Rule2023-14331
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
July 7, 2023
Effective
August 11, 2023
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-8 series airplanes. This AD was prompted by a report of stress corrosion cracking in certain stringers and end stringer splice assemblies. This AD requires repetitive inspections of the stringers and end stringer splice assemblies for any crack, shim, or gap, and 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 88 Issue 129 (Friday, July 7, 2023)</title>
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[Federal Register Volume 88, Number 129 (Friday, July 7, 2023)]
[Rules and Regulations]
[Pages 43253-43256]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-14331]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-0157; Project Identifier AD-2022-01309-T;
Amendment 39-22466; AD 2023-12-08]
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 747-8 series airplanes. This AD was
prompted by a report of stress corrosion cracking in certain stringers
and end stringer splice assemblies. This AD requires repetitive
inspections of the stringers and end stringer splice assemblies for any
crack, shim, or gap, and applicable on-condition actions. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective August 11, 2023.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 11,
2023.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2023-0157; 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 service information identified in this final rule,
contact Boeing Commercial Airplanes, Attention: Contractual & Data
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57,
[[Page 43254]]
Seal Beach, CA 90740-5600; telephone 562-797-1717; website
<a href="http://myboeingfleet.com">myboeingfleet.com</a>.
<bullet> You may view this 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> under Docket No. FAA-2023-0157.
FOR FURTHER INFORMATION CONTACT: Stefanie N. Roesli, Aviation Safety
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone:
206-231-3964; email: <a href="/cdn-cgi/l/email-protection#3c6f48595a5d5255591272126e53594f50557c5a5d5d125b534a"><span class="__cf_email__" data-cfemail="6132150407000f08044f2f4f330e04120d08210700004f060e17">[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 747-8 series airplanes. The NPRM published in the Federal
Register on February 15, 2023 (88 FR 9773). The NPRM was prompted by a
report indicating cracks found on end stringers of two Model 747-8
airplanes at station (STA) 2285, left and right sides, during foreign
object debris (FOD) inspections in preparation for airplane
modification. The cracks were not visually detectable until the
stringer splice assemblies were removed. The root cause was found to be
stress corrosion cracking caused by excessive and sustained internal
tensile stresses that were due to no shim being installed or shimmed
gaps exceeding engineering limits at production. In the NPRM, the FAA
proposed to require repetitive inspections of the stringers and end
stringer splice assemblies for any crack, shim, or gap, and applicable
on-condition actions. The FAA is issuing this AD to prevent cracks in a
stringer or end stringer splice assembly increasing in length and going
undetected. This condition, if not addressed, could result in the
inability of a structural element to sustain limit load and could
adversely affect the structural integrity of the airplane.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from The Boeing Company who supported
the NPRM without change.
The FAA received an additional comment from an individual
commenter. The following presents the comment received on the NPRM and
the FAA's response to the comment.
Request for Root Cause of Stress Corrosion Cracks (SCCs)
The individual commenter requested if Boeing provided heat
treatment specification as a root cause of SCCs and the quality process
for verification of SCC nucleation was within their shelf life. The
individual indicated a larger production deficiency for an airplane
that has been out of production, and stated that this unsafe condition
should not be treated as widespread fatigue damage.
During the root-cause investigation to determine the appropriate
corrective actions, the FAA considered material changes and evaluated
the manufacturing and assembly process. This evaluation would have
included any necessary changes to treatment specifications and quality
inspections. The FAA has not changed this AD.
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.
Clarification of Terminating Action
Boeing Alert Requirements Bulletin 747-53A2909 RB, dated September
21, 2022, contains a terminating action flagnote (b) in Tables 1
through 4 of the Accomplishment Instructions that specifies ``Doing the
detailed and High Frequency Eddy Current (HFEC) inspections and finding
no crack as a result of the inspection is terminating action to
Requirements Bulletin 747-53A2909 RB for that affected end stringer
splice assembly.'' However, the flagnote ``(b)'' is located with
certain conditions in Tables 1 through 4 and appears to be
contradictory in certain locations, e.g., ``Condition 8.2: No crack
found as a result of option 2 inspections'' specifies to do repetitive
inspections; however the option 2 inspections are the detailed and HFEC
inspections, which the flagnote specifies is terminating action. The
FAA has clarified the terminating action in paragraphs (g)(1) through
(4) of this AD to confirm that no action is required for an end
stringer splice assembly on which no cracking is found after the
specified option 2 inspections are done.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 747-53A2909 RB,
dated September 21, 2022. This service information specifies procedures
for repetitive detailed inspections of the stringers and the end
stringer splice assemblies at stringers S-17 to S-25 from STA 2285 to
STA 2300 main entry door #5 cutout aft edge frame for any crack, any
shim between a stringer and bear strap, and any gap within the
fastener-joint-to-bear-strap joint, and applicable on-condition
actions. On-condition actions include detailed inspections of the
stringers and end stringers splice assemblies located between STA 2285
and STA 2300 from stringers S-17L to S-25L/S-17R to S-25R, open hole
high HFEC inspection of the fastener holes of the skin common to the
end stringer splice fitting for cracks, and repair of cracked stringer/
end stringer splice fittings.
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 2 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost on U.S.
Action Labor cost Parts cost Cost per product operators
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Detailed Inspection (S-17L to S- 4 work-hours x $85 per $0 $340 per $680 per
25L) and (S-17R to S-25R). hour = $340 per inspection cycle. inspection
inspection cycle. cycle.
