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Published 2021-08-31 · Federal Register document 2021-18705

Airworthiness Directives; The Boeing Company Airplanes

Publication summary

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, - 200F, -300, -400, -400D, -400F, 747SR, and 747SP airplanes. This AD was prompted by reports of cracks found in the front spar shear tie and at the intercostal lug fitting at certain locations. This AD requires repetitive detailed and surface high frequency eddy current (HFEC) inspections of the front spar shear tie and intercostal lug fitting at certain locations for any cracking, and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.

Why this record is shown

Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:24:08.106391+00:00. The title, summary and date are source facts.

Source revision
federal_register_ad_metadata_2021-9c919420683447c6
Source row
results[310]
Raw source SHA-256
9c919420683447c683ad0c877cb886e341c11862be32b47c536a001b1d76dcb5

Final-rule publication

Recorded publication clauses

AD identifier printed in this edition
2021-17-06
Effective date printed in this edition
2021-10-05
Read 11 complete recorded clauses
Effective Date
(a) Effective Date

    This airworthiness directive (AD) is effective October 5, 2021.

Exact source excerpt. Text positions 10322–10411, end exclusive, in the original decoded publication. SHA-256: e98fda833eb82745af1318b144837fbfc0d8f4e034ad01438d24e2927f86fd25

Affected ADs
(b) Affected ADs

    None.

Exact source excerpt. Text positions 10411–10440, end exclusive, in the original decoded publication. SHA-256: 871a4afc60ceeae06e8010585055188633d616078500c45937092bfe892239c0

Applicability wording · Applicability
(c) Applicability

    This AD applies to all The Boeing Company Model 747-100, -100B, 
-100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, 747SR, and 
747SP airplanes, certificated in any category.

Exact source excerpt. Text positions 10440–10646, end exclusive, in the original decoded publication. SHA-256: a591169fdd5d5e259d028447cf25111bccf21ef88f3094b0f3018941d9595933

Subject
(d) Subject

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

Exact source excerpt. Text positions 10646–10726, end exclusive, in the original decoded publication. SHA-256: 297e69b8a6e159f28612e8bd82a91daa2fd8fd1d9d38af67161f67738908fa6c

Unsafe Condition
(e) Unsafe Condition

    This AD was prompted by reports of cracks in the station (STA) 
1000 front spar shear tie at the left and right side buttock line 
(BL) 11.33, BL 33.99, BL 57.50, and BL 75.92, and in the intercostal 
lug fitting at the left and right side BL 11.33. The FAA is issuing 
this AD to address any cracking in these areas that could result in 
the loss of limit load capability in a principal structural element, 
the potential inability to restrain the cargo for certain cargo 
configurations, and the potential for a center fuel tank rupture for 
certain cargo configurations under limit load conditions, which 
could adversely affect the structural integrity of the airplane.

Exact source excerpt. Text positions 10726–11427, end exclusive, in the original decoded publication. SHA-256: 44ecf67b7c85ea14c89b2450ddb0df9c2d657e8f20ac1d0a66dd2d802ce6a0b3

Compliance
(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

Exact source excerpt. Text positions 11427–11529, end exclusive, in the original decoded publication. SHA-256: 00fbfa31932483f627d0ce0a11cbd2e35e15d9231842b91ac85623ce533912d3

Required Actions
(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 747-53A2904 RB, dated December 16, 2020, 
do all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
747-53A2904 RB, dated December 16, 2020.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
747-53A2904, dated December 16, 2020, which is referred to in Boeing 
Alert Requirements Bulletin 747-53A2904 RB, dated December 16, 2020.

Exact source excerpt. Text positions 11529–12206, end exclusive, in the original decoded publication. SHA-256: 8dc6b7b371d3a27b9bb2b9b87626933998fb9ce7f9a9d452e712d0bd1fa5cba7

Exceptions to Service Information Specifications
(h) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Requirements Bulletin 747-53A2904 RB, 
dated December 16, 2020, uses the phrase ``the original issue date 
of Requirements Bulletin 747-53A2904 RB,'' this AD requires using 
``the effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 747-53A2904 RB, 
dated December 16, 2020, 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.

[[Page 48485]]

Exact source excerpt. Text positions 12206–12791, end exclusive, in the original decoded publication. SHA-256: 41299cd37b9dc37e45bae3fb91e96425ddb122ddabbd156c10887ef2f81ab0df

Alternative Methods of Compliance (AMOCs)
(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 Related Information. 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, 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.

Exact source excerpt. Text positions 12791–14013, end exclusive, in the original decoded publication. SHA-256: 3dd0a5d02c3800cdd23a57b2d083e3c33fca479fb024fd831e687fa11b0469f5

Related Information
(j) Related Information

    (1) For more information about this AD, contact Stefanie Roesli, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 
South 216th St., Des Moines, WA 98198; phone and fax: 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.

Exact source excerpt. Text positions 14013–14444, end exclusive, in the original decoded publication. SHA-256: 7ab1c02193464581b8118c91fcbf7f8bc83757ae5a131792bc61fc35ca824058

Material Incorporated by Reference
(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 747-53A2904 RB, dated 
December 16, 2020.
    (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; internet https://www.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: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

Exact source excerpt. Text positions 14444–15723, end exclusive, in the original decoded publication. SHA-256: fbf9555b02fac1b58242af33e3d458661947de704823229ffb735b88cd454024

No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.

Find all recorded historical references to AD 2021-17-06 · 0 printed reference observations in this pinned collection.

These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.

Why these observations are shown

They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.

Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: 06cc5740f024ae938101328278f4a349fe482f6f5e8f1472fad4750e469d1d98. Source manifest: f643445b18c67859a114cf71be84f832dafd5be8a13e8e7d97e3566b7b4a73c5.

