[Federal Register Volume 86, Number 37 (Friday, February 26, 2021)]
[Proposed Rules]
[Pages 11670-11673]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-03708]


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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]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain General Electric Company (GE) GEnx-2B67, GEnx-2B67/P, and 
GEnx-2B67B model turbofan engines. This proposed AD was prompted by a 
report of a crack in the lower fuel manifold causing fuel leakage. This 
proposed AD would require 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 proposed AD would 
require replacement of the lower fuel manifold with a part eligible for 
installation. The FAA is proposing this AD to address the unsafe 
condition on these products.

DATES: The FAA must receive comments on this proposed AD by April 12, 
2021.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     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.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact General 
Electric Company, 1 Neumann Way, Cincinnati, OH 45215; phone: (513) 
552-3272; email: [email protected]; 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.

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 NPRM, any comments 
received, and other information. The street address for Docket 
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Mehdi Lamnyi, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7743; fax: (781) 238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2021-0102; Project Identifier 
AD-2020-01270-E'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, 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 proposal 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 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this NPRM.

[[Page 11671]]

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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to Mehdi 
Lamnyi, Aviation Safety Engineer, ECO Branch, FAA, 1200 District 
Avenue, Burlington, MA 01803. Any commentary that the FAA receives 
which is not specifically designated as CBI will be placed in the 
public docket for this rulemaking.

Background

    The FAA received 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. This condition, if not addressed, could result in 
failure of the fuel manifold, engine fire, and damage to the airplane.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed GE GEnx-2B Service Bulletin (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 the ADDRESSES section.

Proposed AD Requirements in This NPRM

    This proposed AD would require performing either a USI, an on-wing 
spot FPI, or an in-shop FPI of the lower fuel manifold, part number (P/
N) 2619M58G01, at the locations adjacent to the five support block pads 
to detect cracks. Depending on the results of the inspection, this AD 
may require removing the lower fuel manifold from service and replacing 
it with a part eligible for installation.

Differences Between This Proposed AD and the Service Information

    GE GEnx-2B SB 73-0089 R01, dated January 11, 2021, describes 
procedures for performing an initial on-wing visual inspection of the 
top main fuel manifold and the lower fuel manifold, followed by a USI 
or an FPI. This service information describes procedures for a 
repetitive in-shop visual inspection and FPI of the top main fuel 
manifold and the lower fuel manifold. This service information also 
provides instructions for replacing the top main fuel manifold or the 
lower fuel manifold if a crack is discovered that exceeds the criteria 
established by the manufacturer or if a leak is detected during 
inspection.
    This proposed AD would not require inspection or replacement of the 
top main fuel manifold or a visual inspection of the lower fuel 
manifold. This proposed AD would also not require the repetitive in-
shop visual inspection and FPI of the top main fuel manifold and the 
lower fuel manifold. This proposed AD would require a USI, an on-wing 
spot FPI, or an in-shop FPI of the lower fuel manifold and, depending 
on the results of the inspection, replacement of the lower fuel 
manifold with a part eligible for installation. Reports received by the 
FAA indicate that fuel leakage has occurred on the lower fuel manifold. 
Based on these reports, the FAA is not requiring inspection of the top 
main fuel manifold.

Interim Action

    The FAA considers this proposed AD would 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, if adopted as proposed, would 
affect 156 engines installed on airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
FPI or USI of the lower fuel manifold.  16 work-hours x $85 per               $0          $1,360        $212,160
                                         hour = $1,360.
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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 
proposed inspection. The FAA has no way of determining the number of 
aircraft that might need this replacement:

[[Page 11672]]



                                               On-Condition Costs
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                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace the lower fuel manifold...............  2 work-hours x $85 per hour =            $47,730         $47,900
                                                 $170.
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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 
proposed AD may be covered under warranty, thereby reducing the cost 
impact on affected operators.

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

    The FAA determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would 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 Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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:

General Electric Company: Docket No. FAA-2021-0102; Project 
Identifier AD-2020-01270-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by April 12, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) GEnx-2B67, 
GEnx-2B67/P, and GEnx-2B67B model turbofan engines with lower fuel 
manifold, part number (P/N) 2619M58G01, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7310, Engine Fuel 
Distribution.

(e) Unsafe Condition

    This AD was prompted by a report of a crack in the lower fuel 
manifold. The FAA is issuing this AD to detect cracking of the lower 
fuel manifold. The unsafe condition, if not addressed, could result 
in failure of the fuel manifold, engine fire, and damage to the 
airplane.

(f) Compliance

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

(g) Required Actions

    (1) Within the compliance time specified in Table 1 to paragraph 
(g)(1) of this AD, perform either an ultrasonic inspection (USI), an 
on-wing spot fluorescent penetrant inspection (FPI), or an in-shop 
FPI of the lower fuel manifold, P/N 2619M58G01, in accordance with 
paragraph (g)(1)(i), (ii), or (iii) of this AD, as applicable.

              Table 1 to Paragraph (g)(1)--Compliance Time
------------------------------------------------------------------------
 Lower fuel manifold cycles since
             new (CSN)                         Compliance time
------------------------------------------------------------------------
Less than 1,700 CSN...............  After the lower fuel manifold has
                                     accumulated 1,700 CSN, but before
                                     it exceeds 2,200 CSN.
1,700 CSN or more.................  Within 500 engine flight cycles
                                     (FCs) after the effective date of
                                     this AD.
------------------------------------------------------------------------

    (i) Perform a USI of the lower fuel manifold at the locations 
adjacent to the five support block pads to detect cracks in 
accordance with paragraph 4. Appendix--A of GEnx-2B Service Bulletin 
(SB) 73-0089 R01, dated January 11, 2021.
    (ii) Perform an on-wing spot FPI of the lower fuel manifold at 
the five brazed block joints to detect cracks. Guidance on 
performing the spot FPI can be found in paragraph 3.B.(6)(a) of 
GEnx-2B SB 73-0089 R01, dated January 11, 2021.
    (iii) Perform an in-shop FPI of the lower fuel manifold at the 
five brazed block joints to detect cracks. Guidance on performing 
the FPI can be found in paragraph 3.C.(4) of GEnx-2B SB 73-0089 R01, 
dated January 11, 2021.
    (2) If a crack or rejectable indication is found during the USI, 
on-wing spot FPI, or in-shop FPI required by paragraphs (g)(1)(i), 
(ii), and (iii) of this AD, before further flight, remove the lower 
fuel manifold from service and replace it with a part eligible for 
installation.

(h) Definition

    For the purpose of this AD, a part eligible for installation is:
    (1) Any serviceable lower fuel manifold, P/N 2619M58G01, with 
less than 1,700 CSN, or
    (2) Any lower fuel manifold, P/N 2619M58G01, with 1,700 CSN or 
more that has been inspected in accordance with paragraph (g)(1)(i), 
(ii), or (iii) of this AD and a crack or rejectable indication was 
not found, or
    (3) Any approved lower fuel manifold with a part number other 
than P/N 2619M58G01.

[[Page 11673]]

(i) No Reporting Requirements

    The reporting requirements specified in paragraph 4. Appendix--A 
of GE GEnx-2B SB 73-0089 R01, dated January 11, 2021, are not 
required by this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO 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 local Flight Standards District 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. You may email your request to: 
[email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    (1) For more information about this AD, contact Mehdi Lamnyi, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7743; fax: (781) 238-7199; 
email: [email protected].
    (2) For service information identified in this AD, contact 
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; 
phone: (513) 552-3272; email: [email protected]; 
website: www.ge.com. You may view this referenced 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.

    Issued on February 18, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-03708 Filed 2-25-21; 8:45 am]
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