Rule2021-20035
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
September 17, 2021
Effective
October 22, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 777 airplanes. This AD was prompted by a report that an operator found solid rivets with missing heads at the left buttock line 25 on the sloping pressure deck web. This AD requires doing a detailed inspection of the left- and right-side sloping pressure deck at certain stations for any damaged solid rivets, 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 86 Issue 178 (Friday, September 17, 2021)</title>
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[Federal Register Volume 86, Number 178 (Friday, September 17, 2021)]
[Rules and Regulations]
[Pages 51788-51792]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-20035]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0263; Project Identifier AD-2020-01702-T;
Amendment 39-21710; AD 2021-18-09]
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 all
The Boeing Company Model 777 airplanes. This AD was prompted by a
report that an operator found solid rivets with missing heads at the
left buttock line 25 on the sloping pressure deck web. This AD requires
doing a detailed inspection of the left- and right-side sloping
pressure deck at certain stations for any damaged solid rivets, 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 22, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of October 22,
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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. 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="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and locating Docket No.
FAA-2021-0263.
Examining the AD Docket
You may examine the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by
searching for and locating Docket No. FAA-2021-0263; 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: Luis Cortez, Aerospace Engineer,
Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des
Moines, WA 98198; phone and fax: (206) 231-3958; email: <a href="/cdn-cgi/l/email-protection#3f734a564c117e117c504d4b5a4512724a5156457f595e5e11585049"><span class="__cf_email__" data-cfemail="327e475b411c731c715d404657481f7f475c5b48725453531c555d44">[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 all The Boeing Company
Model 777 airplanes. The NPRM published in the Federal Register on
April 9, 2021 (86 FR 18479). The NPRM was
[[Page 51789]]
prompted by a report that an operator found solid rivets with missing
heads at the left buttock line 25 on the sloping pressure deck web. In
the NPRM, the FAA proposed to require doing a detailed inspection of
the left- and right-side sloping pressure deck at certain stations for
any damaged solid rivets, and applicable on-condition actions. The FAA
is issuing this AD to address damaged or missing solid rivet heads on
the sloping pressure deck web, which could result in loss of sloping
pressure deck panels, causing decompression and pressure loss, and loss
of the hydraulic systems in the area for wheel brakes (both normal and
alternate) and steering, and potentially leading to runway departure
and adversely affecting the structural integrity of the airplane.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from four commenters, including Boeing,
American Airlines (AA), FedEx, and United Airlines (UAL). The following
presents the comments received on the NPRM and the FAA's response to
each comment.
Request To Revise the On-Condition Actions Statement
Boeing requested a revision to the on-condition actions statement
in the third sentence of the ``Related Service Information Under 1 CFR
part 51'' paragraph of the NPRM. Boeing stated that the repetitive
detailed inspections cover ``two rows of fasteners common to the
affected stiffener,'' instead of ``two rows of blind fasteners and
solid rivets common to the affected stiffener.'' Boeing commented that
the blind fastener repair option is allowed only under Condition 2 of
Boeing Alert Requirements Bulletin 777-53A0093 RB, dated November 24,
2020, which is limited to findings of a maximum of nine damaged rivets
within the same stiffener. Boeing commented that the damage rivets must
be within the same fastener row, and therefore, the compliance action
does not allow for blind fasteners to be installed in both fastener
rows of an affected stiffener. Boeing commented that the revised
language improves clarity of the on-condition actions because it does
not imply that blind fasteners can be installed in both fastener rows
of an affected stiffener.
The FAA agrees to revise the on-condition actions statement in the
``Related Service Information Under 1 CFR part 51'' paragraph of this
final rule for the reasons provided above; the FAA has revised this
final rule accordingly.
Request To Revise Cost of Compliance Paragraph
Boeing requested a revision to the on-condition work-hours for
replacing a blind fastener. Boeing stated that the blind fastener
replacement does not require internal access, and therefore, the 328
work-hours can be reduced to 11 work-hours as noted in Boeing
Information Notice 777-53A0093 IN 01, dated January 27, 2021.
The FAA agrees to revise the on-condition work-hours for replacing
a blind fastener for the reason provided above; this final rule has
been revised accordingly.
Request To Clarify the Applicability
AA asked if the rivet problems specified in the NPRM affect any
airplanes in the AA livery, particularly N-numbers (nose numbers) so it
can keep better track on preflights.
For clarification, this AD does affect AA airplanes because its
fleet includes Model 777-200 and -300ER airplanes. This AD applies to
all Model 777-200, -200LR, -300, -300ER, and 777F airplanes, as
specified in paragraph (c) of this AD. Since all Model 777 airplanes
are affected, it is not necessary to identify airplanes by N-numbers.
The FAA has not changed this AD in this regard.
Request To Revise the Compliance Time
FedEx Express (FedEx) agreed with the intent of the proposed AD,
but found the 16-month compliance time for the initial inspection does
not align with its heavy maintenance visits and requested an extension.