Official source · 2021-08-31

Publication text

This is the complete recorded text of this dated publication.

Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.

Read the complete official publication text
[Federal Register Volume 86, Number 166 (Tuesday, August 31, 2021)]
[Rules and Regulations]
[Pages 48483-48485]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-18705]



========================================================================
Rules and Regulations
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains regulatory documents 
having general applicability and legal effect, most of which are keyed 
to and codified in the Code of Federal Regulations, which is published 
under 50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by the Superintendent of Documents. 

========================================================================


Federal Register / Vol. 86, No. 166 / Tuesday, August 31, 2021 / 
Rules and Regulations

[[Page 48483]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0376; Project Identifier AD-2021-00062-T; 
Amendment 39-21689; AD 2021-17-06]
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 all 
The Boeing Company Model 747-100, -100B, -100B SUD, -200B, -200C, -
200F, -300, -400, -400D, -400F, 747SR, and 747SP airplanes. This AD was 
prompted by reports of cracks found in the front spar shear tie and at 
the intercostal lug fitting at certain locations. This AD requires 
repetitive detailed and surface high frequency eddy current (HFEC) 
inspections of the front spar shear tie and intercostal lug fitting at 
certain locations for any cracking, and applicable on-condition 
actions. The FAA is issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective October 5, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 5, 
2021.

ADDRESSES: 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; internet https://www.myboeingfleet.com. 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 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2021-0376.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0376; 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.

FOR FURTHER INFORMATION CONTACT: Stefanie Roesli, Aerospace Engineer, 
Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 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 all The Boeing Company 
Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -
400D, -400F, 747SR, and 747SP airplanes. The NPRM published in the 
Federal Register on June 7, 2021 (86 FR 30216). The NPRM was prompted 
by reports of cracks found in the front spar shear tie and at the 
intercostal lug fitting at certain locations. In the NPRM, the FAA 
proposed to require repetitive detailed and surface HFEC inspections of 
the front spar shear tie and intercostal lug fitting at certain 
locations for any cracking, and applicable on-condition actions. The 
FAA is issuing this AD to address any cracking in these areas that 
could result in the loss of limit load capability in a principal 
structural element, the potential inability to restrain the cargo for 
certain cargo configurations, and the potential for a center fuel tank 
rupture for certain cargo configurations under limit load conditions, 
which could adversely affect the structural integrity of the airplane.

Discussion of Final Airworthiness Directive

Comments

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

Conclusion

    The FAA reviewed the relevant data, considered the comment 
received, and determined that air safety requires adopting this AD as 
proposed. 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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 747-53A2904 RB, 
dated December 16, 2020. This service information specifies procedures 
for repetitive detailed and surface HFEC inspections of the station 
1000 front spar shear tie at the left and right side buttock line (BL) 
11.33, BL 33.99, BL 57.50, and BL 75.92, and of the intercostal lug 
fitting at the left and right side BL 11.33, for any cracking, and 
applicable on-condition actions. On-condition actions include repair, 
installing a new front spar shear tie, and installing a new intercostal 
lug fitting. 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 will affect 117 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

[[Page 48484]]



                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
           Action                  Labor cost         Parts cost       Cost per product          operators
----------------------------------------------------------------------------------------------------------------
Inspections................  Up to 314 work-hours               $0  Up to $26,690........  Up to $3,122,730.
                              x $85 per hour = Up
                              to $26,690.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
installations and repairs 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 installations and repairs:

                           On-Condition Costs
------------------------------------------------------------------------
                                                             Cost per
        Action            Labor cost       Parts cost        product
------------------------------------------------------------------------
Installations........  Up to 368 work-  Up to $38,446    Up to $69,726.
                        hour x $85 per   (for shear
                        hour = Up to     ties and
                        $31,280.         intercostal
                                         lug fittings).
------------------------------------------------------------------------

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

2021-17-06 The Boeing Company: Amendment 39-21689; Docket No. FAA-
2021-0376; Project Identifier AD-2021-00062-T.

(a) Effective Date

    This airworthiness directive (AD) is effective October 5, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all The Boeing Company Model 747-100, -100B, 
-100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, 747SR, and 
747SP airplanes, certificated in any category.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of cracks in the station (STA) 
1000 front spar shear tie at the left and right side buttock line 
(BL) 11.33, BL 33.99, BL 57.50, and BL 75.92, and in the intercostal 
lug fitting at the left and right side BL 11.33. The FAA is issuing 
this AD to address any cracking in these areas that could result in 
the loss of limit load capability in a principal structural element, 
the potential inability to restrain the cargo for certain cargo 
configurations, and the potential for a center fuel tank rupture for 
certain cargo configurations under limit load conditions, 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 747-53A2904 RB, dated December 16, 2020, 
do all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
747-53A2904 RB, dated December 16, 2020.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
747-53A2904, dated December 16, 2020, which is referred to in Boeing 
Alert Requirements Bulletin 747-53A2904 RB, dated December 16, 2020.

(h) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Requirements Bulletin 747-53A2904 RB, 
dated December 16, 2020, uses the phrase ``the original issue date 
of Requirements Bulletin 747-53A2904 RB,'' this AD requires using 
``the effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 747-53A2904 RB, 
dated December 16, 2020, 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.

[[Page 48485]]

(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 Related Information. 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, 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 Stefanie Roesli, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 
South 216th St., Des Moines, WA 98198; phone and fax: 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 747-53A2904 RB, dated 
December 16, 2020.
    (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; internet https://www.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: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on August 7, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-18705 Filed 8-30-21; 8:45 am]
BILLING CODE 4910-13-P


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33eaef8ab10d95a52e616ebd66c0b37558fe4c8b8f2519d183e17e5364d9fd6e
Text SHA-256
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