Airworthiness Directives; The Boeing Company Airplanes

[Federal Register Volume 89, Number 175 (Tuesday, September 10, 2024)]
[Rules and Regulations]
[Pages 73269-73271]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-20390]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-0761; Project Identifier AD-2023-01256-T; 
Amendment 39-22798; AD 2024-15-07]
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 777 airplanes. This AD was prompted by 
a determination that the nitrogen enriched air distribution system 
(NEADS) cover plate assembly attached to a certain vent stringer in the 
center wing tank was installed without a designed electrical bond. This 
AD requires installing electrical bonding and grounding, installing the 
cover plate assembly with new fasteners, and revising the existing 
maintenance or inspection program, as applicable, to incorporate new 
airworthiness limitations. The FAA is issuing this AD to address the 
unsafe condition on these products.

DATES: This AD is effective October 15, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 15, 
2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-0761; 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:
    <bullet> 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.
    <bullet> You may view this material 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. It is also available at regulations.gov under 
Docket No. FAA-2024-0761.

FOR FURTHER INFORMATION CONTACT: Anthony Decaro, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone: 
562-627-5374; 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 777 airplanes. The NPRM published in the Federal Register 
on March 25, 2024 (89 FR 20555). The NPRM was prompted by a report 
indicating a production audit by the design approval holder found that 
the design of the NEADS cover plate assembly did not comply with the 
requirements for nitrogen generation system certification (14 CFR 
25.981). It was discovered that the NEADS cover plate assembly attached 
to a certain vent stringer in the center wing tank was installed 
without a designed electrical bond for electrostatic dissipation. In 
the NPRM, the FAA proposed to require installing electrical bonding and 
grounding, installing the cover plate assembly with new fasteners, and 
revising the existing maintenance or inspection program, as applicable, 
to incorporate new airworthiness limitations. The FAA is issuing this 
AD to address the accumulation of electrostatic charge in the cover 
plate assembly and float valve assembly during airplane refueling, 
which could lead to electrostatic discharge to the surrounding 
structure. The unsafe condition, if not addressed, could result in 
result in an ignition source inside the fuel tank and subsequent fire 
or explosion.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from the Air Line Pilots Association, 
International (ALPA) who supported the NPRM without change and a 
comment from United Airlines who reviewed the

[[Page 73270]]

NPRM and provided no additional comment. The FAA received an additional 
comment from Boeing. The following presents the comment received on the 
NPRM and the FAA's response to that comment.

Request To Clarify the Unsafe Condition

    Boeing requested the unsafe condition be revised to clarify when 
the accumulation of electrostatic charge on the vent float valve 
assembly could occur. Specifically, Boeing requested adding the words 
``during airplane refueling'' to the unsafe condition because the 
threat of accumulation is only present during refueling operation when 
charged fuel is introduced to the fuel tank from the airport refueling 
infrastructure, and that other airplane operations such as flight do 
not introduce a threat to the installation.
    The FAA agrees with clarifying the unsafe condition. The FAA has 
revised the Background section and paragraph (e) to clarify that the 
FAA is issuing this AD to address the accumulation of electrostatic 
charge in the cover plate assembly and float valve assembly during 
airplane refueling, which could lead to electrostatic discharge to the 
surrounding structure.

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 777-47A0007 RB, 
dated November 21, 2023. This material specifies procedures for 
removing the cover plate assembly and its attached float valve 
assembly, installing electrical bonding and grounding, measuring the 
bonding resistance between the bolt heads/cover plate assembly/float 
valve assembly mounting flange and the vent stringer No. 15 and between 
the nuts and the cover plate assembly, and installing the cover plate 
assembly with new fasteners. This material also specifies revising the 
operator's maintenance or inspection program, as applicable, by 
incorporating new airworthiness limitations (AWLs). 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 292 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
----------------------------------------------------------------------------------------------------------------
Electrical bond installation..........  27 work-hours x $85 per              $93          $2,388        $697,296
                                         hour = $2,295.
----------------------------------------------------------------------------------------------------------------

    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 agency 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

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:
2024-15-07 The Boeing Company: Amendment 39-22798; Docket No. FAA-
2024-0761; Project Identifier AD-2023-01256-T.

(a) Effective Date

    This airworthiness directive (AD) is effective October 15, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 777-200, -200LR, -
300, -300ER, and 777F series airplanes, certificated in any 
category, as identified in Boeing Alert

[[Page 73271]]

Requirements Bulletin 777-47A0007 RB, dated November 21, 2023.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a determination that the nitrogen 
enriched air distribution system (NEADS) cover plate assembly 
attached to vent stringer No. 15 in the center wing tank was 
installed without a designed electrical bond. The FAA is issuing 
this AD to address the accumulation of electrostatic charge in the 
cover plate assembly and float valve assembly during airplane 
refueling, which could lead to electrostatic discharge to the 
surrounding structure. The unsafe condition, if not addressed, could 
result in an ignition source inside the fuel tank and subsequent 
fire or explosion.

(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 777-47A0007 RB, dated November 21, 2023, 
do all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
777-47A0007 RB, dated November 21, 2023.

    Note 1 to paragraph (g):  Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
777-47A0007, dated November 21, 2023, which is referred to in Boeing 
Alert Requirements Bulletin 777-47A0007 RB, dated November 21, 2023.

(h) Exceptions to Service Information Specifications

    (1) Where the ``Effectivity'' paragraph and Compliance Time 
columns of the tables in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 777-47A0007 RB, dated November 21, 2023, 
refer to the original issue date of Requirements Bulletin 777-
47A0007 RB, this AD requires using the effective date of this AD.
    (2) Where the compliance time for ``ACTION 3: Incorporate 
Maintenance Planning Data (MPD),'' in the ``Compliance'' paragraph 
of Boeing Alert Requirements Bulletin 777-47A0007 RB, dated November 
21, 2023, refers to before further flight after accomplishing ACTION 
1 and ACTION 2, this AD requires incorporating the MPD within 60 
days after the effective date of this AD.

(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 (j) of this AD.

(j) 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 
(k)(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.

(k) Related Information

    (1) For more information about this AD, contact Anthony Decaro, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; telephone: 562-627-5374; email: [email protected].
    (2) Material identified in this AD that is not incorporated by 
reference is available at the address specified in paragraph (l)(3) 
of this AD.

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference 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 777-47A0007 RB, dated 
November 21, 2023.
    (ii) [Reserved]
    (3) For this material, 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 St., 
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/ibr-locations or email [email protected].

    Issued on September 5, 2024.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2024-20390 Filed 9-9-24; 8:45 am]
BILLING CODE 4910-13-P

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