Airworthiness Directives; General Electric Company Turbofan Engines

[Federal Register Volume 82, Number 242 (Tuesday, December 19, 2017)]
[Rules and Regulations]
[Pages 60106-60108]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-27248]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0660; Product Identifier 2017-NE-21-AD; Amendment 
39-19132; AD 2017-26-01]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
General Electric Company (GE) GEnx-1B64/P2, -1B67/P2, -1B70/P2, -1B70/
75/P2, -1B70C/P2, and -1B74/75/P2 turbofan engines. This AD was 
prompted by a report of the failure of the high-pressure turbine (HPT) 
stage 1 blade retainer and subsequent in-flight shutdown of the engine. 
This AD requires inspection of the HPT stage 1 blade retainer. We are 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective January 23, 2018.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 23, 
2018.

ADDRESSES: For service information identified in this final rule, 
contact General Electric Company, GE-Aviation, Room 285, 1 Neumann Way, 
Cincinnati, OH 45215, phone: 513-552-3272; fax: 513-552-3329; email: 
[email protected]. You may view this service information at the FAA, 
Engine and Propeller Standards Branch, 1200 District Avenue, 
Burlington, MA. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-
0660.

Examining the AD Docket

    You may examine the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-
0660; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this final rule, the regulatory evaluation, any comments 
received, and other information. The address for the Docket Office 
(phone: 800-647-5527) is Document Management Facility, 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: Christopher McGuire, Aerospace 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7120; fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to certain GE GEnx-1B64/P2, -
1B67/P2, -1B70/P2, -1B70/75/P2, -1B70C/P2, and -1B74/75/P2 turbofan 
engines. The NPRM published in the Federal Register on September 1, 
2017 (82 FR 41577). The NPRM was prompted by a report of the failure of 
the HPT stage 1 blade retainer and subsequent in-flight shutdown of the 
engine. The NPRM proposed to require inspection of the HPT stage 1 
blade retainer. We are issuing this AD to correct the unsafe condition 
on these products.

Comments

    We gave the public the opportunity to participate in developing 
this final rule. The following presents the comments received on the 
NPRM and the FAA's response to each comment.

Request To Revise Compliance Time

    American Airlines (AA) requested that we change the compliance time 
in this AD to align with the compliance schedule in GE GEnx-1B Service 
Bulletin (SB) 72-0326 R02, revised August 16, 2017. AA indicated the SB 
identifies two populations of HPT stage 1 blade retainers, one that 
requires inspection at the next shop visit and a second that requires 
inspection when the part is removed from the engine. The proposed AD, 
however, proposed inspection of all affected retainers at next shop 
visit. Due to this discrepancy between the proposed AD and the SB, AA 
requested this AD require inspections of the HPT stage 1 blade 
retainers at next shop visit and at part removal, as required by GEnx-
1B SB 72-0326 R02.
    GE commented that, based on its analysis, conducting the required 
inspection of the HPT stage 1 blade retainer at its next piece-part 
exposure is sufficient. GE requested that this final rule AD be changed 
to require inspection of all affected parts at piece-part exposure 
rather than at the next shop visit.
    We partially agree. We disagree with AA that requiring inspections 
of HPT stage 1 blade retainers at next shop visit and at part removal, 
per GE GEnx-1B SB 72-0326 R02, revised August 16, 2017, is necessary. 
We agree with GE that the risk assessment justifies waiting until 
exposure of the part to perform the inspection and the change clarifies 
the compliance action. We revised the compliance section of this AD to 
require that the HPT stage 1 blade retainer be inspected at its next 
piece-part exposure.

Request To Align Compliance by Part Population

    Japan Airlines (JAL) requested that the compliance be changed to 
two populations of parts with two different compliance intervals. JAL 
indicated this change would align this AD with the two populations of 
affected parts identified in GE GEnx-1B SB 72-0326 R02, revised August 
16, 2017.
    We disagree. Although the SB specifies certain part numbers be 
inspected sooner than at piece-part exposure, our risk assessment 
determined that performing the inspection for all affected parts at 
piece-part exposure addresses the safety concern represented by failure 
of the HPT stage 1 blade retainer. We did not change this AD.

Request To Incorporate Required for Compliance (RC) Label Into SB

    AA requested that we incorporate the RC label into GEnx-1B SB 72-
0326 R02, revised August 16, 2017. AA indicated this change would 
clarify which sections of the SB are required to accomplish this AD. 
Using the RC label in the SB would also be consistent with FAA Advisory 
Circular (AC) 20-176A, ``Service Bulletins Related to Airworthiness 
Directives and Indicating FAA Approval on Service Documents,'' dated 
June 16, 2014, and FAA Order 8110.117A, ``Service Bulletins Related to 
Airworthiness Directives,'' dated June 18, 2014.
    We disagree. FAA Order 8110.117A and AC 20-176A provide guidance, 
respectively, to FAA aviation safety engineers in the review of SBs and 
to design approval holders (DAHs) in the development and drafting of 
these SBs. These documents do not require use of the RC label by DAHs 
in drafting in SBs, and GE is not required to use this label. The 
paragraph from GE GEnx-1B SB 72-0326 R02, revised August 16, 2017,

[[Page 60107]]

that is incorporated by reference by this AD, clearly identifies the 
steps that operators must follow to perform the inspection. We did not 
change this AD.

