Proposed Rule2022-24244
Airworthiness Directives; The Boeing Company Model 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
November 9, 2022
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This proposed AD was prompted by an evaluation by the design approval holder (DAH) indicating that the skin lap splice at certain stringers is subject to widespread fatigue damage (WFD). This proposed AD would require an inspection for any repair at certain skin lap splices and depending on the configuration, repetitive inspections for buckling, wrinkling, bulging at affected skin lap splices and repair, repetitive inspections for cracking at affected locations common to fuselage skin on the left and right sides and repair, and alternative inspections and on-condition actions. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 87 Issue 216 (Wednesday, November 9, 2022)</title>
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[Federal Register Volume 87, Number 216 (Wednesday, November 9, 2022)]
[Proposed Rules]
[Pages 67581-67584]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-24244]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-1250; Project Identifier AD-2022-00763-T]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Model Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and
-900ER series airplanes. This proposed AD was prompted by an evaluation
by the design approval holder (DAH) indicating that the skin lap splice
at certain stringers is subject to widespread fatigue damage (WFD).
This proposed AD would require an inspection for any repair at certain
skin lap splices and depending on the configuration, repetitive
inspections for buckling, wrinkling, bulging at affected skin lap
splices and repair, repetitive inspections for cracking at affected
locations common to fuselage skin on the left and right sides and
repair, and alternative inspections and on-condition actions. The FAA
is proposing this AD to address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by December
27, 2022.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
[[Page 67582]]
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building, Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
<bullet> Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this NPRM, 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; internet <a href="http://myboeingfleet.com">myboeingfleet.com</a>. You may view this
referenced service information 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> by searching
for and locating Docket No. FAA-2022-1250.
Examining the AD Docket
You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> by searching for
and locating Docket No. FAA-2022-1250; 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 NPRM, any comments
received, and other information. The street address for Docket
Operations is listed above.
FOR FURTHER INFORMATION CONTACT: Willard Ashforth, Senior Aerospace
Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th
St., Des Moines, WA 98198; phone: 206-231-3520; email:
<a href="/cdn-cgi/l/email-protection#debcb7b2b2f0bfadb6b8b1acaab69eb8bfbff0b9b1a8"><span class="__cf_email__" data-cfemail="c3a1aaafafeda2b0aba5acb1b7ab83a5a2a2eda4acb5">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2022-1250; Project Identifier
AD-2022-00763-T'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
<a href="http://regulations.gov">regulations.gov</a>, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to
Willard Ashforth, Senior Aerospace Engineer, Airframe Section, FAA,
Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone:
206-231-3520; email: <a href="/cdn-cgi/l/email-protection#87e5eeebeba9e6f4efe1e8f5f3efc7e1e6e6a9e0e8f1"><span class="__cf_email__" data-cfemail="b8dad1d4d496d9cbd0ded7caccd0f8ded9d996dfd7ce">[email protected]</span></a>. A. Any commentary that the
FAA receives that is not specifically designated as CBI will be placed
in the public docket for this rulemaking.
Background
Fatigue damage can occur locally, in small areas or structural
design details, or globally, in widespread areas. Multiple-site damage
is widespread damage that occurs in a large structural element such as
a single rivet line of a lap splice joining two large skin panels.
Widespread damage can also occur in multiple elements such as adjacent
frames or stringers. Multiple-site damage and multiple-element damage
cracks are typically too small initially to be reliably detected with
normal inspection methods. Without intervention, these cracks will
grow, and eventually compromise the structural integrity of the
airplane. This condition is known as WFD. It is associated with general
degradation of large areas of structure with similar structural details
and stress levels. As an airplane ages, WFD will likely occur, and will
certainly occur if the airplane is operated long enough without any
intervention.
An FAA final rule (``Aging Airplane Program: Widespread Fatigue
Damage;'' 75 FR 69746, November 15, 2010) became effective on January
14, 2011, and amended 14 CFR parts 25, 26, 121, and 129 (commonly known
as the WFD rule). The WFD rule requires certain actions to prevent
structural failure due to WFD throughout the operational life of
certain existing transport category airplanes and all of these
airplanes that will be certificated in the future. Design approval
holders (DAHs) of existing and future airplanes subject to the WFD rule
are required to establish a limit of validity (LOV) of the engineering
data that support the structural maintenance program. Operators
affected by the WFD rule may not fly an airplane beyond its LOV, unless
an extended LOV is approved.
The WFD rule does not require identifying and developing
maintenance actions if the DAHs can show that such actions are not
necessary to prevent WFD before the airplane reaches the LOV. Many
LOVs, however, do depend on accomplishment of future maintenance
actions. As stated in the WFD rule, any maintenance actions necessary
to reach the LOV will be mandated by airworthiness directives through
separate rulemaking actions.
In the context of WFD, this action is necessary to enable DAHs to
propose LOVs that allow operators the longest operational lives for
their airplanes, and still ensure that WFD will not occur. This
approach allows for an implementation strategy that provides
flexibility to DAHs in determining the timing of service information
development (with FAA approval), while providing operators with
certainty regarding the LOV applicable to their airplanes.
