Rule2022-03040
Airworthiness Directives; General Electric Company Turbofan Engines
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
February 14, 2022
Effective
March 21, 2022
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) GEnx-1B and GEnx-2B model turbofan engines. This AD was prompted by the manufacturer's report of two findings of sheared compressor discharge pressure (CDP) bolts during engine shop visits. This AD requires initial and repetitive inspections of the CDP bolted joint and, depending on the findings, a piece part inspection of the stages 6-10 compressor rotor spool, CDP seal, and high-pressure turbine (HPT) rotor stage 1 disk. As a terminating action, this AD requires operators to reassemble the CDP bolted joint using a specific torque wrench. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 87 Issue 30 (Monday, February 14, 2022)</title>
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[Federal Register Volume 87, Number 30 (Monday, February 14, 2022)]
[Rules and Regulations]
[Pages 8178-8180]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-03040]
[[Page 8178]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0831; Project Identifier AD-2021-00712-E;
Amendment 39-21933; AD 2022-03-16]
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-1B and GEnx-2B model
turbofan engines. This AD was prompted by the manufacturer's report of
two findings of sheared compressor discharge pressure (CDP) bolts
during engine shop visits. This AD requires initial and repetitive
inspections of the CDP bolted joint and, depending on the findings, a
piece part inspection of the stages 6-10 compressor rotor spool, CDP
seal, and high-pressure turbine (HPT) rotor stage 1 disk. As a
terminating action, this AD requires operators to reassemble the CDP
bolted joint using a specific torque wrench. The FAA is issuing this AD
to address the unsafe condition on these products.
DATES: This AD is effective March 21, 2022.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of March 21,
2022.
ADDRESSES: For service information identified in this final rule,
contact General Electric Company, 1 Neumann Way, Cincinnati, OH 45215;
phone: (513) 552-3272; email: <a href="/cdn-cgi/l/email-protection#8aebfce3ebfee3e5e4a4ece6efeffef9fffafae5f8fecaebefa4edefa4e9e5e7"><span class="__cf_email__" data-cfemail="e283948b83968b8d8ccc848e878796919792928d9096a28387cc8587cc818d8f">[email protected]</span></a>; website:
<a href="http://www.ge.com">www.ge.com</a>. 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 (817) 222-5110. It is
also available at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and
locating Docket No. FAA-2021-0831.
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-2021-0831; 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:
<a href="/cdn-cgi/l/email-protection#66270a031e030f4832482b071417130303082600070748010910"><span class="__cf_email__" data-cfemail="2869444d504d41067c0665495a595d4d4d46684e4949064f475e">[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 GE GEnx-1B and
GEnx-2B model turbofan engines. The NPRM published in the Federal
Register on October 28, 2021 (86 FR 59667). The NPRM was prompted by a
report from the manufacturer of two findings of sheared CDP bolts at
engine shop visits during disassembly of the CDP bolted joint on GEnx-
1B70/75/P2 and GEnx-2B67/P model turbofan engines. Subsequent
investigation by the manufacturer determined that the fracture and
liberation of the CDP bolts was caused by the inadvertent over-torque
condition of the bolts during assembly and reassembly with a 11C4525P01
torque fixture or during assembly with a 11C4629P01 torque wrench. In
one finding, the fractured CDP bolt caused damage to the stages 6-10
compressor rotor spool, CDP seal, and HPT rotor stage 1 disk. In the
NPRM, the FAA proposed to require initial and repetitive inspections of
the CDP bolted joint and, depending on the findings, a piece part
inspection of the stages 6-10 compressor rotor spool, CDP seal, and HPT
rotor stage 1 disk. As a terminating action, the NPRM also proposed to
require operators to reassemble the CDP bolted joint using a 11C4888P01
torque wrench. 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 four commenters. The commenters were
American Airlines (American), The Boeing Company (Boeing), GE Aviation,
and United Airlines Engineering (UAL Engineering). The following
presents the comments received on the NPRM and the FAA's response to
each comment.
Request To Add Engine Serial Numbers to Applicability Paragraph
American requested that the FAA clarify paragraph (c),
Applicability, by adding the affected engine serial numbers (S/Ns).
