Airworthiness Directives; General Electric Company Turbofan Engines

[Federal Register Volume 85, Number 92 (Tuesday, May 12, 2020)]
[Rules and Regulations]
[Pages 27909-27911]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-10048]



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Federal Register / Vol. 85, No. 92 / Tuesday, May 12, 2020 / Rules 
and Regulations

[[Page 27909]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0469; Project Identifier AD-2020-00258-E; 
Amendment 39-21122; AD 2020-10-04]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
General Electric Company (GE) GE90-110B1 and GE90-115B model turbofan 
engines with a certain interstage high-pressure turbine (HPT) rotor 
seal installed. This AD requires initial and repetitive ultrasonic 
inspections (USIs) of the interstage HPT rotor seal and, depending on 
the results of the inspection, replacement of the interstage HPT rotor 
seal with a part eligible for installation. This AD also requires the 
removal of the interstage HPT rotor seal at the next engine shop visit. 
This AD was prompted by investigative findings from an event involving 
an uncontained interstage HPT rotor seal failure that resulted in 
debris penetrating the fuselage and the other engine. The FAA is 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective May 27, 2020.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 27, 
2020.
    The FAA must receive comments on this AD by June 26, 2020.

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 https://www.regulations.gov. 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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    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; email: 
[email protected]. 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 on the internet at https://www.regulations.gov by searching 
for and locating Docket No. FAA-2020-0469.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0469; 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 the Docket Operations is listed above. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Stephen Elwin, Aerospace Engineer, ECO 
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7236; fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA received a report of an event that occurred on October 20, 
2019, in which a Boeing Model 777-300ER airplane, powered by GE GE90-
115B model turbofan engines, experienced an uncontained interstage HPT 
rotor seal failure resulting in an aborted takeoff. The FAA has 
determined that an unusual flight profile is a contributing factor in 
the failure of the interstage HPT rotor seal. This condition, if not 
addressed, could result in an uncontained interstage HPT rotor seal 
release, release of high-energy debris, damage to the engine, and 
damage to the airplane. The FAA is issuing this AD to address the 
unsafe condition on these products.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed GE GE90-100 Alert Service Bulletin (ASB) 72-A0841 
R00, dated February 26, 2020. The ASB describes procedures for 
performing USIs of the interstage HPT rotor seal and removing it from 
service. 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.

Other Related Service Information

    The FAA reviewed GE GE90-100 Service Bulletin (SB) 72-0830 R00, 
dated January 17, 2020. The SB describes procedures for performing a 
USI at the air holes of the interstage HPT rotor seal on wing.

FAA's Determination

    The FAA is issuing this AD because the Agency evaluated all the 
relevant information and determined the unsafe condition described 
previously is likely to exist or develop in other products of the same 
type design.

AD Requirements

    This AD requires initial and repetitive USIs of the interstage HPT 
rotor seal and, depending on the results of the inspection, replacement 
of the interstage HPT rotor seal with a part eligible for installation. 
This AD also requires the removal of the interstage HPT rotor seal at 
the next engine shop visit.

Interim Action

    The FAA considers this AD interim action. The root cause of the 
interstage HPT rotor seal failure is still being investigated, and the 
FAA will consider further rulemaking depending on the results of the 
investigation.

[[Page 27910]]

Justification for Immediate Adoption and Determination of the Effective 
Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 
U.S.C.) authorizes agencies to dispense with notice and comment 
procedures 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 seeking comment prior to the 
rulemaking. Similarly, Section 553(d) of the APA authorizes agencies to 
make rules effective in less than 30 days, upon a finding of good 
cause.
    The FAA has found the risk to the flying public justifies waiving 
notice and comment prior to adoption of this rule because no domestic 
operators use this product. It is unlikely that the FAA will receive 
any adverse comments or useful information about this AD from U.S. 
operators. Therefore, the FAA finds good cause that notice and 
opportunity for prior public comment are unnecessary. In addition, for 
this same reason, the FAA finds that good cause exists for making this 
amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, 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 the docket number FAA-2020-
0469 and Project Identifier AD-2020-00258-E at the beginning of your 
comments. The FAA specifically invites comments on the overall 
regulatory, economic, environmental, and energy aspects of this final 
rule. 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 
https://www.regulations.gov, including any personal information you 
provide. The FAA will also post a report summarizing each substantive 
verbal contact received about this final rule.

Confidential Business Information

    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 Stephen Elwin, Aerospace 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.

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 0 engines installed on 
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Replace interstage HPT rotor seal.....  100 work-hours x $85 per        $540,000        $548,500              $0
                                         hour = $8,500.
USI of interstage HPT rotor seal......  2 work-hours x $85 per                 0             170               0
                                         hour = $170.
----------------------------------------------------------------------------------------------------------------

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.

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.

[[Page 27911]]

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2020-10-04 General Electric Company: Amendment 39-21122; Docket No. 
FAA-2020-0469; Project Identifier AD-2020-00258-E.

(a) Effective Date

    This AD is effective May 27, 2020.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all General Electric Company (GE) GE90-110B1 
and GE90-115B model turbofan engines with an interstage high-
pressure turbine (HPT) rotor seal with a part number and serial 
number listed in Table 1 of GE GE90-100 Alert Service Bulletin (ASB) 
72-A0841 R00, dated February 26, 2020 (``the ASB'').

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by investigative findings from an event 
involving an uncontained interstage HPT rotor seal failure, 
resulting in debris penetrating the fuselage and the other engine. 
The FAA is issuing this AD to prevent failure of the interstage HPT 
rotor seal. The unsafe condition, if not addressed, could result in 
uncontained interstage HPT rotor seal release, release of high-
energy debris, 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) Perform an ultrasonic inspection (USI) of the interstage HPT 
rotor seal in accordance with the Accomplishment Instructions, 
paragraph 3.B.(1), of the ASB, as follows:
    (i) After the effective date of this AD, perform an initial USI 
of the interstage HPT rotor seal before reaching the additional 
cycles listed in Table 1 of the ASB. When computing the additional 
cycles, use the effective date of this AD instead of the issue date 
of the ASB.
    (ii) Thereafter, repeat the USI of the interstage HPT rotor seal 
required by paragraph (g)(1)(i) within every 100 cycles since the 
last inspection.
    (2) If, during any USI required by paragraph (g)(1)(i) or (ii) 
of this AD, a non-serviceable indication is found, as defined in 
paragraph 3.B.(2)(b) of the ASB, before further flight, remove the 
interstage HPT rotor seal from service.

(h) Mandatory Terminating Action

    As a terminating action to the repetitive USI required by 
paragraph (g)(1)(ii) of this AD, at the next engine shop visit after 
the effective date of this AD, remove the affected interstage HPT 
rotor seal from service and replace with a part eligible for 
installation.

(i) Definition

    For the purpose of this AD, an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine case flanges, except 
separation of engine flanges solely for the purposes of 
transportation of the engine without subsequent maintenance does not 
constitute an engine shop visit.

(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 paragraph (k) 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.

(k) Related Information

    For more information about this AD, contact Stephen Elwin, 
Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: 781-238-7236; fax: 781-238-7199; email: 
[email protected].

(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) GE90-100 Alert Service 
Bulletin 72-A0841 R00, dated February 26, 2020.
    (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; email: 
[email protected].
    (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 781-238-7759.
    (5) You may view this service information at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, email: [email protected], 
or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on May 6, 2020.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2020-10048 Filed 5-11-20; 8:45 am]
 BILLING CODE 4910-13-P

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