy from a lightning strike 
or high-powered short circuit could cause arcing to occur at the ends 
of fasteners in the fuel tanks. This proposed AD would require, for 
certain airplanes, reconfiguring the clamps of certain wire bundles, 
applying sealant to certain fasteners that penetrate the fuel tank 
walls, installing cushion clamps and polytetrafluoroethylene (TFE) 
sleeves, inspecting to determine if sealant was applied to certain 
fasteners, and applying sealant if necessary. This proposed AD would 
also require, for all airplanes, revising the maintenance or inspection 
program, as applicable, to incorporate new, more restrictive 
airworthiness limitations. 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 3, 
2022.

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 https://www.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.
    For service information identified in this NPRM, contact Boeing 
Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; 
telephone 562-797-1717; internet https://www.myboeingfleet.com. You may 
view this service information at the FAA, Airworthiness Products 
Section, Operational Safety Branch, 2200 South 216th St., Des Moines, 
WA. For information on the availability of this material at the FAA, 
call 206-231-3195. Boeing Special Attention Service Bulletin 747-57-
2327, Revision 8, dated November 13, 2020, is also available on the 
internet at https://www.regulations.gov by searching for and locating 
Docket No. FAA-2021-0877.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0877; 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.

FOR FURTHER INFORMATION CONTACT: Rose Len, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3604; 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-2021-0877; Project Identifier 
AD-2020-01316-T'' 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 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this proposed AD.

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 Rose 
Len, Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3604; email: [email protected]. 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 has examined the underlying safety issues involved in fuel 
tank explosions on several large transport airplanes, including the 
adequacy of existing regulations, the service history of airplanes 
subject to those regulations, and existing maintenance practices for 
fuel tank systems. As a result of those findings,

[[Page 64086]]

the FAA issued a final rule titled ``Transport Airplane Fuel Tank 
System Design Review, Flammability Reduction, and Maintenance and 
Inspection Requirements'' (66 FR 23086, May 7, 2001). In addition to 
new airworthiness standards for transport airplanes and new maintenance 
requirements, that rule included Amendment 21-78, which established 
Special Federal Aviation Regulation No. 88 (``SFAR 88'') at 14 CFR part 
21. Subsequently, SFAR 88 was amended by Amendment 21-82 (67 FR 57490, 
September 10, 2002; corrected at 67 FR 70809, November 26, 2002) and 
Amendment 21-83 (67 FR 72830, December 9, 2002; corrected at 68 FR 
37735, June 25, 2003, to change ``21-82'' to ``21-83'').
    Among other actions, SFAR 88 requires certain type design (i.e., 
type certificate (TC) and supplemental type certificate (STC)) holders 
to substantiate that their fuel tank systems can prevent ignition 
sources in the fuel tanks. This requirement applies to type design 
holders for large turbine-powered transport airplanes and for 
subsequent modifications to those airplanes. It requires them to 
perform design reviews and to develop design changes and maintenance 
procedures if their designs do not meet the new fuel tank safety 
standards. As explained in the preamble to the final rule published on 
May 7, 2001, the FAA intended to adopt airworthiness directives to 
mandate any changes found necessary to address unsafe conditions 
identified as a result of these reviews.
    In evaluating these design reviews, the FAA has established four 
criteria intended to define the unsafe conditions associated with fuel 
tank systems that require corrective actions. The percentage of 
operating time during which fuel tanks are exposed to flammable 
conditions is one of these criteria. The other three criteria address 
the failure types under evaluation: Single failures, combination of 
failures, and unacceptable (failure) experience. For all three failure 
criteria, the evaluations included consideration of previous actions 
taken that may mitigate the need for further action.
    The FAA has determined that the actions identified in this proposed 
AD are necessary to reduce the potential of ignition sources inside 
fuel tanks, which, in combination with flammable fuel vapors, could 
result in fuel tank explosion or fire.
    The FAA has received a report indicating that a certain type of 
fastener used in the fuel tank walls of Model 747 airplanes is 
insufficiently bonded to the airplane structure. Further, these 
fasteners do not have sufficient electrical insulation applied inside 
the fuel tanks to prevent arcing in the event of a lightning strike or 
high-powered short circuit. This condition, if not corrected, could 
result in a fuel tank explosion or fire.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Special Attention Service Bulletin 747-57-
2327, Revision 8, dated November 13, 2020. This service information 
describes procedures for reconfiguring the clamps of certain wire 
bundles, applying sealant to certain fasteners that penetrate the fuel 
tank walls, and installing cushion clamps and TFE sleeves on the wire 
bundles of the front spars and rear spars of the wings.
    The FAA also reviewed Boeing Service Bulletin 747-57-2326, Revision 
1, dated January 31, 2008. This service information describes 
procedures for, among other actions, applying sealant to certain 
fasteners.
    The FAA also reviewed The Boeing Company 747-400 Maintenance 
Planning Data (MPD) Document, Section 9, Airworthiness Limitations 
(AWL) and Certification Maintenance Requirements (CMRs), D621U400-9, 
Revision February 2020, which includes revised AWL tasks 28-AWL-33, 28-
AWL-34, and 28-AWL-37; and The Boeing Company 747-100/200/300/SP/SR 
Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs), D6-13747-CMR, Revision September 2020, which 
includes revised AWL tasks 28-AWL-25, 28-AWL-27, and 28-AWL-28. The 
revised AWL tasks describe fuel airworthiness limitation items (ALIs) 
and critical design configuration control limitations (CDCCLs) that 
address fuel tank systems. These documents are distinct because they 
apply to different airplane models. The new AWLs include:
     An ALI (periodic inspections) of the cushion clamps and 
teflon sleeving installed on out-of-tank wire bundles installed on 
brackets that are mounted directly on the fuel tanks;
     A CDCCL for the cushion clamps and teflon sleeving 
installed on out-of-tank wire bundles installed on brackets that are 
mounted directly on the fuel tanks; and
     A CDCCL for lightning, fault current or hot short 
protection features.
    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 the ADDRESSES section.

