Rule2021-15029
Airworthiness Directives; The Boeing Company Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
July 15, 2021
Effective
August 19, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777 airplanes. This AD was prompted by reports indicating that during investigation of a fuel leak, fatigue cracking was found on the forward inboard side of the fuel tank access door cutouts on the left and right lower wing skin. The cause of the cracking is attributed to corrosion damage. This AD requires repetitive inspections for any existing repair of the wing lower skin fuel tank and dry bay access door cutouts on the left and right lower wing skin, and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
<html>
<head>
<title>Federal Register, Volume 86 Issue 133 (Thursday, July 15, 2021)</title>
</head>
<body><pre>
[Federal Register Volume 86, Number 133 (Thursday, July 15, 2021)]
[Rules and Regulations]
[Pages 37221-37224]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-15029]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0981; Project Identifier AD-2020-00919-T;
Amendment 39-21615; AD 2021-13-10]
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 777 airplanes. This AD was prompted by
reports indicating that during investigation of a fuel leak, fatigue
cracking was found on the forward inboard side of the fuel tank access
door cutouts on the left and right lower wing skin. The cause of the
cracking is attributed to corrosion damage. This AD requires repetitive
inspections for any existing repair of the wing lower skin fuel tank
and dry bay access door cutouts on the left and right lower wing skin,
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 19, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 19,
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-2020-0981.
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-2020-0981; 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 A. Cortez-Muniz, 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#d0bca5b9a3feb1feb3bfa2a4b5aafdbda5beb9aa90b6b1b1feb7bfa6"><span class="__cf_email__" data-cfemail="e8849d819bc689c68b879a9c8d92c5859d868192a88e8989c68f879e">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain The Boeing
Company Model 777 airplanes. The NPRM published in the Federal Register
on November 18, 2020 (85 FR 73430). The NPRM was prompted by reports
indicating that during investigation of a fuel leak, fatigue cracking
was found on the forward inboard side of the fuel tank access door
cutouts on the left and right lower wing skin. The cause of the
cracking is attributed to corrosion damage. In the NPRM, the FAA
proposed to require repetitive inspections for any existing repair of
the wing lower skin fuel tank and dry bay access door cutouts on the
left and right lower wing skin, and applicable on-condition actions.
The FAA is issuing this AD to address fatigue cracking, which could
result in the inability of a principal structural element to sustain
limit load, and consequent reduced structural integrity of the
airplane.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from Boeing and United Airlines. Those
commenters supported the NPRM without change.
The FAA received additional comments from six commenters, including
AeroLogic, Air France, American Airlines, Emirates, FedEx Express
(FedEx), and one individual. The following presents the comments
received on the NPRM and the FAA's response to each comment.
Request To Revise Compliance Time
AeroLogic, Air France, American Airlines, and Emirates asked that
the FAA re-evaluate and extend the initial and repetitive calendar-
based compliance times in the proposed AD to match heavy maintenance
intervals. The commenters stated that the 1,125-day compliance time
does not align with existing MPD intervals of 3,000 days and 4,500 days
or the existing heavy maintenance intervals. One commenter stated that,
as a long-range freight specialist it has an average flight hour/flight
cycle ratio of 6.0 to 6.3, thus reaching the flight hour LOV of the
Model 777F before reaching the flight cycle utilization that the
aircraft with crack findings had at the time of crack detection. The
commenters also stated that more frequent opening and closing of the
access doors could increase the chance of corrosion. although the
airplane with the initial crack finding was 19 years old at the time
cracking was found, and Boeing reported that only minimal corrosion was
found during lab testing of the cracking.
The FAA does not agree with the requests to extend the compliance
time. The compliance times were coordinated with the design approval
holder based on its analysis and fleet findings. Additionally, the
commenters did not provide substantiation data that shows that the
proposed extended inspection intervals provide adequate crack
detection. 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 extension would provide an acceptable level of safety. This AD has
not been changed in this regard.