American explained that operators do not have visibility to the engines
that were assembled or reassembled by GE with the 11C4525P01 torque
fixture, or engines that were assembled with the 11C4629P01 torque
wrench. American noted that due to this lack of visibility, operators
will need to rely on GE to provide the affected engine S/Ns, either in
GEnx-1B Service Bulletin (SB) 72-0495 R00, dated May 11, 2021 (GEnx-1B
SB 72-0495) or in response to an inquiry, which would place an
excessive burden on the operators.
The FAA disagrees with adding engine S/Ns to the Applicability
paragraph of this AD. According to GE, each maintenance, repair and
overhaul (MRO) shop will have a record of what date the new 11C4888P01
torque wrench was implemented for use, and any CDP bolted joint
reassembled at an engine shop visit prior to that implementation date
would have used the prior 11C4525P01 torque fixture. Thus, for engines
that have had an engine shop visit, each operator will be able to
determine if their engine is affected based on the date of the last
engine shop visit and the date that the particular MRO shop implemented
the new tool. For engines that have not had an engine shop visit,
Paragraph 1.A, Table A of GEnx-1B SB 72-0495 and Paragraph 1.A, Table A
of GE GEnx-2B SB 72-0433 R00, dated May 11, 2021 define which engine S/
Ns are affected based on production records.
Request To Add Clarifying Language to Required Actions
GE Aviation requested that the FAA update the language in paragraph
(g)(2) of this AD to incorporate a reference to the terminating action
contained in paragraph (h) of this AD. GE supported its request for
change by explaining the additional reference will ensure clear
understanding of the requirements.
The FAA disagrees with updating paragraph (g)(2) of this AD to
incorporate a reference to the terminating action in paragraph (h) of
this AD. Referencing paragraph (h) within paragraph (g)(2) is
unnecessary.
Request To Add Language Requiring Accomplishment of Terminating Action
UAL Engineering requested that the FAA incorporate the terminating
action in paragraph (h) of this AD as a requirement in paragraph (g)(3)
of this
[[Page 8179]]
AD. UAL Engineering explained that requiring the terminating action
within paragraph (g)(3) of this AD would eliminate any ambiguity
involving the reassembly of the CDP bolted joint, which could
potentially lead to the use of a non-conforming tool and additional
repetitive inspections.
The FAA disagrees with revising the required action as proposed by
UAL Engineering. MRO shops no longer use the 11C4525P01 torque fixture.
All MRO shops have implemented the use of the updated 11C4888P01 torque
wrench. Therefore, if a piece part inspection is required pursuant to
paragraph (g)(3) of this AD, the CDP bolted joint will be reassembled
with the updated 11C4888P01 torque wrench. The non-conforming tool will
not be used, and therefore will not drive any additional repetitive
inspections after a reassembly is performed following a piece part
inspection.
Support for the AD
Boeing 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, 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-1B SB 72-0495 R00, dated May 11, 2021 (GE
GEnx-1B SB 72-0495) and GE GEnx-2B SB 72-0433 R00, dated May 11, 2021
(GEnx-2B SB 72-0433). GEnx-1B SB 72-0495 describes procedures for the
inspection of the CDP bolted joint components on GEnx-1B model turbofan
engines. GEnx-2B SB 72-0433 describes procedures for the inspection of
the CDP bolted joint components on GEnx-2B model turbofan engines. 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 320 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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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspection of CDP bolted joint........ 1 work-hour x $85 per $0 $85 $27,200
hour = $85.
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The FAA estimates the following costs to do any necessary
additional inspections that would be required based on the results of
the proposed inspection. The agency has no way of determining the
number of aircraft that might need these inspections.
On-Condition Costs
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Cost per
Action Labor cost Parts cost product
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Piece part inspection of stages 6-10 56 work-hours x $85 per hour = $0 $4,760
compressor rotor spool. $4,760.
Piece part inspection of CPD seal............. 22 work-hours x $85 per hour = 0 1,870
$1,870.
Piece part inspection of HPT rotor stage 1 59 work-hours x $85 per hour = 0 5,015
disk. $5,015.
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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.
[[Page 8180]]
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
2022-03-16 General Electric Company: Amendment 39-21933; Docket No.
FAA-2021-0831; Project Identifier AD-2021-00712-E.