The FAA has received reports indicating fuselage skin cracking
found between stations (STA) 767 and STA 787, just below S-14R fuselage
skin lap splice, where a lower skin panel buckle intersected the upper
skin of the lap splice. Fuselage skin cracking was also found between
just below S-14R between STA 747 and STA 767. Skin buckles, wrinkles,
or bulges may be precursors to cracks at the potential affected
fuselage longitudinal lap splice areas on all 737NG airplanes. Fatigue
cracks initiated at multiple locations where linear anomalies were
found in the clad layer of the lower skin. Areas of loose paint,
discoloration, loose fasteners, lap joint separation, or disturbed
sealant can be indicative of areas where skin buckles, wrinkles, or
bulges have occurred. Such areas should
[[Page 67583]]
be carefully examined for skin deformation; however, skin buckles,
wrinkles, or bulges may also exist without other signs of skin
distress. This condition was the result of incorrect procedures used to
install lap splice during airplane production. This condition, if not
addressed, could result in any small crack, any buckle, any wrinkle or
any bulge in the fuselage skin lap splice may go undetected. Continued
operation of the airplane with any undetected small crack, buckle,
wrinkle or bulge in the fuselage skin lap splice could cause a large
crack in the fuselage skin, which may result in the inability of a
principal structural element to sustain limit load, which could result
in reduce structural integrity of the airplane and lead to a
decompression event.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Special Attention Requirements Bulletin
737-53-1399 RB, dated May 20, 2022. This service information specifies
procedures for a general visual inspection for any repair, any buckle,
any wrinkle, any bulge, and any cracking at skin lap splice at
stringers S-4 (Boeing Converted Freighter only), S-14 and S-24 (737-600
only). This service information also describes procedures, depending on
the configuration, for repetitive detailed inspections for buckling,
wrinkling, bulging at unrepaired areas of affected lap splices and
repair; repetitive detailed, high frequency eddy current (HFEC), and
ultrasonic (UT) inspections for cracking at affected locations common
to fuselage skin on the left and right sides and repair; and
alternative inspections and on-condition actions.
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.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in the service information already described except for any differences
identified as exceptions in the regulatory text of this proposed AD.
For information on the procedures and compliance times, see this
service information at <a href="http://regulations.gov">regulations.gov</a> by searching for and locating
Docket No. FAA-2022-1250.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 2,462 airplanes of U.S. registry. The FAA estimates the
following costs to comply with this proposed AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Inspections...................... Up to 34 hours x $0 $2,890 per Up to $7,115,180
$85 per hour = Up inspection cycle. per inspection
to $2,890 per cycle.
inspection cycle.
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The FAA has received no definitive data on which to base the cost
estimates for the on-condition repairs or for the alternative
inspections and on-condition actions specified in this proposed 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
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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:
The Boeing Company: Docket No. FAA-2022-1250; Project Identifier AD-
2022-00763-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by December 27, 2022
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 737-600, -700, -
700C, -800, -900, and -900ER series airplanes, certificated in any
category.
(d) Subject
Air Transport Association (ATA) of America Code 53, Fuselage.
[[Page 67584]]
(e) Unsafe Condition
This AD was prompted by an evaluation by the design approval
holder (DAH) indicating that the skin lap splice at stringers S-4,
S-14, and S-24 are subject to widespread fatigue damage (WFD). The
FAA is issuing this AD to address cracks, skin buckles, wrinkles,
and bulges at fuselage longitudinal lap splice areas at S-4, S-14
and S-24. This condition, if not addressed, could result in a large
crack in the fuselage skin, which may result in the inability of a
principal structural element to sustain limit load, which could
result in reduced structural integrity of the airplane and lead to a
decompression event.
(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
Special Attention Requirements Bulletin 737-53-1399 RB, dated May
20, 2022, do all applicable actions identified in, and in accordance
with, the Accomplishment Instructions of Boeing Special Attention
Requirements Bulletin 737-53-1399 RB, dated May 20, 2022.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Special Attention Service
Bulletin 737-53-1399 RB, dated May 20, 2022, which is referred to in
Boeing Special Attention Requirements Bulletin 737-53-1399 RB, dated
May 20, 2022.
(h) Exceptions to Service Information Specifications
(1) Where the Compliance Time columns of the tables in the
``Compliance'' paragraph of Boeing Special Attention Requirements
Bulletin 737-53-1399 RB, dated May 20, 2022, use the phrase ``the
original issue date of Boeing Special Attention Requirements
Bulletin 737-53-1399 RB,'' this AD requires using ``the effective
date of this AD.''
(2) Where Boeing Special Attention Requirements Bulletin 737-53-
1399 RB, dated May 20, 2022, specifies contacting Boeing for repair
instructions or for alternative inspections: This AD requires doing
the repair and doing the alternative inspections and applicable on-
condition actions using a method approved in accordance with the
procedures specified in paragraph (i) of this AD.
(i) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Seattle ACO 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: <a href="/cdn-cgi/l/email-protection#9aa3b7dbd4d7b7c9fffbeeeef6ffb7dbd9d5b7dbd7d5d9b7c8ffebefffe9eee9dafcfbfbb4fdf5ec"><span class="__cf_email__" data-cfemail="98a1b5d9d6d5b5cbfdf9ececf4fdb5d9dbd7b5d9d5d7dbb5cafde9edfdebecebd8fef9f9b6fff7ee">[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, Seattle
ACO 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 Willard
Ashforth, Senior Aerospace Engineer, Airframe Section, FAA, Seattle
ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3520; email: <a href="/cdn-cgi/l/email-protection#debcb7b2b2f0bfadb6b8b1acaab69eb8bfbff0b9b1a8"><span class="__cf_email__" data-cfemail="690b00050547081a010f061b1d01290f0808470e061f">[email protected]</span></a>.
(2) For service information 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; internet <a href="http://myboeingfleet.com">myboeingfleet.com</a>. You may
view this referenced service information 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.
Issued on September 29, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2022-24244 Filed 11-8-22; 8:45 am]
BILLING CODE 4910-13-P
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