[Federal Register Volume 89, Number 65 (Wednesday, April 3, 2024)]
[Rules and Regulations]
[Pages 22925-22928]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-06995]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1046; Project Identifier AD-2023-00253-T; 
Amendment 39-22700; AD 2024-05-09]
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 757-200, -200CB, and -300 series 
airplanes. This AD was prompted by a report of a crack at fuselage 
station (STA) 1640 frame web common to the lower hinge intercostal tee 
clip center hole of the upper fastener row. This AD requires a 
maintenance records check for existing repairs at STA 1640, repetitive 
ultrasonic (UT) inspections for cracking of the frame web, and 
applicable on-condition actions. The FAA is issuing this AD to address 
the unsafe condition on these products.

DATES: This AD is effective May 8, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 8, 2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-1046; 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 material identified in this final rule, 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 that is incorporated by 
reference 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-2023-1046.

FOR FURTHER INFORMATION CONTACT: Wayne Ha, Aviation Safety Engineer, 
Continued Operational Safety Branch, FAA, 2200 South 216th Street, Des 
Moines, WA 98198; phone: 562-627-5238; 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 757-200, -200CB, and -300 series airplanes. The NPRM 
published in the Federal Register on June 1, 2023 (88 FR 35783). The 
NPRM was prompted by a report of a crack at fuselage STA 1640 frame web 
common to the lower hinge intercostal tee clip center hole of the upper 
fastener row. In the NPRM, the FAA proposed to require a maintenance 
records check for existing repairs at STA 1640, repetitive UT 
inspections for cracking of the frame web, and applicable on-condition 
actions. The FAA is issuing this AD to address possible undetected 
cracking in the STA 1640 frame web common to the lower hinge 
intercostal tee clip center hole of the upper fastener row. Such 
cracking, if not addressed, could result in the inability of a 
principal structural element to sustain limit loads which could 
adversely affect the structural integrity of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from Air Line Pilots Association, 
International, who supported the NPRM without change.
    The FAA received additional comments from seven commenters, 
including Aviation Partners Boeing (APB), Boeing, Delta Air Lines 
(DAL), European Air Transport GmbH (DHL), FedEx Express, United 
Airlines (UAL), and VT Mobile Aerospace Engineering, Inc. (VT MAE). The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request To Correct the Location of the Unsafe Condition

    Boeing requested that the location of the cracking be corrected 
from ``inboard and center holes'' to ``center hole'' of the upper 
fastener row in the Summary and Background of the NPRM, and paragraph 
(e) of the proposed AD. Boeing said that cracking was found only in the 
center hole.
    The FAA agrees. The correction has been made in the specified 
sections of this AD.

Request To Change Inspection Requirement for Certain Converted 
Airplanes

    VT MAE proposed that no additional inspection be required other 
than the inspection specified in VT MAE 15-Pallet Maintenance Planning 
Data (MPD) Supplement 757SF-MPD-01 for airplanes converted per VT MAE 
Supplemental Type Certificate (STC) ST04242AT. VT MAE asserted that 
Boeing has performed analysis of the modified airplanes, including the 
new STA 1640 frame, which is inspected as part of the VT MAE MPD 
Supplement 757SF-MPD-01.
    The FAA disagrees with the commenter's request because sufficient

[[Page 22926]]

data was not submitted to substantiate that the inspections specified 
in VT MAE MPD Supplement 757SF-MPD-01 would provide an acceptable level 
of safety. Under the provisions of paragraph (i) of this AD, however, 
the FAA will consider requests for approval of alternative actions and 
compliance times if sufficient data are submitted to substantiate that 
the change would provide an acceptable level of safety. The FAA has not 
changed this AD in this regard.

