Document ID: FAA-2021-0099-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: The Boeing Company Airplanes
Posted Date: 2021-02-26T05:00Z

[Federal Register Volume 86, Number 37 (Friday, February 26, 2021)]
[Proposed Rules]
[Pages 11653-11656]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-03858]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0099; Project Identifier AD-2020-01272-T]
RIN 2120-AA64

Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain The Boeing Company Model 767-200, -300, -300F, and -400ER 
series airplanes. This proposed AD was prompted by significant changes 
made to the airworthiness limitations (AWLs) related to fuel tank 
ignition prevention and the nitrogen generation system. This proposed 
AD would require revising the existing maintenance or inspection 
program, as applicable, to incorporate the latest revision of the AWLs. 
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 April 12, 
2021.

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.

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-
0099; 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: Rebel Nichols, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3556; email: 
rebel.nichols@faa.gov.

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-2021-0099; Project Identifier 
AD-2020-01272-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

[[Page 11654]]

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 Rebel 
Nichols, Aerospace Engineer, Propulsion Section, FAA, Seattle ACO 
Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-
231-3556; email: rebel.nichols@faa.gov. 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, 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), Amendment 21-83 (67 FR 
72830, December 9, 2002; corrected at 68 FR 37735, June 25, 2003, to 
change ``21-82'' to ``21-83''), and Amendment 21-101 (83 FR 9162, March 
5, 2018).
    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, single failures in 
combination with another latent condition(s), and in-service failure 
experience. For all four criteria, the evaluations included 
consideration of previous actions taken that may mitigate the need for 
further action.
    This proposed AD was prompted by significant changes made to the 
AWL related to fuel tank ignition prevention and the nitrogen 
generation system. This condition, if not addressed, could result in 
the potential for ignition sources inside fuel tanks caused by latent 
failures, alterations, repairs, or maintenance actions, which, in 
combination with flammable fuel vapors, could result in a fuel tank 
explosion and consequent loss of the airplane.
    The FAA has determined that accomplishing the revision required by 
paragraph (g) of this proposed AD would terminate the following 
requirements for that airplane:
     The revision required by paragraphs (g) and (h) of AD 
2008-11-01 R1, Amendment 39-16145 (74 FR 68515, December 28, 2009).
     The revision required by paragraph (h) of AD 2010-06-10, 
Amendment 39-16234 (75 FR 15322, March 29, 2010) (AD 2010-06-10).
     The revision required by paragraph (k) of AD 2011-25-05, 
Amendment 39-16881 (77 FR 2442, January 18, 2012) (AD 2011-25-05).
     The revision required by paragraph (n) of AD 2013-25-02, 
Amendment 39-17698 (79 FR 24541, May 1, 2014) (AD 2013-25-02).
     The revision required by paragraph (g) of AD 2014-08-09, 
Amendment 39-17833 (79 FR 24546, May 1, 2014) (AD 2014-08-09).
     The revision required by paragraph (h) of AD 2014-20-02, 
Amendment 39-17975 (79 FR 59102, October 1, 2014) (AD 2014-20-02).
     The revision required by paragraphs (i)(3)(i) and (ii) of 
AD 2018-20-13, Amendment 39-19447 (83 FR 52305, October 17, 2018) (AD 
2018-20-13).

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing 767-200/300/300F/400ER Special Compliance 
Items/Airworthiness Limitations, D622T001-9-04, dated January 2020. 
This service information describes AWLs that include airworthiness 
limitation instructions (ALIs) and critical design configuration 
control limitations (CDCCLs) tasks related to fuel tank ignition 
prevention and the nitrogen generation system. 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.

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 revising the existing maintenance or 
inspection program, as applicable, to incorporate the latest revision 
of the AWLs.
    This proposed AD would require revisions to certain operator 
maintenance documents to include new actions (e.g., inspections) and 
CDCCLs. Compliance with these actions and CDCCLs is required by 14 CFR 
91.403(c). For airplanes that have been previously modified, altered, 
or repaired in the areas addressed by this proposed AD, the operator 
may not be able to accomplish the actions described in the revisions. 
In this situation, to comply with 14 CFR 91.403(c), the operator must 
request approval for an alternative method of compliance according to 
paragraph (k) of this proposed AD.

