Airworthiness Directives; The Boeing Company Airplanes

[Federal Register Volume 89, Number 75 (Wednesday, April 17, 2024)]
[Rules and Regulations]
[Pages 27374-27376]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-08105]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1400; Project Identifier AD-2022-01374-T; 
Amendment 39-22708; AD 2024-06-03]
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 737-8 and 737-9 airplanes. This AD was 
prompted by a determination that the loss of a ground through the P6 
panel results in the failure of the standby power control unit (SPCU). 
The loss of the SPCU and ground through the P6 panel could result in 
the loss of significant flightcrew instrumentation and displays. This 
AD requires installing two bonding jumpers from the P6 panel structure 
to primary structure. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective May 22, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 22, 
2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-1400; 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 material that is incorporated by reference, 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; website myboeingfleet.com.
    <bullet> You may view this material that is incorporated by 
reference 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-2023-1400.

FOR FURTHER INFORMATION CONTACT: Raja Vengadasalam, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3537; 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 737-8 and 737-9 airplanes. The NPRM published in the 
Federal Register on August 7, 2023 (88 FR 52055). The NPRM was prompted 
by a determination that the loss of a ground through the P6 panel 
results in the failure of the SPCU. In the NPRM, the FAA proposed to 
require installing two bonding jumpers from the P6 panel structure to 
primary structure. The FAA is issuing this AD to address loss of the 
SPCU function in combination with other lost P6 functions. The unsafe 
condition, if not addressed, could result in the loss of significant 
flightcrew instruments and displays, and may lead to loss of continued 
safe flight and landing.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from United Airlines, who supported the 
NPRM without change, Boeing, the Foundation for Aviation Safety, and 
three individuals.

Request for Change to Background Paragraph

    Boeing requested that the FAA revise the description of the 
incident that prompted the NPRM. The Background section of the NPRM 
stated the following:

    During a bonding analysis, it was determined that separate 
redundant ground paths from the two ground blocks on the SPCU tray 
to airplane primary structure are required in order to prevent a 
single point of failure condition, which could result in a 
potentially confusing combination of flight deck effects and a 
combination of lost functionality.

    Boeing requested that this statement be clarified: (1) The single 
point of failure condition would result in the loss of SPCU function, 
and (2) the loss of SPCU function, in combination with other lost P6 
functions, could result in a potentially confusing combination of 
flight deck effects and lost functionality.

[[Page 27375]]

Boeing stated that the additional information would clarify and add 
detail to expand to other additional equipment in the P6.
    The FAA agrees with the suggested revision. However, the Background 
section is not repeated in this final rule in its entirety. Therefore, 
the FAA has not changed this final rule.
    The Foundation for Aviation Safety noted that the P6 panel provides 
circuit breakers for many of the airplane's most critical systems. The 
Foundation, and three individuals, requested that the FAA prohibit 
further operation of the 737 MAX.
    The FAA has determined that the corrective action mandated by this 
AD will adequately address this unsafe condition. Therefore, the FAA 
has not changed this final rule in response to these comments.

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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 737-24A1248 RB, 
dated May 16, 2022. This service information specifies procedures for 
installing new bonding jumpers from the P6 panel structure to the 
primary structure to provide a redundant ground path for the SPCU.
    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.

Costs of Compliance

    The FAA estimates that this AD affects 79 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
----------------------------------------------------------------------------------------------------------------
Install two bonding jumpers...........  3 work-hours x $85 per              $180            $435         $34,365
                                         hour = $255.
----------------------------------------------------------------------------------------------------------------

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:
2024-06-03 The Boeing Company: Amendment 39-22708; Docket No. FAA-
2023-1400; Project Identifier AD-2022-01374-T.

(a) Effective Date

    This airworthiness directive (AD) is effective May 22, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 737-8 and 737-9 
airplanes, certificated in any category, as identified in Boeing 
Alert Requirements Bulletin 737-24A1248 RB, dated May 16, 2022.

(d) Subject

    Air Transport Association (ATA) of America Code 24, Electrical 
Power.

(e) Unsafe Condition

    This AD was prompted by a determination that separate redundant 
ground paths from the two ground blocks on the standby power control 
unit (SPCU) tray to airplane primary structure are required in order 
to prevent a single point of failure condition. The FAA is issuing 
this AD to address loss of the SPCU in combination with other lost 
P6 functions. The unsafe condition, if not addressed, could result 
in the loss of significant flightcrew instruments and displays, and 
may lead to loss of continued safe flight and landing.

(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 737-24A1248 RB, dated May 16, 2022, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
737-24A1248 RB, dated May 16, 2022.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
737-24A1248, dated May 16, 2022,

[[Page 27376]]

which is referred to in Boeing Alert Requirements Bulletin 737-
24A1248 RB, dated May 16, 2022.

(h) Exceptions to Service Information Specifications

    Where the Compliance Time column of the table in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
24A1248 RB, dated May 16, 2022, refers to the original issue date of 
Requirements Bulletin 737-24A1248 RB, this AD requires using the 
effective date of this AD.

(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) 
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 Raja 
Vengadasalam, Aviation Safety Engineer, FAA, 2200 South 216th St., 
Des Moines, WA 98198; phone: 206-231-3537; 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 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) Boeing Alert Requirements Bulletin 737-24A1248 RB, dated May 
16, 2022.
    (ii) [Reserved]
    (3) For material that is incorporated by reference, 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; website myboeingfleet.com.
    (4) You may view this material that is incorporated by reference 
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/[email protected]">www.archives.gov/federal-register/cfr/[email protected].

    Issued on March 15, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-08105 Filed 4-16-24; 8:45 am]
BILLING CODE 4910-13-P

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