Rule2024-28134
Airworthiness Directives; The Boeing Company Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
December 2, 2024
Effective
January 6, 2025
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-300 and -400 series airplanes. This AD was prompted by a report that flight control rigging tolerances could result in spoiler deflection not reaching the minimal level required to engage the cruise thrust split monitor (MONFD) used by the autothrottle (A/T) system. This AD requires changing certain wire bundles, installing a new housing assembly, removing the mechanical aileron force limiter (MAFL), doing an inspection or records check to determine if certain flight control computers (FCCs) are installed, and performing applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 89 Issue 231 (Monday, December 2, 2024)</title>
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[Federal Register Volume 89, Number 231 (Monday, December 2, 2024)]
[Rules and Regulations]
[Pages 95086-95088]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-28134]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1897; Project Identifier AD-2023-00774-T;
Amendment 39-22882; AD 2024-23-03]
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 737-300 and -400 series airplanes.
This AD was prompted by a report that flight control rigging tolerances
could result in spoiler deflection not reaching the minimal level
required to engage the cruise thrust split monitor (MONFD) used by the
autothrottle (A/T) system. This AD requires changing certain wire
bundles, installing a new housing assembly, removing the mechanical
aileron force limiter (MAFL), doing an inspection or records check to
determine if certain flight control computers (FCCs) are installed, and
performing applicable on-condition actions. The FAA is issuing this AD
to address the unsafe condition on these products.
DATES: This AD is effective January 6, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of January 6,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2024-1897; 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 Blvd., MC 110-SK57, Seal Beach, CA 90740-5600;
telephone 562-797-1717; website <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
<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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2024-1897.
FOR FURTHER INFORMATION CONTACT: Eric Igama, Aviation Safety Engineer,
FAA, 2200 South 216th Street, Des Moines, WA 98198; telephone 562-627-
5388; email <a href="/cdn-cgi/l/email-protection#6614090203140f050d480f01070b072600070748010910"><span class="__cf_email__" data-cfemail="e694898283948f858dc88f81878b87a6808787c8818990">[email protected]</span></a>.
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 737-300 and -400 series airplanes. The NPRM published in
the Federal Register on July 29, 2024 (89 FR 60836). The NPRM was
prompted by a report indicating that flight control rigging tolerances
could result in spoiler deflection not reaching the minimal level
required to engage the MONFD used by the A/T system. In the NPRM, the
FAA proposed to require changing certain wire bundles, installing a new
housing assembly, removing the mechanical aileron force limiter (MAFL),
doing an inspection or records check to determine if certain flight
control computers (FCCs) are installed, and performing applicable on-
condition actions. The FAA is issuing this AD to address failure of the
spoiler deflection to engage the MONFD, which could lead to significant
throttle split, leading to asymmetric thrust and the subsequent lack of
autothrottle disengagement, uncommanded roll, and consequent loss of
control of the airplane and reduced ability of the flightcrew to
maintain the safe flight and landing of the airplane.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from Aviation Partners Boeing. The
following presents the comment received on the NPRM and the FAA's
response.
Effect of Winglets on Accomplishment of the Proposed Actions
Aviation Partners Boeing stated that the installation of winglets
per Supplemental Type Certificate (STC) ST01219SE does not affect
compliance with the proposed actions.
The FAA agrees with the commenter that STC ST01219SE does not
affect the accomplishment of the manufacturer's service instructions.
Therefore, the installation of STC ST01219SE does not affect the
ability to accomplish the actions required by this AD. The FAA has not
changed this AD in this regard.
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, 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 737-22A1399 RB,
dated April 13, 2023. This material specifies procedures for changing
certain wire bundles, installing a new housing assembly, removing the
MAFL, doing an inspection or records check to determine if certain FCCs
are installed (FCCs that have an electronic aileron limiter (EAL)
revision), and performing applicable on-condition actions. On-condition
actions include installing new FCCs or re-installing kept FCCs (the
installation includes doing specified tests and applicable corrective
actions until the tests are passed).
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 110 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
[[Page 95087]]
Estimated Costs
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Action Labor cost Parts cost Cost per product Cost on U.S. operators
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Wire bundle change, MAFL Up to 10 work- $0 Up to $850............. Up to $93,500.
removal, housing assembly hours x $85 per
installation, and inspection/ hour = up to
records review. $850.
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The FAA estimates the following costs to do any on-condition
actions that would be required based on the results of the inspection/
records review. The agency has no way of determining the number of
aircraft that might need these on-condition actions:
On-Condition Costs
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Cost per
Action Labor cost Parts cost product
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Installation of FCCs......................... 2 work-hours x $85 per hour = $7,250 $7,420
$170.
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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:
2024-23-03 The Boeing Company: Amendment 39-22882; Docket No. FAA-
2024-1897; Project Identifier AD-2023-00774-T.
(a) Effective Date
This airworthiness directive (AD) is effective January 6, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 737-300 and -400
series airplanes, certificated in any category, as identified in
Boeing Alert Requirements Bulletin 737-22A1399 RB, dated April 13,
2023.
(d) Subject
Air Transport Association (ATA) of America Code 27, Flight
controls.
(e) Unsafe Condition
This AD was prompted by a report that flight control rigging
tolerances could result in spoiler deflection not reaching the
minimal level required to engage the cruise thrust split monitor
(MONFD) used by the autothrottle (A/T) system. The FAA is issuing
this AD to address failure of the spoiler deflection to engage the
MONFD. The unsafe condition, if not addressed, could lead to
significant throttle split, leading to asymmetric thrust and the
subsequent lack of autothrottle disengagement, which could result in
an uncommanded roll and consequent loss of control of the airplane,
and reduced ability of the flightcrew to maintain the safe flight
and landing 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 737-22A1399 RB, dated April 13, 2023, do
all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
737-22A1399 RB, dated April 13, 2023.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
737-22A1399, dated April 13, 2023, which is referred to in Boeing
Alert Requirements Bulletin 737-22A1399 RB, dated April 13, 2023.
(h) Exceptions to Requirements Bulletin Specifications
Where the Compliance Time columns of the table in the
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
22A1399 RB, dated April 13, 2023, use the phrase ``the original
issue date of Requirements Bulletin 737-22A1399 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,
[[Page 95088]]
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: <a href="/cdn-cgi/l/email-protection#5e1f13111d1e383f3f70393128"><span class="__cf_email__" data-cfemail="4c0d01030f0c2a2d2d622b233a">[email protected]</span></a>.
(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 Eric Igama,
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines,
WA 98198; phone: 562-627-5388; email: <a href="/cdn-cgi/l/email-protection#d8aab7bcbdaab1bbb3f6b1bfb9b5b998beb9b9f6bfb7ae"><span class="__cf_email__" data-cfemail="483a272c2d3a212b2366212f292529082e2929662f273e">[email protected]</span></a>.
(2) Material 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 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 737-22A1399 RB, dated
April 13, 2023.
(ii) [Reserved]
(3) For the material 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; website <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
(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 <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#abcdd985c2c5d8dbcec8dfc2c4c5ebc5cad9ca85ccc4dd"><span class="__cf_email__" data-cfemail="ea8c98c48384999a8f899e838584aa848b988bc48d859c">[email protected]</span></a>.
Issued on November 7, 2024.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2024-28134 Filed 11-29-24; 8:45 am]
BILLING CODE 4910-13-P
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