Other Relevant Rulemaking

    AD 2007-20-01, Amendment 39-15211 (72 FR 54533, September 26, 2007) 
(AD 2007-20-01), requires actions in accordance with Boeing Service 
Bulletin 747-57-2326, dated January 4, 2007; and Boeing Service 
Bulletin 747-57-2327, Revision 1, dated July 10, 2006. AD 2007-20-01 
applies to certain The Boeing Company Model 747-100B SUD, 747-200B, 
747-200C, 747-200F, 747-300, 747SP, 747-400, 747-400D, and 747-400F 
series airplanes. The FAA has determined that AD 2007-20-01 did not 
fully address the unsafe condition for Model 747-100B SUD, 747-200B, 
747-200C, 747-200F, 747-300, 747SP, 747-400, 747-400D, and 747-400F 
series airplanes. The service information for AD 2007-20-01 has been 
revised and contains additional work as described previously.

FAA's Determination

    The FAA is proposing this AD because the agency evaluated all the 
relevant information and determined the unsafe condition described 
previously is likely to exist or develop in other products of the same 
type design.

Proposed AD Requirements

    This proposed AD would require, for certain airplanes, 
reconfiguring the clamps of certain wire bundles, applying sealant to 
certain fasteners that penetrate the fuel tank walls, installing 
cushion clamps and TFE sleeves, inspecting to determine if sealant was 
applied to certain fasteners, and applying sealant if necessary. This 
proposed AD would also require, for all airplanes, revising the 
maintenance or inspection program, as applicable, to incorporate new, 
more restrictive airworthiness limitations.

Differences Between This Proposed AD and the Service Information

    Boeing Special Attention Service Bulletin 747-57-2327, Revision 8, 
dated November 13, 2020, specifies a compliance time of 60 months to 
accomplish Work Packages 13 through 20 and a compliance time of 27 
months to accomplish Work Package 21. The FAA has determined that all 
work packages may be done within 60 months as it is not necessary to 
accomplish Work Package 21 prior to the other work packages. The FAA 
has determined that the 60-month compliance time is appropriate and 
will not adversely affect safety.
    In The Boeing Company 747-100/200/300/SP/SR Airworthiness 
Limitations (AWLs) and Certification Maintenance Requirements (CMRs), 
D6-

[[Page 64087]]

13747-CMR, Revision September 2020, the ``Applicability'' of 
airworthiness limitations 28-AWL-25 and 28-AWL-27 specifies ``ALL'' and 
``NOTE.'' The FAA has determined that the applicability should be 
``Airplanes L/N 645 and on'' as those limitations do not apply to 
airplanes having line numbers 1 through 644 inclusive. In addition, the 
``Applicability Note'' in the Description column does not apply. This 
difference is specified in paragraph (h)(2) of the proposed AD.