Request To Clarify a Certain Exception

    DAL requested that paragraph (h)(3) of the proposed AD be amended 
or revised to clarify whether aircraft configured with STC ST01518SE 
but without winglets require the specified reduction in applicable 
compliance times and repeat intervals. DAL stated that this approved 
configuration was not clearly addressed in the proposed AD.
    The FAA agrees to clarify. Because a longer compliance time for the 
identified configuration (STC ST01518SE without winglets) has not been 
evaluated, all configurations with the STC ST01518SE modification must 
be included in the requirement. The FAA has revised paragraph (h)(3) of 
this AD to specify that airplanes modified in accordance APB STC 
ST01518SE, with or without blended or scimitar blended winglets 
installed, have the reduced compliance time. However, as specified in 
paragraph (i) of this AD, the FAA will consider requests for approval 
of alternative actions and compliance times if sufficient data are 
submitted to substantiate that the change would provide an acceptable 
level of safety.

Request To Clarify What Prompted the NPRM

    Boeing requested that the Background section of the NPRM be revised 
to clarify the sequence of events and the associated service documents 
that led to detection of the cracking that prompted the NPRM. Boeing 
asserted that the NPRM indicated that the crack was found as a result 
of inspections required by AD 2020-20-10, Amendment 39-21266 (85 FR 
63002, October 6, 2020) (AD 2020-20-10), but the crack was actually 
found as a result of inspections required by AD 2018-06-07, Amendment 
39-19227 (83 FR 13398, March 29, 2018) (AD 2018-06-07).
    The FAA agrees that the AD number reference in the Background 
section of the NPRM described by Boeing should have been AD 2018-06-07 
(which was superseded by AD 2020-20-10). However, since that portion of 
the Background section does not reappear in the final rule, no change 
to the final rule is necessary.

Request To Extend Compliance Time

    APB, DAL, and DHL proposed that APB Service Bulletin AP757-53-005 
be incorporated into the final rule. APB, DAL, DHL, and UAL suggested 
that paragraph (h)(3) of the proposed AD be revised to extend the 
required time for compliance. APB explained that APB Service Bulletin 
AP757-53-005 is currently in approval review by an independent DER 
(Designated Engineering Representative) for submittal to the FAA, and 
this service information proposes less restrictive compliance times 
than specified by paragraphs (g) and (h)(3) of the proposed AD. DHL 
added that halving the compliance time for the initial inspection is 
more burdensome than halving the time for repetitive inspections, which 
can still be accomplished during base maintenance events. DAL and UAL 
added that the reduced initial inspection time would mean that the 
inspection could not occur during a regularly scheduled check, 
resulting in extended unscheduled ground time and increased costs for 
operators.
    The FAA does not agree. Waiting for the review and approval of APB 
Service Bulletin AP757-53-005 would delay the rulemaking process. The 
urgency of the unsafe condition warrants issuing this AD as proposed 
because it adequately addresses the unsafe condition. Until APB 
completes its evaluation of airplanes with APB STC ST01518SE installed 
to determine an appropriate compliance time for the inspection, the 
conservative factor of 2 will apply to these airplanes. Under the 
provisions of paragraph (i) of this AD, however, the FAA will consider 
requests for approval of alternative compliance times if sufficient 
data are submitted to substantiate that the change would provide an 
acceptable level of safety. The FAA has not changed this AD in this 
regard.

Request for Clarification on Credit for Certain Airplanes

    UAL requested clarification on the NPRM as it does not give 
operators credit for airplanes on which the required inspection in 
Boeing Alert Requirements Bulletin 757-53A0121 RB, dated September 28, 
2022, was already accomplished prior to release of the pending AD. UAL 
said they intend to start inspection as soon as possible, and not 
having any allowance for credit prior to AD release may drive some of 
UAL's Model 757 fleet into another round of the required inspection 
sooner than the required repetitive inspection time limit.
    The FAA provides the following clarification. Paragraph (f) of this 
AD states that operators must comply with the requirements of the AD 
unless those actions have already been done, which negates the need to 
add the requested credit. Any repetitive actions must be done within 
the compliance times required by this AD. This AD has not been changed 
regarding this request.