[[Page 11655]]

Costs of Compliance

    The FAA estimates that this proposed AD affects 500 airplanes of 
U.S. registry. The FAA estimates the following costs to comply with 
this proposed AD:
    The FAA has determined that revising the existing 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 FAA estimates the average total cost per 
operator to be $7,650 (90 work-hours x $85 per work-hour).

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-2021-0099; Project Identifier AD-
2020-01272-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by April 12, 2021.

(b) Affected ADs

    This AD affects the ADs specified in paragraphs (b)(1) through 
(7) of this AD.
    (1) AD 2008-11-01 R1, Amendment 39-16145 (74 FR 68515, December 
28, 2009) (AD 2008-11-01 R1).
    (2) AD 2010-06-10, Amendment 39-16234 (75 FR 15322, March 29, 
2010) (AD 2010-06-10).
    (3) AD 2011-25-05, Amendment 39-16881 (77 FR 2442, January 18, 
2012) (AD 2011-25-05).
    (4) AD 2013-25-02, Amendment 39-17698 (79 FR 24541, May 1, 2014) 
(AD 2013-25-02).
    (5) AD 2014-08-09, Amendment 39-17833 (79 FR 24546, May 1, 2014) 
(AD 2014-08-09).
    (6) AD 2014-20-02, Amendment 39-17975 (79 FR 59102, October 1, 
2014) (AD 2014-20-02).
    (7) AD 2018-20-13, Amendment 39-19447 (83 FR 52305, October 17, 
2018) (AD 2018-20-13).

(c) Applicability

    This AD applies to The Boeing Company Model 767-200, -300, -
300F, and -400ER series airplanes, certificated in any category, 
having line numbers (L/N) 1 through 1200 inclusive.

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel.

(e) Unsafe Condition

    This AD was prompted by significant changes made to the 
airworthiness limitations (AWLs) related to fuel tank ignition 
prevention and the nitrogen generation system. The FAA is issuing 
this AD to address the potential for ignition sources inside fuel 
tanks caused by latent failures, alterations, repairs, or 
maintenance actions, which, in combination with flammable fuel 
vapors, could result in a fuel tank explosion and consequent loss of 
the airplane.

(f) Compliance

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

(g) Maintenance or Inspection Program Revision

    Within 60 days after the effective date of this AD, revise the 
existing maintenance or inspection program, as applicable, to 
incorporate the information in Section A, including Subsections A.1, 
A.2, A.3, A.4, and A.5, of Boeing 767-200/300/300F/400ER Special 
Compliance Items/Airworthiness Limitations, D622T001-9-04, revision 
January 2020; except as provided by paragraph (h) of this AD. The 
initial compliance times for the airworthiness limitation 
instructions (ALI) tasks are within the applicable compliance times 
specified in paragraphs (g)(1) through (14) of this AD:
    (1) For AWL No. 28-AWL-01, ``External Wires Over Auxiliary 
(Center) Fuel Tank'': Within 144 months after the most recent 
inspection was performed as specified in AWL No. 28 AWL 01, or 
within 12 months after the effective date of this AD if no initial 
inspection has been performed or the last inspection date is 
unknown.
    (2) For AWL No. 28-AWL-05, ``Lightning Protection--Hydraulic 
Line Fuel Tank Penetration Bonding Path'': Within 25,000 flight 
hours or 72 months, whichever occurs first, since the most recent 
inspection was performed as specified in AWL No. 28-AWL-05, or 
within 30 days after the effective date of this AD if no initial 
inspection has been performed or the last inspection date is 
unknown.
    (3) For AWL No. 28-AWL-18, ``Fuel Quantity Indicating System 
(FQIS)--Out of Tank Wiring Lightning Shield to Ground Termination'': 
Within 144 months after the most recent inspection was performed as 
specified in AWL No. 28-AWL-18, or within 12 months after the 
effective date of this AD if no initial inspection has been 
performed or the last inspection date is unknown.
    (4) For AWL No. 28-AWL-20, ``Auxiliary (Center) Tank Override 
Fuel Pumps Auto Shutoff Circuit'': Within 12 months after the most 
recent inspection was performed as specified in AWL No. 28-AWL-20; 
or within 12 months after accomplishment of the actions specified in 
Boeing Service Bulletin 767-28A0083, or Boeing Service Bulletin 767-
28A0084, as applicable; whichever is later. If no initial inspection 
was performed or the last inspection date is unknown, then within 30 
days after the effective date of this AD.
    (5) For AWL No. 28-AWL-21, ``AC and DC Fuel Pump Fault Current 
Bonding Jumper Installation'': Within 72 months after the most 
recent inspection was performed as specified in AWL No. 28-AWL-21, 
or within 6 months after the effective date of this AD if no initial 
inspection has been performed or the last inspection date is 
unknown.