Request To Change Exception
Air France stated that paragraph (h)(1) of the proposed AD would
require using ``the effective date of this AD,'' except where Boeing
Alert Requirements Bulletin 777-57A0118 RB, dated June 23, 2020, uses
the phrase ``the original issue date of Requirements Bulletin 777-
57A0118 RB'' in a note or flag note. Air France noted that making the
exception depend on a note or flag note is confusing. Air France asked
that the FAA change the exception to apply throughout the proposed AD
requirements instead of depending on
[[Page 37222]]
where the phrase ``the original issue date of Requirements Bulletin
777-57A0118 RB'' is used.
The FAA agrees to change the exception in paragraph (h)(1) of this
AD. The exception specified in paragraph (h)(1) of the proposed AD was
intended to apply only to certain dates referenced in Boeing Alert
Requirements Bulletin 777-57A0118 RB, dated June 23, 2020. The
exception applies to the associated date in the Effectivity paragraph
and the Condition and Compliance columns of tables 1 through 10 of
paragraph 1.E., ``Compliance,'' and not to flag note (c) in the tables.
Repairs accomplished relative to the original issue date of
Requirements Bulletin 777-57A0118 RB, as specified in flag note (c) in
those tables, do not need an exception for compliance with this AD. The
FAA has changed paragraph (h)(1) of this AD accordingly.
Request To Change Estimated Work Hours for Inspection
FedEx stated that the hours estimated for ``the inspection'' in the
Costs of Compliance section of the NPRM is lower than its forecast of
80 work-hours and 60 elapsed hours. FedEx noted that the NPRM specified
only 34 work-hours.
The FAA infers that the commenter is asking to increase the work
hours for the general visual inspections specified in the Costs of
Compliance section of this AD to 80 work-hours. We do not agree. The
estimate of 34 work-hours includes access and close for accomplishing
the general visual inspections. The FAA recognizes that additional on-
condition inspections could be required, depending on the results of
the general visual inspection. However, since the FAA has no way of
determining the number of aircraft that might need these on-condition
inspections, the hours and cost estimates for the additional
inspections are provided in the on-condition actions table on a per-
airplane basis. This AD has not been changed in this regard.
Request To Allow Detailed Inspections for Certain Airplanes
One individual asked that the FAA allow detailed and high frequency
eddy current (HFEC) inspections for airplanes in Group 3, Condition 17
(for the right wing), similar to the detailed and HFEC inspections
allowed for airplanes in Group 3, Condition 14 (for the left wing). The
commenter observed that Condition 14 specifies detailed and HFEC
inspections, whereas Condition 17 specifies contacting Boeing. The
commenter stated that these conditions are the same and symmetrical for
the left- and right-hand wings.
The FAA does not agree with the commenter's request. Configurations
on Group 3 airplanes may be different on the left and right sides due
to previously approved repairs or production changes. The inspection
procedures were coordinated with the design approval holder regarding
the airplane configurations. Therefore, this AD has not been changed in
this regard.
Request To Clarify Cost Estimate
AeroLogic stated that the proposed compliance time would result in
an economic impact that was not considered in the operator burden
provided in the cost estimate.
The FAA provides the following clarification: The cost information
describes only the direct costs of the specific actions required by
this AD. Based on the best data available, the manufacturer provided
the number of work hours necessary to do the required actions. This
number represents the time necessary to perform only the actions
actually required by this AD. We recognize that, in doing the actions
required by an AD, operators might incur incidental costs in addition
to the direct costs. The cost analysis in AD rulemaking actions,
however, typically does not include incidental costs such as the time
necessary for planning or time necessitated by other administrative
actions. Those incidental costs, which might vary significantly among
operators, are almost impossible to calculate.
Aerologic also stated that the aircraft maintenance manual (AMM)
recommends using new gaskets to prevent fuel leaks after each tank
access. Therefore, the parts cost should be estimated with up to 240
USD per gasket. At 18 Access Doors opened for every repeat inspection,
this sums up to 4,320 USD per aircraft for each inspection cycle.
The FAA does not agree to change the estimated parts costs, as the
actions in the AMM are not required by this AD.
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, 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 777-57A0118 RB,
dated June 23, 2020. The service information describes procedures for
repetitive general visual inspections for any existing repair of the
fuel tank access door cutouts on the left and right lower wing skin,
and applicable on-condition actions. On-condition actions include
detailed and HFEC inspections for any corrosion, fretting, and
cracking; a blend out of corrosion or fretting that meets certain
criteria; 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 221 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
General visual inspection........ Up to 34 work-hours $0 Up to $2,890 per Up to $638,690 per
x $85 per hour = inspection cycle. inspection cycle.
