Airworthiness Directives; The Boeing Company Airplanes

[Federal Register Volume 88, Number 129 (Friday, July 7, 2023)]
[Rules and Regulations]
[Pages 43251-43253]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-14332]



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Rules and Regulations
                                                Federal Register
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Federal Register / Vol. 88, No. 129 / Friday, July 7, 2023 / Rules 
and Regulations

[[Page 43251]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0816; Project Identifier AD-2022-00355-T; 
Amendment 39-22477; AD 2023-12-18]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 747-8 and -8F series airplanes. This 
AD was prompted by reports of cracking in stringers and splice fittings 
located at stringer splices at multiple body stations. This AD requires 
an inspection of each free flange of the stringers at the stringer 
splice for the presence of radius fillers at fastener locations, an 
inspection for cracking of the stringers and stringer splice fittings 
at certain stringer splice locations, 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 regulations.gov under 
Docket No. FAA-2022-0816; 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, Seal Beach, CA 
90740-5600; telephone 562-797-1717; website myboeingfleet.com.
    <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 
regulations.gov under Docket No. FAA-2022-0816.

FOR FURTHER INFORMATION CONTACT: Stefanie Roesli, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3964; 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 747-8 and -8F series airplanes. The NPRM published in the 
Federal Register on September 8, 2022 (87 FR 54917). The NPRM was 
prompted by reports of cracking in stringers and splice fittings 
located at stringer splices at multiple body stations. In the NPRM, the 
FAA proposed to require an inspection of each free flange of the 
stringers at the stringer splice for the presence of radius fillers at 
fastener locations, an inspection for cracking of the stringers and 
stringer splice fittings at certain stringer splice locations, and 
applicable on-condition actions. The FAA is issuing this AD to address 
such cracking, which could result in the inability of a structural 
element to sustain limit load and could affect structural integrity of 
the airplane.
    The FAA issued a supplemental notice of proposed rulemaking (SNPRM) 
to amend 14 CFR part 39 by adding an AD that would apply to certain The 
Boeing Company Model 747-8 and -8F series airplanes. The SNPRM 
published in the Federal Register on April 6, 2023 (88 FR 20438). The 
SNPRM was prompted by additional reports of cracked stringers, with a 
total of 595 cracked stringers reported since the issue was initially 
evaluated in 2020. In May 2022, cracked stringers were found in a 
location where the previously repaired stringer location had 
accumulated zero flight cycles (FC) since the repair. Due to the large 
number of crack findings and the unknown long-term reliability of 
repairs, combined with airplanes with low utilization rates that may 
not reach the initial compliance time in the NPRM (before 12,000 total 
flight cycles or within 38 months after the effective date of this AD, 
whichever occurs later) for an extended period of time, the FAA 
determined that it is necessary to add a calendar-based compliance time 
for certain actions. The FAA therefore determined that a more 
appropriate compliance time for the initial inspections is before 
12,000 total FC, or within 8 years after the date of issuance of the 
original certificate of airworthiness or the original export 
certificate of airworthiness, whichever occurs first; or within 38 
months after the effective date of this AD; whichever occurs later. The 
FAA also determined that a calendar-based compliance time should be 
added to the repeat inspection intervals too. The FAA is issuing this 
AD to address such cracking, which could result in the inability of a 
structural element to sustain limit load and could affect structural 
integrity of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from The Boeing Company who supported 
the SNPRM without change.

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 SNPRM. None of the changes will 
increase the economic burden on any operator.

[[Page 43252]]

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 747-53A2907 RB, 
dated March 3, 2022. This service information specifies procedures for 
an inspection of each free flange of the stringers at the stringer 
splice for the presence of radius fillers at fastener locations, an 
inspection for cracking of the stringers and stringer splice fittings 
at certain stringer splice locations, and applicable on-condition 
actions. On-condition actions include follow-on detailed inspections 
for cracking or the presence of radius fillers, removal or installation 
of radius fillers, and repair. 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 40 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                  Cost on U.S.
             Action                    Labor cost            Parts cost     Cost per  product      operators
----------------------------------------------------------------------------------------------------------------
Inspection for radius filler...  Up to 124 work-hours x  None.............  Up to $10,540....  Up to $421,600.
                                  $85 per hour =
                                  $10,540.
Inspection for cracking........  Up to 244 work-hours x  None.............  Up to $20,740....  Up to $829,600.
                                  $85 per hour =
                                  $20,740.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of the 
inspection. The agency has no way of determining the number of aircraft 
that might need these actions:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
               Action                         Labor cost                Parts cost           Cost per product
----------------------------------------------------------------------------------------------------------------
Inspection for cracking or for       1 work-hour x $85 per hour   None..................  $85 per inspection
 radius fillers.                      = $85.                                               location.
Removing radius fillers and          7 work-hours x $85 per hour  None..................  $595 per location.
 inspection.                          = $595.
Replacement of cracked splice        300 work-hours x $85 per     $809..................  $26,309 per
 channel.                             hour = $25,500.                                      replacement.
----------------------------------------------------------------------------------------------------------------

    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:

2023-12-18 The Boeing Company: Amendment 39-22477; Docket No. FAA-
2022-0816; Project Identifier AD-2022-00355-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 and -8F series 
airplanes, certificated in any category, as identified in Boeing 
Alert Requirements Bulletin 747-53A2907 RB, dated March 3, 2022.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

[[Page 43253]]

(e) Unsafe Condition

    This AD was prompted by reports of cracking in stringers and 
splice fittings located at stringer splices at multiple body 
stations. The FAA is issuing this AD to address such cracking, which 
could result in the inability of a structural element to sustain 
limit load and could affect 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 747-53A2907 RB, dated March 3, 2022, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
747-53A2907 RB, dated March 3, 2022.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
747-53A2907, dated March 3, 2022, which is referred to in Boeing 
Alert Requirements Bulletin 747-53A2907 RB, dated March 3, 2022.

(h) Exceptions to Service Information Specifications

    (1) Where the Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 747-
53A2907 RB, dated March 3, 2022, use the phrase ``the original issue 
date of Requirements Bulletin 747-53A2907 RB,'' this AD requires 
using ``the effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 747-53A2907 RB, 
dated March 3, 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.
    (3) Where the Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 747-
53A2907 RB, dated March 3, 2022, use the phrase ``Before 12,000 
total flights cycles,'' this AD requires using ``Before 12,000 total 
flight cycles, or within 8 years after the date of issuance of the 
original certificate of airworthiness or the original export 
certificate of airworthiness, whichever occurs first.''
    (4) Where the Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 747-
53A2907 RB, dated March 3, 2022, uses the phrase ``Within 9,600 
flight cycles after the last detailed inspection,'' this AD requires 
using ``Within 9,600 flight cycles or 8 years after the last 
detailed inspection, whichever occurs first.''
    (5) Where the Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 747-
53A2907 RB, dated March 3, 2022, uses the phrase ``Within 4,600 
flight cycles after the last detailed inspection,'' this AD requires 
using ``Within 4,600 flight cycles or 8 years after the last 
detailed inspection, whichever occurs first.''

(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, 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 Stefanie Roesli, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3964; email: [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (k)(3) and (4) 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 747-53A2907 RB, dated 
March 3, 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 myboeingfleet.com.
    (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, [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on June 13, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-14332 Filed 7-6-23; 8:45 am]
BILLING CODE 4910-13-P

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