[Federal Register Volume 90, Number 26 (Monday, February 10, 2025)]
[Rules and Regulations]
[Pages 9209-9211]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-02383]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1467; Project Identifier AD-2023-01241-T;
Amendment 39-22935; AD 2025-02-02]
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 all
The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500
series airplanes. This AD was prompted by a report indicating cracks in
the frame inner chord and web at station (STA) 727. This AD requires an
inspection for any repair installed, repetitive inspections of the
frame inner chord and web at STA 727 for any crack, and applicable on-
condition actions. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective March 17, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 17,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-1467; 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-2024-1467.
FOR FURTHER INFORMATION CONTACT: Muoi Vuong, Aviation Safety Engineer,
FAA, 2200 South 216th Street, Des Moines, WA 98198; telephone: 562-627-
5205; 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 all The Boeing Company
Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. The
NPRM published in the Federal Register on May 20, 2024 (89 FR 43792).
The NPRM was prompted by a report indicating cracks in the frame inner
chord and web at STA 727 between S-11L and S-13L. In the NPRM, the FAA
proposed to require an inspection for any repair installed, repetitive
inspections of the frame inner chord and web at STA 727 for any crack,
and applicable on-condition actions. The FAA is issuing this AD to
address cracks in the left and right frames at STA 727 before they
reach a critical length. The unsafe condition, if not addressed, may
result in the inability of a principal structural element to sustain
limit load, which could adversely affect the structural integrity of
the airplane.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from three commenters, including Aviation
Partners Boeing, FlyPersia Airline, and Sudan Civil Aviation Authority.
In addition, the FAA received a comment from an individual whose
request is not specific to this AD or a request the FAA can act on.
This comment is outside the scope of this rulemaking. The following
presents the comments received on the NPRM and the FAA's response to
each comment.
Effect of Winglets on Accomplishment of the Proposed Actions
Aviation Partners Boeing stated that the installation of winglets
per the Supplemental Type Certificate (STC) ST01219SE does not affect
the actions specified in the proposed AD.
The FAA agrees with the commenter. The FAA has redesignated
paragraph (c) of the proposed AD as paragraph (c)(1) of this AD and
added paragraph (c)(2) to this AD to state that installation of STC
ST01219SE does not affect the ability to accomplish the actions
required by this AD. Therefore, for airplanes on which STC ST01219SE is
installed, a ``change in product'' alternative method of compliance
(AMOC) approval request is not necessary to comply with the
requirements of 14 CFR 39.17.
Request To Expand the Area of Inspection
FlyPersia Airline requested that the area of inspection for any
repair and repetitive high frequency eddy current inspection include
the frame inner chord and web at STA 663.75 through STA 727 between
stringers S-11 and S-13 left and right sides. The commenter stated that
the mentioned crack on stringers S-11 and S-13 left and right might
also exist on those stringers at STA 663.75 through STA 727, because on
Model 737-300 airplanes there is a landing gear cavity, which impresses
circumferential structure unity on STA 663.75.
[[Page 9210]]
The FAA disagrees with expanding the area of inspection in this AD.
The Boeing service bulletin addresses only the frame inner chord and
web at STA 727, between S-11 and S-13, left and right sides. STA 727
frame between S-11 and S-13, located at a bulkhead station, is
different from other frames forward of STA 727, and therefore is the
only area of inspection addressed in this AD. However, if additional
data are presented that would justify extending the subject inspection
area, the FAA might consider further rulemaking on this issue. No
change has been made to this AD regarding this issue.
Request To Reduce the Proposed Grace Period for the Initial Compliance
Time
Sudan Civil Aviation Authority requested the grace period for the
initial compliance time for the general visual inspection of STA 727
(within 4,500 flight cycles after the original issue date of the
requirements bulletin) be reduced. Sudan Civil Aviation Authority
stated that the compliance time for some Model 737-400 airplanes may
fall beyond the 50,000 total flight cycles at which the crack has been
found.
The FAA disagrees. After considering all the available information,
the FAA has determined that the grace period, as proposed, represents
an appropriate interval of time in which the required actions can be
performed in a timely manner within the affected fleet, while still
maintaining an adequate level of safety. In developing an appropriate
grace period, the FAA considered the safety implications, parts
availability, normal maintenance schedules, and the manufacturer's
recommendation for timely accomplishment of the modifications. To
reduce the grace period of the proposed AD would necessitate (under the
provisions of the Administrative Procedure Act) reissuing the notice,
reopening the period for public comment, considering additional
comments subsequently received, and eventually issuing a final rule. In
light of this, and in consideration of the amount of time that has
already elapsed since issuance of the original notice, the FAA has
determined that further delay of this AD is not appropriate. However,
if additional data are presented that would justify a shorter
compliance time, the FAA may consider further rulemaking on this issue.
No change has been made to this AD regarding this issue.