[[Page 11656]]

    (6) For AWL No. 28-AWL-27, ``Over-Current and Arcing Protection 
Electrical Design Features Operation--AC Fuel Pump Ground Fault 
Interrupter (GFI)'': Within 12 months after the most recent 
inspection was performed as specified in AWL No. 28-AWL-27, or 
within 12 months after accomplishment of the actions specified in 
Boeing Service Bulletin 767-28A0085, whichever is later. If no 
initial inspection was performed or the last inspection date is 
unknown, then within 30 days after the effective date of this AD.
    (7) For AWL No. 28-AWL-28, ``Auxiliary (Center) Tank Override/
Jettison Fuel Pump Failed On Protection System'': Within 12 months 
after the most recent inspection was performed as specified in AWL 
No. 28-AWL-28, or within 12 months after accomplishment of the 
actions specified in Boeing Service Bulletin 767-28A0085, whichever 
is later. If no initial inspection was performed or the last 
inspection date is unknown, then within 30 days after the effective 
date of this AD.
    (8) For AWL No. 28-AWL-35, ``Cushion Clamps and Teflon Sleeving 
Installed on Out-of-Tank Wire Bundles Installed on Brackets that are 
Mounted Directly on the Fuel Tanks'': Within 144 months after the 
most recent inspection was performed as specified in AWL No. 28-AWL-
35 or within 144 months after accomplishment of the actions 
specified in Boeing Service Bulletin 767-57A0102, whichever is 
later. If no initial inspection was performed or the last inspection 
date is unknown, then within 12 months after the effective date of 
this AD.
    (9) For AWL No. 28-AWL-37, ``FQIS BITE Test (Auxiliary (Center) 
Tank Circuit Test)'': For Model 767-300F airplanes L/N 1094 and 
subsequent, within 750 flight hours after the most recent inspection 
was performed as specified in AWL No. 28-AWL-37, or within 30 days 
after the effective date of this AD if no initial inspection has 
been performed or the last inspection date is unknown.
    (10) For AWL No. 28-AWL-38, ``Fuel Level Sensing System (FLSS) 
Dry Capacitance Test'': For Model 767-300F airplanes L/N 1096 and 
subsequent, within 750 flight hours after the most recent inspection 
was performed as specified in AWL No. 28-AWL-38, or within 30 days 
after the effective date of this AD if no initial inspection has 
been performed or the last inspection date is unknown.
    (11) For AWL No. 28-AWL-101, ``Engine Fuel Suction Feed 
Operational Test'': Within 7,500 flight hours or 36 months, 
whichever occurs first since the most recent inspection was 
performed as specified in AWL No. 28-AWL-101, or within 30 days 
after the effective date of this AD if no initial inspection has 
been performed or the last inspection date is unknown.
    (12) For AWL No. 28-AWL-102, ``Fuel Quantity Indicating System 
(FQIS)--Low Fuel and Fuel Config Indication Test'': Within 750 
flight hours after the most recent inspection was performed as 
specified in AWL No. 28-AWL-102; or within 750 flight hours after 
accomplishment of the actions specified in Boeing Service Bulletin 
767-31-0295 or Boeing Service Bulletin 767-31-0302, as applicable; 
whichever is later. If no initial inspection was performed or the 
last inspection date is unknown, then within 30 days after the 
effective date of this AD.
    (13) For AWL No. 47-AWL-04, ``Nitrogen Generation System (NGS)--
Nitrogen-Enriched Air (NEA) Distribution Ducting'': For L/N 993 and 
subsequent and all airplanes that have incorporated Boeing Service 
Bulletin 767-47-0001, within the applicable interval specified in 
AWL No. 47-AWL-04 since the most recent inspection was performed as 
specified in AWL No. 47-AWL-04. If no initial inspection was 
performed or the last inspection date is unknown, then within 4 
months after the effective date of this AD.
    (14) For AWL No. 47-AWL-05, ``Nitrogen Generation System (NGS)--
Cross Vent Check Valve'': For L/N 993 and subsequent and all 
airplanes that have incorporated Boeing Service Bulletin 767-47-
0001, within the applicable interval specified in AWL No. 47-AWL-05 
since the most recent inspection was performed as specified in AWL 
No. 47-AWL-05. If no initial inspection was performed or the last 
inspection date is unknown, then within 4 months after the effective 
date of this AD.

