Rule2024-22802
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
October 2, 2024
Effective
October 17, 2024
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, 777-200LR, 777-300ER, and 777F series airplanes. This AD was prompted by a report of potential latent failures of the lightning protection features for the engine fuel feed system. This AD requires repetitive inspections and bond resistance measurement of the bonding jumpers on the first fuel feed tube installed immediately forward of the wing front spar at each of the two engine locations, and applicable corrective 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 89 Issue 191 (Wednesday, October 2, 2024)</title>
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[Federal Register Volume 89, Number 191 (Wednesday, October 2, 2024)]
[Rules and Regulations]
[Pages 80077-80080]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-22802]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-2317; Project Identifier AD-2024-00468-T;
Amendment 39-22856; AD 2024-19-14]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain The Boeing Company Model 777-200, 777-200LR, 777-300ER, and
777F series airplanes. This AD was prompted by a report of potential
latent failures of the lightning protection features for the engine
fuel feed system. This AD requires repetitive inspections and bond
resistance measurement of the bonding jumpers on the first fuel feed
tube installed immediately forward of the wing front spar at each of
the two engine locations, and applicable corrective actions. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective October 17, 2024.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of October 17,
2024.
The FAA must receive comments on this AD by November 18, 2024.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
<bullet> Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> by
searching for and locating Docket No. FAA-2024-2317; 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 street address for Docket
Operations is listed above.
Material Incorporated by Reference:
<bullet> For Boeing material identified in this AD, contact Boeing
Commercial Airplanes, Attention: Contractual & Data Services (C&DS),
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600;
telephone 562-797-1717; website <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
<bullet> You may view this material 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="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2024-2317.
FOR FURTHER INFORMATION CONTACT: Samuel Dorsey, Aviation Safety
Engineer, FAA, 2200 South 216th St, Des Moines, WA 98198; phone: 206-
231-3415; email: <a href="/cdn-cgi/l/email-protection#e9ba88849c8c85c7a3c7ad869b9a8c90a98f8888c78e869f"><span class="__cf_email__" data-cfemail="87d4e6eaf2e2eba9cda9c3e8f5f4e2fec7e1e6e6a9e0e8f1">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments to an address listed under
the ADDRESSES section. Include Docket No. FAA-2024-2317 and Project
Identifier AD-2024-00468-T at the beginning of your comments. The most
helpful comments reference a specific portion of the final rule,
explain the reason for any recommended change, and include supporting
data. The FAA will consider all comments received by the closing date
and may amend this final rule because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
<a href="http://regulations.gov">regulations.gov</a>, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this final rule.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this AD contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this AD, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this AD. Submissions containing CBI should be sent to Samuel
Dorsey, Aviation Safety Engineer, FAA, 2200 South 216th St, Des Moines,
WA 98198; phone: 206-231-3415; email: <a href="/cdn-cgi/l/email-protection#fcaf9d91899990d2b6d2b8938e8f9985bc9a9d9dd29b938a"><span class="__cf_email__" data-cfemail="84d7e5e9f1e1e8aaceaac0ebf6f7e1fdc4e2e5e5aae3ebf2">[email protected]</span></a>. Any
commentary that the FAA receives that is not specifically designated as
CBI will be placed in the public docket for this rulemaking.
Background
In 2023, the FAA received reports of latent failures of the
lightning protection features for the engine fuel feed system on Boeing
Model 747 airplanes. Subsequent analysis has shown that
[[Page 80078]]
similar failures are expected to be present on Model 777 airplanes.
The electrical bonding of the engine fuel feed tube penetrating the
fuel tanks of Boeing Model 777 airplanes and other Boeing airplane
models is the primary design feature to prevent the development of an
ignition source inside the fuel tank during a lightning strike to the
engine nacelle. The fuel feed lightning protection features include the
spar bulkhead fitting that redirects the majority of current during a
lightning event. Separate bonding jumpers outside and inside the fuel
tank provide additional electrical paths for current from lightning
strikes. An additional non-bonding feature, an encapsulation seal over
the spar fitting inside the fuel tank, provides additional protection
from sparking at that location.