Up to $2,890 per
inspection cycle.
----------------------------------------------------------------------------------------------------------------
The FAA estimates the following costs to do any necessary on-
condition actions that would be required. The FAA has no way of
determining the number of aircraft that might need these on-condition
actions:
[[Page 37223]]
Estimated Costs of On-Condition Actions *
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Blend out of corrosion or 2 work-hours x $85 $0 $170 per blend out. $170 per blend out.
fretting. per hour = $170
per blend out.
Repair of crack 0.2 inch or less 2 work-hours x $85 0 $170 per crack..... $170 per crack.
with no blend repair or keyway per hour = $170
trim modification. per crack.
Detailed and HFEC inspections.... 2 work-hours x $85 0 $170 per access $170 per access
per hour = $170 door cutout. door cutout.
per access door
cutout.
----------------------------------------------------------------------------------------------------------------
* The FAA has received no definitive data on which to base the cost estimates for the on-condition repairs
specified in this AD that require obtaining an alternative method of compliance (AMOC).
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:
2021-13-10 The Boeing Company: Amendment 39-21615; Docket No. FAA-
2020-0981; Project Identifier AD-2020-00919-T.
(a) Effective Date
This airworthiness directive (AD) is effective August 19, 2021.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 777-200, -200LR, -
300, -300ER, and 777F series airplanes, certificated in any
category, as identified in Boeing Alert Requirements Bulletin 777-
57A0118 RB, dated June 23, 2020.
(d) Subject
Air Transport Association (ATA) of America Code 57, Wings.
(e) Unsafe Condition
This AD was prompted by reports indicating that during
investigation of a fuel leak, fatigue cracking was found on the
forward inboard side of the fuel tank access door cutouts on the
left and right lower wing skin. The cause of the cracking is
attributed to corrosion damage. The FAA is issuing this AD to
address such cracking, which could result in the inability of a
principal structural element to sustain limit load, and consequent
reduced 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 777-57A0118 RB, dated June 23, 2020, do
all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
777-57A0118 RB, dated June 23, 2020.
Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
777-57A0118, dated June 23, 2020, which is referred to in Boeing
Alert Requirements Bulletin 777-57A0118 RB, dated June 23, 2020.
(h) Exceptions to Service Information Specifications
(1) Where the ``Effectivity'' paragraph, and the Condition and
Compliance Time columns of the tables in the ``Compliance''
paragraph, of Boeing Alert Requirements Bulletin 777-57A0118 RB,
dated June 23, 2020, use the phrase ``the original issue date of
Requirements Bulletin 777-57A0118 RB,'' this AD requires using ``the
effective date of this AD.''
(2) Where Boeing Alert Requirements Bulletin 777-57A0118 RB,
dated June 23, 2020, 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.
(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 paragraph (j)(1) of this AD. Information may be
emailed to: <a href="/cdn-cgi/l/email-protection#281105696665057b4d495c5c444d05696b67056965676b057a4d595d4d5b5c5b684e4949064f475e"><span class="__cf_email__" data-cfemail="2e17036f6063037d4b4f5a5a424b036f6d61036f63616d037c4b5f5b4b5d5a5d6e484f4f00494158">[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,
[[Page 37224]]
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
For more information about this AD, contact Luis A. Cortez-
Muniz, 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#731f061a005d125d101c010716095e1e061d1a09331512125d141c05"><span class="__cf_email__" data-cfemail="18746d716b3679367b776a6c7d6235756d767162587e7979367f776e">[email protected]</span></a>.
(k) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
(i) Boeing Alert Requirements Bulletin 777-57A0118 RB, dated
June 23, 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 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#cfa9aaabbdaaa8e1a3aaa8aea38fa1aebdaee1a8a0b9"><span class="__cf_email__" data-cfemail="84e2e1e0f6e1e3aae8e1e3e5e8c4eae5f6e5aae3ebf2">[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 June 10, 2021.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2021-15029 Filed 7-14-21; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on July 15, 2021.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.