FedEx stated that its current heavy maintenance visits would be the
suitable time to accomplish the actions in the proposed AD, and that
accomplishing the initial inspection in the proposed AD may require
performing special maintenance visits. FedEx commented that it
currently has 26 Model 777F airplanes that have accumulated more than
32,000 flight hours, and therefore, will be required to accomplish the
initial inspection within the 16-month initial compliance time.
FedEx also commented that since Boeing found the missing rivet
heads from a retired Model 777-200 airplane, the current in-service
Model 777 airplanes can operate with missing rivets without
experiencing adverse structural complications since the issue was not
discovered until after that airplane retired from service.
The FAA disagrees with the commenter's request to extend the
initial compliance time. The FAA cannot assume that Model 777 airplanes
can operate with missing rivet heads without experiencing adverse
structural complications. The FAA determined that the compliance time,
as proposed, represents the maximum interval of time allowable for the
affected airplanes to continue to safely operate before the initial and
repetitive inspections and on-condition actions are done. If the
inspection interval were based on maintenance schedules, which vary
among operators, there would be no assurance that the airplane would be
inspected and repaired during that maximum interval. In addition, in
developing an appropriate compliance time, the FAA coordinated with the
manufacturer to provide a compliance time with an acceptable level of
safety. However, under the provisions of paragraph (i) of this AD, the
FAA will consider requests for approval of an extension of the
compliance time, 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 Required Service Information
FedEx requested that the FAA revise note 1 to paragraph (g) in the
proposed AD to clarify that the proposed AD requires accomplishment of
the actions only specified in Boeing Alert Requirements Bulletin 777-
53A0093 RB, dated November 24, 2020. FedEx stated that note 1 does not
clearly distinguish the required actions from the guidance service
information for accomplishing the actions in the proposed AD.
The FAA disagrees with the commenter's request to change the note.
For clarification, paragraph (g) of this AD states the required actions
for applicable airplanes, and only specifies to do all applicable
actions identified in, and in accordance with, the Accomplishment
Instructions of Boeing Alert Requirements Bulletin 777-53A0093 RB,
dated November 24, 2020. The FAA clearly states that note 1 to
paragraph (g) of this AD is guidance and Boeing Alert Service Bulletin
777-53A0093, dated November 24, 2020, is only referred to in that note.
The FAA has not changed this AD in this regard.
Request To Clarify Repair Instructions
UAL indicated support for the NPRM, but requested clarification as
to what to do if a Condition 4 is found in one stiffener and a
Condition 3 is found in
[[Page 51790]]
another stiffener as referenced in Boeing Alert Service Bulletin 777-
53A0093, dated November 24, 2020. UAL stated that Condition 4 requires
operators to contact Boeing and request repair instructions and to do
the repair if any damaged rivet is found on both fastener rows within
the same stiffener.
In addition, UAL requested the following clarifications.
<bullet> When contacting Boeing, should operators provide all
details of affected stiffeners regardless of the condition identified
in Boeing Alert Service Bulletin 777-53A0093, dated November 24, 2020?
UAL commented that Boeing Alert Service Bulletin 777-53A0093, dated
November 24, 2020, appears to request details associated with a
specific stiffener only.
<bullet> Where a Condition 4 discrepancy is present, is it
acceptable to continue with the repair of an adjacent Condition 3
stiffener discrepancy or is further manufacturer approval required?
UAL stated that it assumes that the conservative approach would be
for the operator to provide all details of affected stiffeners to the
manufacturer and then the manufacturer will provide approval to repair
both Conditions 3 and 4, as referenced in Boeing Alert Service Bulletin
777-53A0093, dated November 24, 2020. UAL asserted that clarification
will help operators determine which information is required by the
manufacturer to make a repair assessment, and it will also provide
clarification as to what to do in the event of a parallel process
involving both Condition 3 and Condition 4 repair.
The FAA provides the following clarification for the commenter.
This AD requires operators to use Boeing Alert Requirements Bulletin
777-53A0093 RB, dated November 24, 2020, to perform the actions
required in this AD. Boeing Alert Service Bulletin 777-53A0093, dated
November 24, 2020, is for guidance only. Boeing Alert Requirements
Bulletin 777-53A0093 RB, dated November 24, 2020, does not specify any
limitations on a Condition 3 repair based on any conditions found on
another stiffener. When a Condition 3 is found, the FAA finds no issues
with continuing with the Condition 3 repair of replacing all solid
rivets even in the event a Condition 4 is found in an adjacent
stiffener. Regarding the question on the details to provide to Boeing
for a repair, as specified in Note 4. of 5.A., ``General Information,''
of Boeing Alert Requirements Bulletin 777-53A0093 RB, dated November
24, 2020, operators can refer to Boeing Service Letter 777-SL-51-013,
Damage Reporting and Repair Plan/Design Guidelines, which describes
what information must be provided to Boeing before a structural repair
can be provided. The structural repair must be approved by the FAA or
the Boeing Company Organization Designation Authorization (ODA) as
specified in paragraph (h)(2) of this AD. The FAA has not revised this
AD in this regard.