(a) Effective Date
This airworthiness directive (AD) is effective March 21, 2022.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) GEnx-1B64,
GEnx-1B64/P1, GEnx-1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/P2,
GEnx-1B70, GEnx-1B70/75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-
1B70/P2, GEnx-1B70C/P1, GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/
75/P2, GEnx-1B76/P2, GEnx-1B76A/P2, GEnx-2B67, GEnx-2B67B, and GEnx-
2B67/P model turbofan engines with a compressor discharge pressure
(CDP) bolted joint assembled or reassembled with the 11C4525P01
torque fixture or assembled with the 11C4629P01 torque wrench.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by a report from the manufacturer of two
findings of sheared CDP bolts during engine shop visits. The FAA is
issuing this AD to prevent fracture of the CDP bolt. The unsafe
condition, if not addressed, could result in damage to the engine
and damage to the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) At the next engine shop visit after the effective date of
this AD, perform an inspection of the CDP bolted joint for fractured
or missing material using the Accomplishment Instructions, paragraph
3.A.(2) of GE GEnx-1B Service Bulletin (SB) 72-0495 R00, dated May
11, 2021 (GEnx-1B SB 72-0495) (for GEnx-1B models) or Accomplishment
Instructions, paragraph 3.A.(2) of GE GEnx-2B SB 72-0433 R00, dated
May 11, 2021, (GEnx-2B SB 72-0433) (for GEnx-2B models).
(2) Repeat the inspection required by paragraph (g)(1) of this
AD at every engine shop visit.
(3) If a fractured or missing bolt or nut is found during any
inspection required by paragraph (g)(1) or (2) of this AD, before
further flight, perform piece part inspections of the stages 6-10
compressor rotor spool, CDP seal, and high-pressure turbine rotor
stage 1 disk in accordance with the Instructions for Continued
Airworthiness.
(h) Terminating Action
As terminating action to the repetitive inspections required by
paragraph (g)(2) of this AD, reassemble the CDP bolted joint using
the 11C4888P01 torque wrench, in accordance with the Accomplishment
Instructions, paragraph 3.B.(1) of GEnx-1B SB 72-0495 (for GEnx-1B
models) or the Accomplishment Instructions, paragraph 3.B.(1) of
GEnx-2B SB 72-0433 (for GEnx-2B models).
(i) Definition
For the purpose of this AD, an ``engine shop visit'' is the
induction of an engine into the shop for maintenance involving a
module exposure in which the mid fan shaft removal exposes the CDP
bolted joint.
(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
ECO Branch, send it to the attention of the person identified in
paragraph (k) of this AD. You may email your request to: <a href="/cdn-cgi/l/email-protection#87c6c9c2aac6c3aac6cac8c4c7e1e6e6a9e0e8f1"><span class="__cf_email__" data-cfemail="7938373c54383d543834363a391f1818571e160f">[email protected]</span></a>.
(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
For more information about this AD, contact Alexei Marqueen,
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue,
Burlington, MA 01803; phone: (781) 238-7178; fax: (781) 238-7199;
email: <a href="/cdn-cgi/l/email-protection#d899b4bda0bdb1f68cf695b9aaa9adbdbdb698beb9b9f6bfb7ae"><span class="__cf_email__" data-cfemail="df9eb3baa7bab6f18bf192beadaeaababab19fb9bebef1b8b0a9">[email protected]</span></a>.
(l) 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) General Electric Company (GE) GEnx-1B Service Bulletin (SB)
72-0495 R00, dated May 11, 2021.
(ii) GE GEnx-2B SB 72-0433 R00, dated May 11, 2021.
(3) For GE service information identified in this AD, contact
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215;
phone: (513) 552-3272; email: <a href="/cdn-cgi/l/email-protection#d9b8afb0b8adb0b6b7f7bfb5bcbcadaaaca9a9b6abad99b8bcf7bebcf7bab6b4"><span class="__cf_email__" data-cfemail="caabbca3abbea3a5a4e4aca6afafbeb9bfbabaa5b8be8aabafe4adafe4a9a5a7">[email protected]</span></a>;
website: <a href="http://www.ge.com">www.ge.com</a>.
(4) You may view this service information at 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 (817) 222-5110.
(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#7117035f181f0201141205181e1f311f1003105f161e07"><span class="__cf_email__" data-cfemail="a0c6d28ec9ced3d0c5c3d4c9cfcee0cec1d2c18ec7cfd6">[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 January 25, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2022-03040 Filed 2-11-22; 8:45 am]
BILLING CODE 4910-13-P
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