Request To Exclude Certain Airplanes From AD Requirements

    VT MAE requested that no inspection be required for aircraft 
converted per ST03952AT that have a long inner chord strap at the STA 
1640 fuselage frame. VT MAE and FedEx Express requested that no 
inspection be required for aircraft converted per VT MAE STC ST03562AT 
that have a long inner chord strap at the STA 1640 fuselage frame. The 
commenters asserted that the modified STA 1640 frame is identical to 
that of Boeing 757-200 special freighter airplanes, which are not 
included in Boeing Alert Requirements Bulletin 757-53A0121 RB, dated 
September 28, 2022. The commenters claimed that Boeing and the FAA 
stated that these special freighter-configured airplanes were not 
subject to cracking at the lower hinge intercostal tee clip. The 
commenters stated that the stresses in the inner chord are higher, and 
AD 2020-20-10 and Boeing Alert Service Bulletin 757-53A0108, Revision 
1, dated July 17, 2019, would be able to detect the web cracks sooner.
    The FAA agrees with the proposed change. For aircraft converted per 
VT MAE STC ST03562AT and ST03952AT that have a long inner chord strap 
at the STA 1640 fuselage frame, the modified STA 1640 frame is 
identical to that of Boeing 757-200 special freighter airplanes. 
Paragraph (h)(4) of this AD has been added to provide an exception 
stating that the actions of paragraph (g) of this AD are not required 
for Group 1 airplanes that have been converted from passenger to 
freighter configuration using VT MAE STC ST03562AT or ST03952AT that 
have a long inner chord strap at the STA 1640 fuselage frame.

Request for Alternative Required Actions for Certain Airplanes

    VT MAE and FedEx Express requested the use of Group 4 inspections/
methods/compliance times, given in Boeing Alert Requirements Bulletin 
757-53A0121 RB, dated September 28, 2022, for the airplane having 
registration number N935FD, which was converted per VT MAE STC

[[Page 22927]]

ST03562AT. The commenters noted that this airplane has a short inner 
chord strap at the STA 1640 fuselage frame, and that the modified STA 
1640 frame is identical to the STA 1640 frame found on Boeing 757-200 
special freighter airplanes, which are identified as Group 4 in Boeing 
Alert Requirements Bulletin 757-53A0121 RB, dated September 28, 2022.
    The FAA agrees that the modified STA 1640 frame is identical to the 
STA 1640 frame found on Boeing 757-200 special freighter airplanes, 
identified as Group 4 in Boeing Alert Requirements Bulletin 757-53A0121 
RB, dated September 28, 2022. The FAA has added paragraph (h)(5) of 
this AD to specify that airplanes modified in this manner should 
accomplish the actions for Group 4 airplanes at the applicable times 
for Group 4 airplanes, as specified in Boeing Alert Requirements 
Bulletin 757-53A0121 RB, dated September 28, 2022.

Limited ODA Approvals

    APB stated that Boeing does not have a delegation to approve 
repairs in areas affected by the scimitar blended winglet configuration 
of STC ST01518SE. APB also commented that approval by The Boeing 
Company Organization Designation Authorization (ODA), as specified in 
paragraph (i)(3) of the proposed AD, may not be given for an 
alternative method of compliance (AMOC) for repairs in those areas, but 
such approval must be obtained as specified in paragraph (i)(1) of this 
AD.
    The FAA acknowledges and concurs with APB's assertions. However, no 
change to the AD is necessary. Paragraph (h)(2) of this AD states that 
AMOC approval be obtained using a method approved in accordance with 
the procedures specified in ``paragraph (i)'' of this AD, and does not 
limit approvals to the provisions of paragraph (i)(1) or (3) of this 
AD. Therefore, AMOC approval in accordance with paragraph (i)(1) or (3) 
of this AD would be provided based on whether the actions needing an 
AMOC apply to the APB design or the Boeing design.

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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 757-53A0121 RB, 
dated September 28, 2022. This service information specifies procedures 
for a maintenance records check of the left- and right-side STA 1640 
frame web between S-9 and S-20 for existing repairs; repetitive UT 
inspections of the frame web for any cracks; and applicable on-
condition actions. On-condition actions include 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 section.