Request To Revise Requirements Bulletin To Delete Condition 2.2
Sudan Civil Aviation Authority stated that Condition 2.2: No Crack
Found in Group 2, Table 1: Inspection of Frame at STA 727 Between S-11
and S-13, Left and Right Side, 3. Compliance, of Boeing Alert
Requirements Bulletin 737-53A1416RB, dated July 21, 2023, needs to be
deleted. The commenter pointed out that Condition 2.2 (unrepaired
areas) should be deleted because there is no repair found.
The FAA agrees to clarify. Condition 2 is accomplished for
airplanes that have no repairs in the inspection area and requires high
frequency eddy current (HFEC) inspections of the area before further
flight. Condition 2.2 is then accomplished if no crack is found during
the initial inspection (Condition 2), repeating the HFEC inspections of
the unrepaired areas within 9,000 flight cycles. Condition 2.2 includes
footnote (a) because a repair could be installed at any point prior to
the repeat HFEC inspection, and that repair could terminate the repeat
HFEC inspection. No change has been made to this AD regarding this
issue.
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 737-53A1416 RB,
dated July 21, 2023. This material specifies procedures for a general
visual inspection for any repair and repetitive high frequency eddy
current inspections of the frame inner chord and web at STA 727,
between S-11 and S-13, left and right sides, for any crack, and
applicable on-condition actions. On-condition actions include obtaining
and following repair instructions. 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 245 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspections......................... 8 work-hours x $85 per $0 $680 $166,600
hour = $680.
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The FAA has received no definitive data on which to base the cost
estimates for the on-condition actions specified in this AD.
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:
[[Page 9211]]
(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:
2025-02-02 The Boeing Company: Amendment 39-22935; Docket No. FAA-
2024-1467; Project Identifier AD-2023-01241-T.
(a) Effective Date
This airworthiness directive (AD) is effective March 17, 2025.
(b) Affected ADs
None.
(c) Applicability
(1) This AD applies to all The Boeing Company Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes, certificated in
any category.
(2) Installation of Supplemental Type Certificate (STC)
ST01219SE does not affect the ability to accomplish the actions
required by this AD. Therefore, for airplanes on which STC ST01219SE
is installed, a ``change in product'' alternative method of
compliance (AMOC) approval request is not necessary to comply with
the requirements of 14 CFR 39.17.
(d) Subject
Air Transport Association (ATA) of America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by a report indicating cracks in the frame
inner chord and web at station (STA) 727. The FAA is issuing this AD
to address cracks in the left and right frames at STA 727 before
they reach a critical length. The unsafe condition, if not
addressed, may result in the inability of a principal structural
element to sustain limit load, which could adversely affect the
structural integrity of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions for Group 1 Airplanes
For airplanes identified as Group 1 in Boeing Alert Requirements
Bulletin 737-53A1416 RB, dated July 21, 2023: Within 120 days after
the effective date of this AD, inspect for existing repairs and
cracking of the frame inner chord and web at STA 727, between S-11
and S-13, left and right sides, using a method approved in
accordance with the procedures specified in paragraph (j) of this
AD.
(h) Required Actions for Group 2 Airplanes
For airplanes identified as Group 2 in Boeing Alert Requirements
Bulletin 737-53A1416 RB, dated July 21, 2023: Except as specified by
paragraph (i) of this AD, at the applicable times specified in the
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
53A1416 RB, dated July 21, 2023, do all applicable actions
identified in, and in accordance with, the Accomplishment
Instructions of Boeing Alert Requirements Bulletin 737-53A1416 RB,
dated July 21, 2023.
Note 1 to paragraph (h): Guidance for accomplishing the actions
required by this AD can be found in Boeing Service Bulletin 737-
53A1416, dated July 21, 2023, which is referred to in Boeing Alert
Requirements Bulletin 737-53A1416 RB, dated July 21, 2023.
(i) Exceptions to Requirements Bulletin Specifications
(1) Where the Compliance Time columns of the tables in the
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
53A1416 RB, dated July 21, 2023, refers to the original issue date
of Boeing Alert Requirements Bulletin 737-53A1416 RB, this AD
requires using the effective date of this AD.
(2) Where Boeing Alert Requirements Bulletin 737-53A1416 RB,
dated July 21, 2023, specifies contacting Boeing for repair
instructions or for alternative inspections, this AD requires doing
the repair, or doing the alternative inspections and applicable on-
condition actions, before further flight using a method approved in
accordance with the procedures specified in paragraph (j) of this
AD.
(j) Alternative Methods of Compliance
(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 Muoi Vuong,
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines,
WA 98198; telephone: 562-627-5205; 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 737-53A1416 RB, dated
July 21, 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/ibr-locations or email [email protected].
Issued on January 14, 2025.
Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-02383 Filed 2-7-25; 8:45 am]
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