Costs of Compliance

    The FAA estimates that this proposed AD affects 104 airplanes of 
U.S. registry. The FAA estimates the following costs to comply with 
this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
            Action                  Labor cost         Parts cost      Cost per product  Cost on U.S.  operators
----------------------------------------------------------------------------------------------------------------
Reconfiguring clamps,           Up to 30 work-     Up to $2,004.....  Up to $4,554.....  Up to $473,616.
 inspections, applying           hours x $85 per
 sealant, and installing         hour = Up to
 clamps and TFE sleeves.         $2,550.
----------------------------------------------------------------------------------------------------------------

    The FAA has determined that revising the maintenance or inspection 
program takes an average of 90 work-hours per operator, although the 
agency recognizes that this number may vary from operator to operator. 
Since operators incorporate maintenance or inspection program changes 
for their affected fleet(s), the FAA has determined that a per-operator 
estimate is more accurate than a per-airplane estimate. Therefore, the 
agency estimates the average total cost per operator to be $7,650 (90 
work-hours x $85 per work-hour).
    The FAA estimates the following costs to do any necessary 
application of sealant that would be required based on the results of 
the proposed inspections. The agency has no way of determining the 
number of aircraft that might need this action:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                Action                        Labor cost               Parts cost            Cost per product
----------------------------------------------------------------------------------------------------------------
Applying sealant.....................  Up to 102 work-hours x   Up to $6,813...........  Up to $15,483.
                                        $85 per hour = Up to
                                        $8,670.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some or all of the costs of 
this proposed AD may be covered under warranty, thereby reducing the 
cost impact on affected operators.

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 this 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 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 adding the following new airworthiness 
directive:

The Boeing Company: Docket No. FAA-2021-0877; Project Identifier AD-
2020-01316-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by January 3, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-100B SUD, 747-
200B, 747-200C, 747-200F, 747-300, 747SP, 747-400, 747-400D, and 
747-400F series airplanes, certificated in any category, having line 
numbers 645 and subsequent.

(d) Subject

    Air Transport Association (ATA) of America Code 57, Wings.

[[Page 64088]]

(e) Unsafe Condition

    This AD was prompted by fuel system reviews conducted by the 
manufacturer. The FAA is issuing this AD to address arcing in the 
event of a lightning strike or high-powered short circuit, which 
could result in a fuel tank explosion or fire.

(f) Compliance

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

(g) Reconfiguration of Wire Bundle Clamps, Sealant Application, 
Installation of Clamps and Sleeves, Inspections, and Corrective Actions

    (1) For Group 1 through 9, 11, and 16 through 45 airplanes 
identified in Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 8, dated November 13, 2020: Within 60 months after the 
effective date of this AD, reconfigure the clamps of the specified 
wire bundles, apply sealant to the specified fasteners that 
penetrate the fuel tank walls, and install cushion clamps and 
polytetrafluoroethylene (TFE) sleeves on the wire bundles of the 
front spars and rear spars of the wings, as applicable, in 
accordance with Work Packages 13 through 21, as applicable, of the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 747-57-2327, Revision 8, dated November 13, 2020.
    (2) For airplanes on which the actions specified in Work Package 
7, 8, or 9 of Boeing Special Attention Service Bulletin 747-57-2327 
have been done: Within 60 months after the effective date of this 
AD: Inspect to determine if the fillet sealant identified in step 5 
of Figure 23 of Boeing Special Attention Service Bulletin 747-57-
2327, Revision 8, dated November 13, 2020, was applied to fully 
encapsulate the fastener penetrating the fuel tank; and if the 
sealant does not fully encapsulate the fastener, before further 
flight, apply sealant as specified in step 5 of Figure 23, except 
where note (f) of Figure 23 specifies to ``make sure to apply the 
fillet sealant on the fastener,'' this AD requires applying the 
fillet sealant to fully encapsulate the fastener penetrating the 
fuel tank.
    (3) For Group 2 airplanes identified in Boeing Service Bulletin 
747-57-2326, Revision 1, dated January 31, 2008: Within 60 months 
after the effective date of this AD, inspect to determine if all 
fasteners identified in Figures 4 and 5 of Boeing Service Bulletin 
747-57-2326, Revision 1, dated January 31, 2008, have been sealed; 
and if any fasteners are not sealed, before further flight, apply 
sealant in accordance with Figure 1 of Boeing Service Bulletin 747-
57-2326, Revision 1, dated January 31, 2008.