Costs of Compliance

    The FAA estimates that this AD affects 309 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
----------------------------------------------------------------------------------------------------------------
Maintenance records check........  1 work-hour x $85                $0  $85................  $26,265.
                                    per hour = $85.
UT inspection....................  39 work-hours x $85              $0  $3,315 per           $1,024,335 per
                                    per hour = $3,315                    inspection cycle.    inspection cycle.
                                    per inspection
                                    cycle.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs 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:
    (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:

2024-05-09 The Boeing Company: Amendment 39-22700; Docket No.

[[Page 22928]]

FAA-2023-1046; Project Identifier AD-2023-00253-T.

(a) Effective Date

    This airworthiness directive (AD) is effective May 8, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 757-200, -200CB, and 
-300 series airplanes, certificated in any category, as identified 
in Boeing Alert Requirements Bulletin 757-53A0121 RB, dated 
September 28, 2022.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report of a crack at fuselage station 
(STA) 1640 frame web common to the lower hinge intercostal tee clip 
center hole of the upper fastener row. This condition, if not 
addressed, could result in the inability of a principal structural 
element to sustain limit loads, 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

    Except as specified by paragraph (h) of this AD: At the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 757-53A0121 RB, dated September 28, 
2022, do all applicable actions identified in, and in accordance 
with, the Accomplishment Instructions of Boeing Alert Requirements 
Bulletin 757-53A0121 RB, dated September 28, 2022.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
757-53A0121, dated September 28, 2022, which is referred to in 
Boeing Alert Requirements Bulletin 757-53A0121 RB, dated September 
28, 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 757-
53A0121 RB, dated September 28, 2022, use the phrase ``the original 
issue date of Requirements Bulletin 757-53A0121 RB,'' this AD 
requires replacing those words with ``the effective date of this 
AD.''
    (2) Where Boeing Alert Requirements Bulletin 757-53A0121 RB, 
dated September 28, 2022, 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 using a method approved in accordance with the 
procedures specified in paragraph (i) of this AD.
    (3) For airplanes modified in accordance with Aviation Partners 
Boeing (APB) Supplemental Type Certificate (STC) ST01518SE, with or 
without blended or scimitar blended winglets installed: This AD 
requires dividing the applicable compliance times and repeat 
intervals specified in the ``Compliance'' paragraph of Boeing Alert 
Requirements Bulletin 757-53A0121 RB, dated September 28, 2022, by a 
factor of two.
    (4) For Group 1 airplanes identified in Boeing Alert 
Requirements Bulletin 757-53A0121 RB, dated September 28, 2022, that 
have been converted from passenger to freighter configuration using 
VT MAE STC ST03562AT or ST03952AT and that have a long inner chord 
strap part number 146N8711-65 at the STA 1640 fuselage frame: The 
actions specified in paragraph (g) of this AD are not required.
    (5) For Group 3 airplanes identified in Boeing Alert 
Requirements Bulletin 757-53A0121 RB, dated September 28, 2022, that 
have been converted from passenger to freighter configuration using 
VT MAE STC ST03562AT: Do all applicable actions for Group 4, as 
identified in, and in accordance with, Boeing Alert Requirements 
Bulletin 757-53A0121 RB, dated September 28, 2022, at the applicable 
times for Group 4 as specified in the ``Compliance'' paragraph of 
Boeing Alert Requirements Bulletin 757-53A0121 RB, dated September 
28, 2022.

(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)(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, 
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 Wayne Ha, 
Aviation Safety Engineer, Continued Operational Safety Branch, FAA, 
2200 South 216th Street, Des Moines, WA 98198; phone: 562-627-5238; 
email: [email protected].
    (2) Service information 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 (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 757-53A0121 RB, dated 
September 28, 2022.
    (ii) [Reserved]
    (3) For 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 that is incorporated by reference 
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 protected].

    Issued on March 4, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-06995 Filed 4-2-24; 8:45 am]
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