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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0102; Project Identifier AD-2020-01270-E;
Amendment 39-21621; AD 2021-13-16]
RIN 2120-AA64
Airworthiness Directives; General Electric Company Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain General Electric Company (GE) GEnx-2B67, GEnx-2B67/P, and GEnx-
2B67B model turbofan engines. This AD was prompted by a report of a
crack in the lower fuel manifold causing fuel leakage. This AD requires
an ultrasonic inspection (USI) or a fluorescent penetrant inspection
(FPI) of the lower fuel manifold. Depending on the results of the USI
or FPI, this AD requires replacement of the lower fuel manifold with a
part eligible for installation. The FAA is issuing this AD to address
the unsafe condition on these products.
DATES: This AD is effective August 25, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of August 25, 2021.
ADDRESSES: For service information identified in this final rule,
contact General Electric Company, 1 Neumann Way, Cincinnati, OH 45215;
phone: (513) 552-3272; email: aviation.fleetsupport@ae.ge.com; website:
www.ge.com. You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 1200
District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call (781) 238-7759. It is
also available at https://www.regulations.gov by searching for and
locating Docket No. FAA-2021-0102.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0102; 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: Alexei Marqueen, Aviation Safety
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803;
phone: (781) 238-7178; fax: (781) 238-7199; email:
Alexei.T.Marqueen@faa.gov.
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 GE GEnx-2B67,
GEnx-2B67/P, and GEnx-2B67B model turbofan engines. The NPRM published
in the Federal Register on February 26, 2021 (86 FR 11670). The NPRM
was prompted by a report that a GEnx-2B model turbofan engine installed
on a Boeing Model 747-8 airplane was removed from service due to
confirmed fuel leakage from a lower fuel manifold in May 2019. The
operator observed fuel leakage during a routine borescope inspection of
the high-pressure turbine and later confirmed, by ultrasonic
inspection, a crack at brazed block #4 in the pilot secondary fuel
circuit tube on the lower fuel manifold. The FAA received two similar
reports, in March 2020 and May 2020, of a fuel leak from the lower fuel
manifold at brazed block #4. The manufacturer has identified the root
cause of this cracking as low-cycle fatigue due to the abrupt
transition created by the brazed support block pad and its inability to
slide due to thermal loads as intended. In the NPRM, the FAA proposed
to require an USI or an FPI of the lower fuel manifold. Depending on
the results of the USI or FPI, the NPRM proposed to require replacement
of the lower fuel manifold with a part eligible for installation. The
FAA is issuing this AD to address the unsafe condition on these
products.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from five commenters. The commenters were
Air Line Pilots Association, International (ALPA); Boeing Commercial
Airplanes (Boeing); Cathay Pacific Airways Limited (Cathay); GE; and
United Parcel Service (UPS). The following presents the comments
received on the NPRM and the FAA's response to each comment.
Request for Confirmation That Alternate Ultrasonic Probes Are Approved
UPS requested confirmation of whether the alternate probes listed
in Appendix--A, paragraph 4.1.1. of GE GEnx-2B Service Bulletin (SB)
73-0089 R01, dated January 11, 2021 (SB 73-0089 R01), are approved
alternate ultrasonic probes to inspect the lower fuel manifold. UPS
reasoned that Appendix--A, paragraph 4.1.1. of SB 73-0089 R01 indicates
that ultrasonic probes part number (P/N) 00-010012 and P/N 00-010013
are approved alternates for ultrasonic probes P/N 389-085-151 and P/N
389-085-161, respectively. However, the inspection procedure, figures,
and record log in SB 73-0089 R01 only list ultrasonic probe P/N 389-
085-151 and P/N 389-085-161.
The FAA confirms that alternate ultrasonic probes, P/N 00-010012
and P/N 00-010013, are approved alternates, and this AD does not
prohibit their use.
Request for Allowance of Alternative Probe Application Tool
UPS requested that the FAA allow alternative, locally manufactured
probe application tools to aid in the installation of the ultrasonic
probes on the lower fuel manifold. UPS reasoned that during the
installation of the ultrasonic probes on the lower fuel manifold using
probe application tool P/N SGP-156, which is included with the GE
Aircraft Engines Inspection Kit P/N GE-FQAP-677, maintenance noted that
in certain locations, modifying the GE probe application tool provides
easier installation of the ultrasonic probes. UPS commented that all
locally manufactured probe application tools would be removed before
the USI, similar to using probe application tool P/N SGP-156.
This AD does not address requests for specific tool modifications.
However, the FAA will consider requests for alternative methods of
compliance requests in accordance with paragraph (k) of this AD that
include a request for the modifications to the probe application tool.
Request for Add Credit for Previous Action
Cathay requested that this AD provide credit for previous
performance of inspections of the fuel manifold before the effective
date of this AD in accordance with both GE GEnx-2B SB 73-0089 R01,
dated January 11, 2021, and R00, dated May 8, 2020.
The FAA agrees. The instructions for accomplishing the on-wing USI
and FPI have not changed between R00, dated May 8, 2020, and R01, dated
January 11, 2021, of GE GEnx-2B SB 73-0089. The FAA added a Credit for
Previous Actions paragraph to this AD.
Support for the AD
ALPA, Boeing, and GE expressed support for the AD as written.
Conclusion
The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products except for minor editorial changes and any
other changes described previously, this AD is adopted as proposed in
the NPRM. None of the changes will increase the economic burden on any
operator.
Related Service Information Under 1 CFR Part 51
The FAA reviewed GE GEnx-2B SB 73-0089 R01, dated January 11, 2021.
The service information specifies procedures for performing an initial
on-wing visual inspection, a USI, or an FPI of the top main fuel
manifold and the lower fuel manifold. The service information also
specifies procedures for performing repetitive in-shop visual
inspection and FPI for GEnx-2B model turbofan engines. The service
information also provides instructions for replacing the top main fuel
manifold and lower fuel manifold if a crack is found that exceeds the
manufacturer's criteria or if a leak is detected during inspection.
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.
Interim Action
The FAA considers this AD to be an interim action. The design
approval holder is currently developing a modification to address the
unsafe condition identified in this AD. Once this modification is
developed, the FAA might consider additional rulemaking.
Costs of Compliance
The FAA estimates that this AD affects 156 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
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ACTION
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LABOR COST
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PARTS COST
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COST PER PRODUCT
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COST ON U.S. OPERATORS
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| FPI or USI of the lower fuel manifold. |
16 work-hours x $85 per hour = $1,360. |
$0
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$1,360
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$212,160
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The FAA estimates the following costs to do any necessary
replacements 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 this replacement:
On-Condition Costs
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ACTION
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LABOR COST
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PARTS COST
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COST PER PRODUCT
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| Replace the lower fuel manifold |
2 work-hours x $85 per hour = $170. |
$47,730
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$47,900
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The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected individuals.
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
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]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
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