In related rulemaking, the FAA issued AD 2023-23-14, Amendment 39-
22616 (88 FR 83494, November 30, 2023) (AD 2023-23-14), to address this
unsafe condition on Model 747 airplanes.
From analysis of reports submitted in connection with AD 2023-23-
14, Boeing and the FAA have determined that Model 777 airplanes are
likely to experience similar encapsulation and bonding failures to
those seen on Model 747 airplanes. On Model 747 airplanes, the bonding
jumper outside the fuel tank is failing at an excessive rate in
addition to the known degradation of the primary electrical bonding
path through the spar fitting. Furthermore, multiple failures of the
spar fitting's encapsulation have been reported. Model 777 airplanes
are expected to be affected to a similar or somewhat lesser degree.
While no reports of failed encapsulations or jumper bonds have been
received for Model 777 airplanes, these features are generally only
inspected and/or replaced conditionally, and they share substantial
similarity to Model 747 airplanes. The fuel feed line encapsulation
seals are located inside the fuel tank and therefore would generally
not be inspected closely unless there was a specific maintenance
concern with the fuel feed fitting. Poor electrical bonding would not
be expected to be detected during on-condition maintenance as
electrical bonding is a function of the installation, and the relevant
component would likely be removed without a resistance measurement.
Upon replacement, the component installation would be measured and
adjusted as necessary to meet the relevant bonding requirements in the
Instructions for Continued Airworthiness.
The spar fitting's encapsulation is designed to isolate any sparks
or arcing generated at the bulkhead fitting during a lightning strike
because of failed electrical bonds from flammable fuel vapors in the
tank. This fitting, including the in-tank coupler connecting the fuel
feed line to the fitting, is the most probable location for sparking
when electrical bonding is poor. Therefore, an unreliable encapsulation
significantly increases the risk of a fuel tank explosion following a
lightning strike to the engine nacelle on an airplane with poor
electrical bonding. Analysis has shown that at least a subset of the
encapsulation failures seen on Model 747 airplanes is expected on Model
777 airplanes.
Model 777 airplanes are equipped with bonding jumpers connecting
the fuel feed line to the airplane structure at two locations on each
wing: immediately forward of the front spar, and in the upper portion
of the engine strut area. These jumpers provide an alternative
lightning current path to the airplane structure, reducing current
passed into the fuel tank. However, airplanes produced with General
Electric Company GE90 series engines were designed without the
additional bonding jumper installation in the engine strut area that
would otherwise sufficiently reduce the risk of a lightning strike that
would result in the unsafe condition. The FAA may issue further
rulemaking to address all Model 777 airplanes including those powered
by Pratt & Whitney and Rolls-Royce engines.
A lightning strike to an engine nacelle combined with a latent
failure of the lightning protection features for the engine fuel feed
system, if not addressed, could result in the potential for ignition
sources inside fuel tanks. This condition, in combination with
flammable fuel vapors, if not addressed, could result in a fuel tank
explosion and consequent loss of the airplane. The FAA is issuing this
AD to address the unsafe condition on these products.
FAA's Determination
The FAA is issuing this AD because the agency has determined the
unsafe condition described previously is likely to exist or develop in
other products of the same type design.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Boeing Multi Operator Message MOM-MOM-24-0463-01B,
dated September 4, 2024. The material specifies procedures for
inspecting and measuring the bond resistance of the bonding jumpers on
the first fuel feed tube installed immediately forward of the wing
front spar at each of the two engine locations, which includes the
following actions:
<bullet> repetitive detailed inspections of the two fuel feed tube
saddle clamps to detect contact between the saddle clamps' metal
components with the fuel tube;
<bullet> repetitive detailed inspections of the engine fuel feed
tube to wing structure bonding jumpers and tube clamps immediately
forward of the wing front spar for damage to the bonding jumpers or any
loose bonding jumper lugs or tube clamps; and
<bullet> repetitive measurement of the electrical bonding
resistance between the wing structure and engine fuel feed tube.