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[[Page 43255]]
The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of the
proposed inspection. The agency has no way of determining which, if
any, of the affected airplanes 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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Detailed Inspection and Open Hole HFEC 54 work-hours x $85 per hour = $0 $4,590
Inspection per side. $4,590.
Repair of cracked stringer/end stringer 13 work-hours x $85 per hour = 600 1,705
splice fitting. $1,105.
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The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this AD may be covered under warranty, thereby reducing the cost impact
on affected operators.
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:
2023-12-08 The Boeing Company: Amendment 39-22466; Docket No. FAA-
2023-0157; Project Identifier AD-2022-01309-T.
(a) Effective Date
This airworthiness directive (AD) is effective August 11, 2023.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 747-8 series
airplanes, certificated in any category, as identified in Boeing
Alert Requirements Bulletin 747-53A2909 RB, dated September 21,
2022.
(d) Subject
Air Transport Association (ATA) of America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by a report of stress corrosion cracking in
the stringers and end stringer splice assemblies located between
station (STA) 2285 and STA 2300 from stringers S-17 to S-25 on the
left and right sides of the airplane caused by excessive and
sustained internal tensile stresses that were due to no shim being
installed or shimmed gaps exceeding engineering limits at
production. A crack in a stringer or end stringer splice assembly
could grow in length and go undetected. The unsafe condition, if not
addressed, could result in the inability of a structural element to
sustain limit load and 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
Except as specified by paragraph (h) of this AD: At the
applicable times specified in the ``Compliance'' paragraph of Boeing
Alert Requirements Bulletin 747-53A2909 RB, dated September 21,
2022, do all applicable actions identified in, and in accordance
with, the Accomplishment Instructions of Boeing Alert Requirements
Bulletin 747-53A2909 RB, dated September 21, 2022. For this AD,
terminating action for certain end stringer springer splice
assemblies are specified in paragraphs (g)(1) through (4) of this
AD.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
747-53A2909, dated September 21, 2022, which is referred to in
Boeing Alert Requirements Bulletin 747-53A2909 RB, dated September
21, 2022.
(1) For any end stringer splice assembly on which no cracking is
found after accomplishing CONDITION 3 (OPTION 2) (ACTION 1) and
CONDITION 3 (OPTION 2) (ACTION 2) inspections specified in Table 1
of the Accomplishment Instruction of Boeing Alert Requirements
Bulletin 747-53A2909 RB, dated September 21, 2022, no further action
is required by this AD for that end stringer splice assembly.
(2) For any end stringer splice assembly on which no cracking is
found after accomplishing CONDITION 6 (OPTION 2) (ACTION 1) and
CONDITION 6 (OPTION 2) (ACTION 2) inspections specified in Table 2
of the Accomplishment Instruction of Boeing Alert Requirements
Bulletin 747-53A2909 RB, dated September 21, 2022, no further action
is required by this AD for that end stringer splice assembly.
(3) For any end stringer splice assembly on which no cracking is
found after accomplishing CONDITION 8 (OPTION 2) (ACTION 1) and
CONDITION 8 (OPTION 2) (ACTION 2) inspections specified in Table 3
of the Accomplishment Instruction of Boeing Alert Requirements
Bulletin 747-53A2909 RB, dated September 21, 2022, no further action
is required by this AD for that end stringer splice assembly.
(4) For any end stringer splice assembly on which no cracking is
found after accomplishing CONDITION 10 (OPTION 2)
[[Page 43256]]
(ACTION 1) and CONDITION 10 (OPTION 2) (ACTION 2) inspections
specified in Table 4 of the Accomplishment Instruction of Boeing
Alert Requirements Bulletin 747-53A2909 RB, dated September 21,
2022, no further action is required by this AD for that end stringer
splice assembly.
(h) Exceptions to Service Information Specifications
(1) Where the Compliance Time column and certain notes of the
tables in the ``Compliance'' paragraph of Boeing Alert Requirements
Bulletin 747-53A2909 RB, dated September 21, 2022, use the phrase
``the original issue date of Requirements Bulletin 747-53A2909 RB,''
this AD requires using ``the effective date of this AD.''
(2) Where Boeing Alert Requirements Bulletin 747-53A2909 RB,
dated September 21, 2022, specifies contacting Boeing for repair
instructions: This AD requires doing the repair 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, 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: <a href="/cdn-cgi/l/email-protection#221b0f636c6f0f71474356564e470f63616d0f636f6d610f7047535747515651624443430c454d54"><span class="__cf_email__" data-cfemail="665f4b27282b4b35030712120a034b2725294b272b29254b34031713031512152600070748010910">[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,
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
For more information about this AD, contact Stefanie N. Roesli,
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines,
WA 98198; phone: 206-231-3964; email: <a href="/cdn-cgi/l/email-protection#386b4c5d5e5956515d1676166a575d4b5451785e5959165f574e"><span class="__cf_email__" data-cfemail="0556716063646b6c602b4b2b576a6076696c456364642b626a73">[email protected]</span></a>.
(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 747-53A2909 RB, dated
September 21, 2022.
(ii) [Reserved]
(3) 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; website <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
(4) You may view this 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.
(5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, <a href="/cdn-cgi/l/email-protection#7214005c1b1c01021711061b1d1c321c1300135c151d04"><span class="__cf_email__" data-cfemail="eb8d99c58285989b8e889f828485ab858a998ac58c849d">[email protected]</span></a>, or go to: <a href="http://www.archives.gov/federal-register/cfr/ibr-locations.html">www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued on June 13, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2023-14331 Filed 7-6-23; 8:45 am]
BILLING CODE 4910-13-P
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