(h) Additional Acceptable Wire Types and Sleeving

    As an option, when accomplishing the actions required by 
paragraph (g) of this AD, the changes specified in paragraphs (h)(1) 
and (2) of this AD are acceptable.
    (1) Where AWL No. 28-AWL-09 identifies wire types BMS 13-48, BMS 
13-58, and BMS 13-60, the following acceptable wire types and cables 
can be added to AWL No. 28-AWL-09: MIL-W-22759/16, SAE AS22759/16 
(formerly M22759/16), MIL-W-22759/32, SAE AS22759/32 (formerly 
M22759/32), MIL-W-22759/34, SAE AS22759/34 (formerly M22759/34), 
MIL-W-22759/41, SAE AS22759/41 (formerly M22759/41), MIL-W-22759/86, 
SAE AS22759/86 (formerly M22759/86), MIL-W-22759/87, SAE AS22759/87 
(formerly M22759/87), MIL-W-22759/92, and SAE AS22759/92 (formerly 
M22759/92); and MIL-C-27500 and NEMA WC 27500 cables that are 
constructed from these military or SAE specification wire types, as 
applicable.
    (2) Where AWL No. 28-AWL-09 identifies TFE-2X Standard wall for 
wire sleeving, the following sleeving materials are acceptable: 
Roundit 2000NX and Varglas Type HO, HP, or HM, Grade A.

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

    After the existing maintenance or inspection program has been 
revised as required by paragraph (g) of this AD, no alternative 
actions (e.g., inspections), intervals, or 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) Terminating Action for Certain AD Requirements

    Accomplishment of the revision required by paragraph (g) of this 
AD terminates the requirements specified in paragraphs (j)(1) 
through (7) of this AD for that airplane:
    (1) The revision required by paragraphs (g) and (h) of AD 2008-
11-01 R1.
    (2) The revision required by paragraph (h) of AD 2010-06-10.
    (3) The revision required by paragraph (k) of AD 2011-25-05.
    (4) The revision required by paragraph (n) of AD 2013-25-02.
    (5) The revision required by paragraph (g) of AD 2014-08-09.
    (6) The revision required by paragraph (h) of AD 2014-20-02.
    (7) The revision required by paragraphs (i)(3)(i) and (ii) of AD 
2018-20-13.

(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: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.
    (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 Rebel Nichols, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3556; email: rebel.nichols@faa.gov.
    (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; 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 February 12, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-03858 Filed 2-25-21; 8:45 am]
BILLING CODE 4910-13-P