Request To Add Reference to Related SB

    An individual commenter requested that GE GEnx-1B SB 72-0327 R02, 
revised August 16, 2017, be mentioned in this AD since this SB is 
related to GEnx-1B SB 72-0326 R02, revised August 16, 2017. The 
commenter indicated GEnx-1B SB 72-0327 also relates to inspection of 
the stage one HPT blade retainer, but references an alternate part 
number. The commenter requested that the relationship between GEnx-1B 
SB 72-0327 R02 and GEnx-1B SB 72-0326 R02 be stated clearly.
    We partially agree. Although GE GEnx-1B SB 72-0327 R02, revised 
August 16, 2017, has a part number in common with the parts identified 
in GE GEnx-1B SB 72-0326 R02, revised August 16, 2017, the serial 
numbers for the parts identified in GEnx-1B SB 72-0327 differ from 
those in GEnx-1B SB 72-0326. The serial numbered parts identified in 
GEnx-1B SB 72-0327 pose a lower risk to flight safety and are not 
affected by this AD. We did not change this AD.

Support for the AD

    The Air Line Pilots Association expressed support for the NPRM as 
written.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this final rule with the changes described previously and minor 
editorial changes. We have determined that these minor changes:
    <bullet> [Agr]re consistent with the intent that was proposed in 
the NPRM for correcting the unsafe condition; and
    <bullet> Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this final 
rule.

Related Service Information Under 1 CFR Part 51

    We reviewed GE GEnx-1B SB 72-0326 R02, revised August 16, 2017. The 
SB describes procedures for piece-part inspection of the HPT stage 1 
blade retainer. 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.

Costs of Compliance

    We estimate that this AD affects 11 engines installed on airplanes 
of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspection of the HPT stage 1 blade     1 work-hour x $85 per                 $0             $85            $935
 retainer.                               hour = $85.
----------------------------------------------------------------------------------------------------------------

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.
    We are 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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to engines, propellers, and 
associated appliances to the Manager, Engine and Propeller Standards 
Branch, Policy and Innovation Division.

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) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

Adoption of 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 (AD):

2017-26-01 General Electric Company: Amendment 39-19132; Docket No. 
FAA-2017-0660; Product Identifier 2017-NE-21-AD.

(a) Effective Date

    This AD is effective January 23, 2018.

(b) Affected ADs

    None.

[[Page 60108]]

(c) Applicability

    This AD applies to General Electric Company (GE) GEnx-1B64/P2, -
1B67/P2, -1B70/P2, -1B70/75/P2, -1B70C/P2, and -1B74/75/P2 turbofan 
engines, with a high-pressure turbine (HPT) stage 1 blade retainer, 
part number (P/N) 2445M91P01 or 2383M99P02, with a serial number 
listed in Planning Information, Paragraph 1.A., of GE GEnx-1B 
Service Bulletin (SB) 72-0326 R02, revised August 16, 2017.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7250, Turbine 
Section.

(e) Unsafe Condition

    This AD was prompted by a report of the failure of the HPT stage 
1 blade retainer and subsequent in-flight shutdown of the engine. We 
are issuing this AD to prevent failure of the HPT stage 1 blade 
retainer. The unsafe condition, if not corrected, could result in 
failure of one or more engines, loss of thrust control, 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 piece-part exposure of the HPT stage 1 blade 
retainer after the effective date of this AD, perform a one-time 
inspection of the HPT stage 1 blade retainer in accordance with the 
Accomplishment Instructions, paragraph 3.A.(1), in GE GEnx-1B SB 72-
0326 R02, revised August 16, 2017.
    (2) If any cracks are found in the HPT stage 1 blade retainer, 
or the retainer does not meet the dimensional criteria found in the 
Accomplishment Instructions, Paragraph 3.A.(1), in GEnx-1B SB 72-
0326 R02, revised August 16, 2017, replace the HPT stage 1 blade 
retainer with a part eligible for installation.

(h) Definition

    For the purpose of this AD, ``piece-part exposure'' is defined 
as when the part is completely disassembled.

(i) 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 (j)(1) of this AD. 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.

(j) Related Information

    For more information about this AD, contact Christopher McGuire, 
Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: 781-238-7120; fax: 781-238-7199; email: 
[email protected].

(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) General Electric Company (GE) GEnx-1B Service Bulletin 72-
0326 R02, revised August 16, 2017.
    (ii) Reserved.
    (3) For GE service information identified in this AD, contact 
General Electric Company, GE-Aviation, Room 285, 1 Neumann Way, 
Cincinnati, OH 45215, phone: 513-552-3272; fax: 513-552-3329; email: 
[email protected].
    (4) You may view this service information at FAA, Engine and 
Propeller Standards Branch, 1200 District Avenue, Burlington, MA. 
For information on the availability of this material at the FAA, 
call 781-238-7125.
    (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, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on December 11, 2017.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2017-27248 Filed 12-18-17; 8:45 am]
 BILLING CODE 4910-13-P

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