Conclusion
The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting this AD as
proposed. 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 777-53A0093 RB,
dated November 24, 2020. This service information specifies procedures
for doing a detailed inspection of the left- and right-side sloping
pressure deck from station (STA) 1245 to STA 1287 for any damaged
(i.e., missing solid rivet heads, cracking or deformation of the solid
rivet, or gaps between the solid rivet head and the sloping pressure
deck surface) solid rivets, and applicable on-condition actions. On-
condition actions include repeating the detailed inspection of the
left-and right-side sloping pressure deck from STA 1245 to STA 1287 for
any damaged solid rivet; repetitive detailed inspections of two rows of
fasteners common to the affected stiffener for any damaged solid rivet
or damaged blind fastener; replacing solid rivets or blind fasteners;
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 224 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
----------------------------------------------------------------------------------------------------------------
Detailed inspections............. Up to 384 work- $0 Up to $32,640...... Up to $7,311,360.
hours x $85 per
hour = Up to
$32,640.
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The FAA estimates the following costs to do any necessary
replacements or inspections 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 replacements or inspections:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product
----------------------------------------------------------------------------------------------------------------
Replacement (solid fastener)......... 338 work-hours x $85 Up to $3,200........... Up to $31,930.
per hour = $28,730.
Replacement (blind fastener)......... 11 work-hour x $85 per Up to $450............. Up to $1,385.
hour = $935.
Repetitive inspections of fastener 326 work-hours x $85 $0 per inspection cycle $27,710 per inspection
rows. per hour = $27,710 per cycle.
inspection cycle.
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[[Page 51791]]
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:
2021-18-09 The Boeing Company: Amendment 39-21710; Docket No. FAA-
2021-0263; Project Identifier AD-2020-01702-T.
(a) Effective Date
This airworthiness directive (AD) is effective October 22, 2021.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all The Boeing Company Model 777-200, -200LR,
-300, -300ER, and 777F airplanes, certificated in any category.
(d) Subject
Air Transport Association (ATA) of America Code 53, Fuselage.
(e) Unsafe Condition
This AD was prompted by a report that an operator found solid
rivets with missing heads at the left buttock line 25 on the sloping
pressure deck web. The FAA is issuing this AD to address damaged or
missing solid rivet heads on the sloping pressure deck web, which
could result in loss of sloping pressure deck panels, causing
decompression and pressure loss, and loss of the hydraulic systems
in the area for wheel brakes (both normal and alternate) and
steering, and potentially leading to runway departure and adversely
affecting 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 777-53A0093 RB, dated November 24, 2020,
do all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
777-53A0093 RB, dated November 24, 2020.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
777-53A0093, dated November 24, 2020, which is referred to in Boeing
Alert Requirements Bulletin 777-53A0093 RB, dated November 24, 2020.
(h) Exceptions to Service Information Specifications
(1) Where Boeing Alert Requirements Bulletin 777-53A0093 RB,
dated November 24, 2020, uses the phrase ``the original issue date
of 777-53A0093 RB'' or ``the original issue date of Requirements
Bulletin 777-53A0093 RB,'' this AD requires using ``the effective
date of this AD,'' except where Alert Requirements Bulletin 777-
53A0093 RB, dated November 24, 2020, uses the phrase ``the original
issue date of Requirements Bulletin 777-53A0093 RB'' in a note or
flag note.
(2) Where Boeing Alert Requirements Bulletin 777-53A0093 RB,
dated November 24, 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.
(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: <a href="/cdn-cgi/l/email-protection#1e27335f5053334d7b7f6a6a727b335f5d51335f53515d334c7b6f6b7b6d6a6d5e787f7f30797168"><span class="__cf_email__" data-cfemail="3e07137f7073136d5b5f4a4a525b137f7d71137f73717d136c5b4f4b5b4d4a4d7e585f5f10595148">[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 Luis Cortez,
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200
South 216th St., Des Moines, WA 98198; phone and fax: (206) 231-
3958; email: <a href="/cdn-cgi/l/email-protection#ca86bfa3b9e48be489a5b8beafb0e787bfa4a3b08aacababe4ada5bc"><span class="__cf_email__" data-cfemail="276b524e5409660964485553425d0a6a52494e5d6741464609404851">[email protected]</span></a>.
(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 777-53A0093 RB, dated
November 24, 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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
(4) You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 2200
South 216th
[[Page 51792]]
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 <a href="/cdn-cgi/l/email-protection#5f392d7136312c2f3a3c2b3630311f313e2d3e71383029"><span class="__cf_email__" data-cfemail="086e7a2661667b786d6b7c6167664866697a69266f677e">[email protected]</span></a>, or go to: <a href="https://www.archives.gov/federal-register/cfr/ibr-locations.html">https://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued on August 25, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2021-20035 Filed 9-16-21; 8:45 am]
BILLING CODE 4910-13-P
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