[Federal Register Volume 89, Number 179 (Monday, September 16, 2024)]
[Rules and Regulations]
[Pages 75462-75464]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-20834]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-1000; Project Identifier AD-2023-01051-T; 
Amendment 39-22809; AD 2024-16-03]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 747-400F series airplanes. This AD was 
prompted by a report that cap seals were not applied to certain 
fasteners in the fuel tanks during production. This AD requires 
applying cap seals to certain fastener collars inside the fuel tanks. 
The FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective October 21, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 21, 
2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-1000; 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.
    Material Incorporated by Reference:
     For Boeing material identified in this AD, contact Boeing 
Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 
2600 Westminster Boulevard, MC 110-SK57, Seal Beach, CA 90740-5600; 
telephone 562-797-1717; website myboeingfleet.com.
     You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th Street, 
Des Moines, WA. For information on the availability of this material at 
the FAA, call 206-231-3195. It is also available at regulations.gov 
under Docket No. FAA-2024-1000.

FOR FURTHER INFORMATION CONTACT: Samuel Dorsey, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; telephone 
206-231-3415; 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 certain The Boeing 
Company Model 747-400F series airplanes. The NPRM published in the 
Federal Register on April 12, 2024 (89 FR 25823). The NPRM was prompted 
by a report indicating that cap seals were not applied to certain 
fasteners in the fuel tank during production. The FAA issued AD 2022-
10-11, Amendment 39-22049 (87 FR 34120, June 6, 2022) to require, among 
other actions, application of cap seals to certain fasteners in the 
fuel tank on airplanes having line numbers 645 through 1363 inclusive. 
Cap seals were determined to be a necessary feature by SFAR 88 reviews 
and were required to be

[[Page 75463]]

retrofitted onto existing airplanes by AD 2022-10-11 and earlier ADs. 
Boeing intended to incorporate similar changes on future airplanes, 
ultimately those having line numbers 1364 through 1419 inclusive, via a 
production design change. However, Boeing discovered that the design 
change omitted application of the cap seals on eight fasteners (four 
each on the left and right wings in the inboard main fuel tanks). 
Without these cap seals, the ends of the fasteners do not have 
sufficient electrical insulation to prevent arcing in the event of a 
lightning strike or high-powered short circuit, possibly creating an 
ignition source in the inboard main fuel tanks. A failure to prevent 
possible ignition sources in the fuel tank, in combination with 
flammable fuel vapors, could result in an explosion or fire and 
consequent loss of the airplane. In the NPRM, the FAA proposed to 
require applying cap seals to certain fastener collars inside the fuel 
tanks. The FAA is issuing this AD to address the unsafe condition on 
these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from Air Line Pilots Association, 
International (ALPA) and an individual who supported the NPRM without 
change. The FAA also received an additional four comments from 
individuals who had no objection to the NPRM. One commenter expressed 
concern about the effect on safety of certain internal Boeing 
practices. This comment is outside the scope of the NPRM.
    The FAA received an additional comment from Boeing. The following 
presents that comment and the FAA's response.

Request for Clarification of Sealant Part Number

    Boeing requested an exception be added to paragraph (h) of the 
proposed AD to correct an incorrect part number listed in the service 
bulletin for the sealant. Boeing Alert Requirements Bulletin 747-
57A2371 RB, dated September 29, 2023, inadvertently specifies the 
application of sealant Boeing Material Specification (BMS) 5-45, CLASS 
B-2, GRADE 1, for certain required actions. GRADE 1 does not apply to 
the specification noted. Boeing informed customers of this 
typographical error via Information Notice 747-57A2371 IN-01 dated May 
20, 2024.
    The FAA agrees and has added an exception in paragraph (h)(2) of 
this AD to correct the typographical error. As stated by Boeing, Class 
B BMS 5-45 sealant does not have an additional grade identifier. Only 
Class A BMS 5-45 sealant possesses a grade identifier.

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.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 747-57A2371 RB, 
dated September 29, 2023. This material specifies procedures for 
applying cap seals to four fastener collars inside the fuel tank common 
to the stiffeners located at the front spar on the left and right 
wings. This material 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.

Costs of Compliance

    The FAA estimates that this AD affects 15 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Apply cap seals.......................  37 work-hours x $85 per           $1,000          $4,145         $62,175
                                         hour = $3,145.
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    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some or all of the costs of 
this 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

    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.

[[Page 75464]]

Sec.  39.13  [Amended]

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

2024-16-03 The Boeing Company: Amendment 39-22809; Docket No. FAA-
2024-1000; Project Identifier AD-2023-01051-T.

(a) Effective Date

    This airworthiness directive (AD) is effective.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 747-400F series 
airplanes, certificated in any category, as identified in Boeing 
Alert Requirements Bulletin 747-57A2371 RB, dated September 29, 
2023.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report that cap seals were not applied 
to certain fasteners in the fuel tanks during production. The FAA is 
issuing this AD to address missing cap seals in the fuel tanks. The 
unsafe condition, if not addressed, could result in a failure to 
prevent possible ignition sources in the fuel tanks, which in 
combination with flammable fuel vapors, could result in an explosion 
or fire and consequent loss of the airplane.

(f) Compliance

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

(g) Required Actions

    Except as specified by paragraph (h) of this AD: At the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 747-57A2371 RB, dated September 29, 
2023, do all applicable actions identified in, and in accordance 
with, the Accomplishment Instructions of Boeing Alert Requirements 
Bulletin 747-57A2371 RB, dated September 29, 2023.

    Note 1 to paragraph (g):  Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
747-57A2371, dated September 29, 2023, which is referred to in 
Boeing Alert Requirements Bulletin 747-57A2371 RB, dated September 
29, 2023.

(h) Exceptions to Service Information Specifications

    (1) Where Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 747-
57A2371 RB, dated September 29, 2023, use the phrase ``the original 
issue date of Requirements Bulletin 747-57A2371 RB,'' this AD 
requires using the effective date of this AD.
    (2) Where Boeing Alert Requirements Bulletin 747-57A2371 RB, 
dated September 29, 2023, states ``BMS 5-45, CLASS B-2, GRADE 1,'' 
this AD requires replacing that text with ``BMS 5-45, CLASS B-2.''

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, AIR-520, Continued Operational Safety 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 
(j)(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, AIR-
520, Continued Operational Safety 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.

(j) Related Information

    (1) For more information about this AD, contact Samuel Dorsey, 
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, 
WA 98198; telephone 206-231-3415; email [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the address specified in 
paragraph (k)(3) of this AD.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the material listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (i) Boeing Alert Requirements Bulletin 747-57A2371 RB, dated 
September 29, 2023.
    (ii) [Reserved]
    (3) For Boeing material identified in this AD, contact Boeing 
Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 
2600 Westminster Boulevard, MC 110-SK57, Seal Beach, CA 90740-5600; 
telephone 562-797-1717; website myboeingfleet.com.
    (4) You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th 
Street, Des Moines, WA. For information on the availability of this 
material at the FAA, call 206-231-3195.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/[email protected]">www.archives.gov/federal-register/cfr/[email protected].

    Issued on July 30, 2024.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2024-20834 Filed 9-13-24; 8:45 am]
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