The material also specifies procedures for applicable corrective
actions, which include the following:
<bullet> reworking of the bonding jumper or saddle clamp
installation;
<bullet> replacing saddle clamps whose metal contacts the fuel
tube;
<bullet> cleaning and replacing damaged bonding jumpers and related
hardware; and
<bullet> contacting Boeing for repair instructions if any
resistance measurement exceeds specified limits and doing the repair
instructions.
This material is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in the ADDRESSES section.
AD Requirements
This AD requires accomplishing the actions specified in the
material already described, except for any differences identified as
exceptions in the regulatory text of this AD and except as discussed
under ``Difference Between this AD and the Referenced Material.''
For information on the procedures, see this material at
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2024-2317.
Interim Action
The FAA considers this AD to be an interim action. The manufacturer
is currently developing a more comprehensive inspection that will
address both out-of-tank and in-tank lightning protection features.
Once this inspection is developed, approved, and available, the FAA
might consider additional rulemaking.
Justification for Immediate Adoption and Determination of the Effective
Date
Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C.
551 et seq.) authorizes agencies to dispense with notice and comment
procedures
[[Page 80079]]
for rules when the agency, for ``good cause,'' finds that those
procedures are ``impracticable, unnecessary, or contrary to the public
interest.'' Under this section, an agency, upon finding good cause, may
issue a final rule without providing notice and seeking comment prior
to issuance. Further, section 553(d) of the APA authorizes agencies to
make rules effective in less than thirty days, upon a finding of good
cause.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies forgoing notice and comment prior to adoption of this rule
because a lightning strike to an engine nacelle combined with latent
failures of the lightning protection features for the engine fuel feed
system could result in the potential for ignition sources inside fuel
tanks. This condition, in combination with flammable fuel vapors could
result in a fuel tank explosion and consequent loss of the airplane.
Accordingly, notice and opportunity for prior public comment are
impracticable and contrary to the public interest pursuant to 5 U.S.C.
553(b).
The compliance time in this AD is shorter than the time necessary
for the public to comment and for publication of the final rule. In
addition, the FAA finds that good cause exists pursuant to 5 U.S.C.
553(d) for making this amendment effective in less than 30 days, for
the same reasons the FAA found good cause to forgo notice and comment.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because the FAA has determined
that it has good cause to adopt this rule without notice and comment,
RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 174 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators
----------------------------------------------------------------------------------------------------------------
Inspection and measurement....... 3 work-hours x $85 $0 $255 per inspection $44,370 per
per hour = $255 per cycle. inspection cycle.
inspection cycle.
----------------------------------------------------------------------------------------------------------------
The FAA estimates the following costs to do any on-condition
actions that would be required based on the results of the inspection
and measurement. The FAA has no way of determining the number of
aircraft that might need these actions:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
Replacing saddle clamp........................ 0.5 work-hour x $85 per hour = $3 $45.50
$42.50.
Reworking bonding jumper installation......... 1.0 work-hour x $85 per hour = 0 85
$85.
Replacing bonding jumper...................... 1.0 work-hour x $85 per hour = 3 88
$85.
----------------------------------------------------------------------------------------------------------------
The FAA has received no definitive data on which to base the cost
estimates for the on-condition repair 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, and
(2) Will not affect intrastate aviation in Alaska.
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:
2024-19-14 The Boeing Company: Amendment 39-22856; Docket No. FAA-
2024-2317; Project Identifier AD-2024-00468-T.
(a) Effective Date
This airworthiness directive (AD) is effective October 17, 2024.
[[Page 80080]]
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 777-200, 777-200LR,
777-300ER, and 777F series airplanes, certificated in any category,
with General Electric Company (GE) GE90-76B, GE90-85B, GE90-90B,
GE90-94B, GE90-110B1, and GE90-115B model turbofan engines
installed.