(h) Maintenance or Inspection Program Revision

    (1) For Model 747-400, 747-400D, and 747-400F series airplanes: 
Within 60 days after the effective date of this AD: Revise the 
existing maintenance or inspection program, as applicable, by 
incorporating the information in airworthiness limitations 28-AWL-
33, 28-AWL-34, and 28-AWL-37 of The Boeing Company 747-400 
Maintenance Planning Data (MPD) Document, Section 9, Airworthiness 
Limitations (AWL) and Certification Maintenance Requirements (CMRs), 
D621U400-9, Revision February 2020. The initial compliance time for 
doing the tasks is at the time specified in Boeing 747-400 MPD 
Document, Section 9, AWL and CMRs, D621U400-9, Revision February 
2020, or within 60 days after the effective date of this AD, 
whichever occurs later.
    (2) For Model 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-
300, and 747SP series airplanes: Within 60 days after the effective 
date of this AD: Revise the existing maintenance or inspection 
program, as applicable, by incorporating the information in 
airworthiness limitations 28-AWL-25, 28-AWL-27, and 28-AWL-28 of The 
Boeing Company 747-100/200/300/SP/SR Airworthiness Limitations 
(AWLs) and Certification Maintenance Requirements (CMRs), D6-13747-
CMR, Revision September 2020; except where the ``Applicability'' of 
airworthiness limitations 28-AWL-25 and 28-AWL-27 specifies ``ALL'' 
and ``NOTE,'' replace ``ALL'' and ``NOTE'' with ``Airplanes L/N 645 
and on'' and remove the ``Applicability Note'' from the Description 
column of 28-AWL-25 and 28-AWL-27. The initial compliance time for 
doing the tasks is at the time specified in The Boeing Company 
Airworthiness Limitations (AWLs) and Certification Maintenance 
Requirements (CMRs), D6-13747-CMR, Revision September 2020, or 
within 60 days after the effective date of this AD, whichever occurs 
later.

(i) No Alternative Actions, Intervals, and Critical Design 
Configuration Control Limitations (CDCCLs)

    After the maintenance or inspection program has been revised as 
required by paragraph (h)(1) or (2) of this AD, no alternative 
actions (e.g., inspections), intervals, and CDCCLs may be used 
unless the actions, intervals, and CDCCLs are approved as an 
alternative method of compliance (AMOC) in accordance with the 
procedures specified in paragraph (k) of this AD.

(j) Credit for Previous Actions

    (1) This paragraph provides credit for the Work Package 13 
actions specified in paragraph (g)(1) of this AD, if those actions 
were performed before the effective date of this AD using the 
service information specified in paragraphs (j)(1)(i) through (iv) 
of this AD.
    (i) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 4, dated August 26, 2010.
    (ii) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 5, dated September 20, 2011.
    (iii) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 6, dated February 21, 2013.
    (iv) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 7, dated November 30, 2017.
    (2) This paragraph provides credit for the Work Package 14, 15, 
and 16 actions specified in paragraph (g)(1) of this AD, if those 
actions were performed before the effective date of this AD using 
the service information specified in paragraphs (j)(2)(i) through 
(iii) of this AD.
    (i) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 5, dated September 20, 2011.
    (ii) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 6, dated February 21, 2013.
    (iii) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 7, dated November 30, 2017.
    (3) This paragraph provides credit for the Work Package 17 
actions specified in paragraph (g)(1) of this AD, if those actions 
were performed before the effective date of this AD using the 
service information specified in paragraphs (j)(3)(i) or (ii) of 
this AD.
    (i) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 6, dated February 21, 2013.
    (ii) Boeing Special Attention Service Bulletin 747-57-2327, 
Revision 7, dated November 30, 2017.
    (4) This paragraph provides credit for the Work Package 18, 19, 
and 20 actions specified in paragraph (g)(1) of this AD, if those 
actions were performed before the effective date of this AD using 
Boeing Special Attention Service Bulletin 747-57-2327, Revision 7, 
dated November 30, 2017.

(k) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO 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 responsible Flight Standards 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 (l)(1) of this AD. Information may be 
emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the responsible Flight Standards Office.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by The Boeing Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, Seattle 
ACO Branch, FAA, to make those findings. To be approved, the repair 
method, modification deviation, or alteration deviation must meet 
the certification basis of the airplane, and the approval must 
specifically refer to this AD.

(l) Related Information

    (1) For more information about this AD, contact Rose Len, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3604; email: [email protected].
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Attention: Contractual & Data Services 
(C&DS), 2600 Westminster Blvd., MC 110 SK57, Seal Beach, CA 90740-
5600;

[[Page 64089]]

telephone 562 797 1717; internet https://www.myboeingfleet.com. You 
may view this service information at the FAA, Airworthiness Products 
Section, Operational Safety Branch, 2200 South 216th St., Des 
Moines, WA. For information on the availability of this material at 
the FAA, call 206-231-3195.

    Issued on October 8, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-24834 Filed 11-16-21; 8:45 am]
BILLING CODE 4910-13-P