(d) Subject
Air Transport Association (ATA) of America Code 28, Fuel.
(e) Unsafe Condition
This AD was prompted by a report of potential latent failures of
the lightning protection features for the engine fuel feed system.
The FAA is issuing this AD to address such latent failures. A
lightning strike to an engine nacelle combined with latent failures
of the lightning protection features for the engine fuel feed
system, if not addressed, could result in the potential for ignition
sources inside fuel tanks, which, in combination with flammable fuel
vapors, could result in a fuel tank explosion and consequent loss 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: Within 90 days
after the effective date of this AD, or within 1 year after the date
of issuance of the original airworthiness certificate or original
export certificate of airworthiness, whichever comes later, do
detailed inspections and measure the bond resistance of the bonding
jumpers on the fuel feed tube installed immediately forward of the
wing front spar at each of the two engine locations, and do all
applicable corrective actions, in accordance with the Part 2 of the
Work Instructions of Boeing Multi Operator Message MOM-MOM-24-0463-
01B, dated September 4, 2024. All applicable corrective actions must
be done before further flight. Repeat the inspections and bonding
resistance measurement thereafter at intervals not to exceed 1 year.
(h) Exception to Service Information Specifications
(1) Where Boeing Multi Operator Message MOM-MOM-24-0463-01B,
dated September 4, 2024, specifies contacting Boeing for
instructions if a bonding resistance measurement continues to exceed
specified limits after multiple failed corrective action attempts,
this AD requires doing a repair before further flight using a method
approved in accordance with the procedures specified in paragraph
(i) of this AD.
(2) Boeing Multi Operator Message MOM-MOM-24-0463-01B, dated
September 4, 2024, refers to Aircraft Illustrated Parts Catalogue
(AIPC) AIPC 28-11-51-01 in several places; however, the correct AIPC
reference is AIPC 28-11-51-02.
(i) Alternative Methods of Compliance (AMOCs)
(1) The Manager, AIR-520, Continued Operational Safety Branch,
FAA, has the authority to approve AMOCs for this AD, if requested
using the procedures found in 14 CFR 39.19. In accordance with 14
CFR 39.19, send your request to your principal inspector or
responsible Flight Standards Office, as appropriate. If sending
information directly to the manager of the certification office,
send it to the attention of the person identified in paragraph (j)
of this AD. Information may be emailed to <a href="/cdn-cgi/l/email-protection#e5a4a8aaa6a5838484cb828a93"><span class="__cf_email__" data-cfemail="9ddcd0d2deddfbfcfcb3faf2eb">[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, AIR-
520, 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
For more information about this AD, contact Samuel Dorsey,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 206-231-3415; email: <a href="/cdn-cgi/l/email-protection#4714262a32222b690d6903283534223e0721262669202831"><span class="__cf_email__" data-cfemail="7d2e1c1008181153375339120f0e18043d1b1c1c531a120b">[email protected]</span></a>.
(k) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference of the material listed in this paragraph
under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions
required by this AD, unless the AD specifies otherwise.
(i) Boeing Multi Operator Message MOM-MOM-24-0463-01B, dated
September 4, 2024.
(ii) [Reserved]
(3) For Boeing material identified in this AD, contact Boeing
Commercial Airplanes, Attention: Contractual & Data Services (C&DS),
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600;
telephone 562-797-1717; website <a href="http://myboeingfleet.com">myboeingfleet.com</a>.
(4) You may view this material 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 material at the National Archives and
Records Administration (NARA). For information on the availability
of this material at NARA, visit <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#0b6d79256265787b6e687f6264654b656a796a256c647d"><span class="__cf_email__" data-cfemail="91f7e3bff8ffe2e1f4f2e5f8feffd1fff0e3f0bff6fee7">[email protected]</span></a>.
Issued on September 20, 2024.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2024-22802 Filed 9-30-24; 11:15 am]
BILLING CODE 4910-13-P
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