Document ID: FAA-2020-0494-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: General Electric Company Turbofan Engines
Posted Date: 2020-05-18T04:00Z

[Federal Register Volume 85, Number 96 (Monday, May 18, 2020)]
[Proposed Rules]
[Pages 29676-29678]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-10571]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0494; Project Identifier AD-2020-00324-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 all General Electric Company (GE) GE90-110B1 and GE90-115B model 
turbofan engines with a certain high-pressure turbine (HPT) rotor stage 
2 disk installed. This proposed AD was prompted by a report from the 
manufacturer that a subsurface anomaly was found on a HPT rotor stage 2 
disk. This proposed AD would require an ultrasonic inspection (USI) of 
the HPT rotor stage 2 disk and, depending on the result of the 
inspection, replacement of the HPT rotor stage 2 disk 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 July 2, 
2020.

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, GE Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 
45215; phone: 513-552-3272; email: aviation.fleetsupport@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 on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0494; 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. 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: stephen.l.elwin@faa.gov.

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 the ADDRESSES section. Include ``Docket No. FAA-2020-0494; 
Project Identifier AD-2020-00324-E'' at the beginning of your comments. 
The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of this NPRM. The FAA will 
consider all comments received by the closing date and may amend this 
NPRM 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 NPRM.

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.

Discussion

    The FAA received a report from the manufacturer that a subsurface 
anomaly was found on a HPT rotor stage 2 disk. The manufacturer 
determined that the subsurface anomaly developed during the material 
melting process. This condition, if not addressed, could result in 
uncontained HPT rotor stage 2 disk release, damage to the engine, and 
damage to the airplane.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed GE GE90-100 Service Bulletin (SB) 72-0838, dated 
January 31, 2020. The SB describes procedures for performing an USI of 
the HPT rotor stage 2 disk. 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.

FAA's Determination

    The FAA is proposing this AD because it 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.

Proposed AD Requirements

    This proposed AD would require an USI of the HPT rotor stage 2 disk 
and, depending on the results of the inspection, replacement of the HPT 
rotor stage 2 disk with a part eligible for installation.

Costs of Compliance

    The FAA estimates that this proposed AD affects 12 engines 
installed on airplanes of U.S. registry.

[[Page 29677]]

    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
----------------------------------------------------------------------------------------------------------------
USI of HPT rotor stage 2 disk.......  8 work-hours x $85 per               $0             $680          $8,160.
                                       hour = $680.
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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 
engines that might need this replacement:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Remove and replace HPT rotor stage 2 disk.....  2 work-hours x $85 per hour =           $565,600       $565,770.
                                                 $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

    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) 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 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 (AD):

General Electric Company: Docket No. FAA-2020-0494; Project 
Identifier AD-2020-00324-E.

(a) Comments Due Date

    The FAA must receive comments by July 2, 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 a high-pressure turbine 
(HPT) rotor stage 2 disk, part number 2505M73P03, and with a serial 
number listed in Appendix--A, Table 1, of GE GE90-100 Service 
Bulletin (SB) 72-0838, dated January 31, 2020.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report from the manufacturer that a 
subsurface anomaly was found on a HPT rotor stage 2 disk. The FAA is 
issuing this AD to prevent failure of the HPT rotor stage 2 disk. 
The unsafe condition, if not addressed, could result in uncontained 
HPT rotor stage 2 disk release, 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 Action

    (1) At the next piece-part exposure after the effective date of 
this AD, perform an ultrasonic inspection (USI) of the HPT rotor 
stage 2 disk in accordance with the Accomplishment Instructions, 
paragraph 3.B.(1)(a), of GE GE90-100 SB 72-0838, dated January 31, 
2020.
    (2) If, during the USI required by paragraph (g)(1) of this AD, 
a rejectable indication is found, remove the HPT rotor stage 2 disk 
from service before further flight and replace it with a part 
eligible for installation.

(h) Definition

    For the purpose of this AD, ``piece-part exposure'' is when the 
HPT rotor stage 2 disk is removed from the engine and 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 
certification office, send it to the attention of the person 
identified in paragraph (j)(1) of this AD. You may email your 
request to: ANE-AD-AMOC@faa.gov.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector,

[[Page 29678]]

or lacking a principal inspector, the manager of the local flight 
standards district office/certificate holding district office.

(j) Related Information

    (1) 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: stephen.l.elwin@faa.gov.
    (2) For 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: 
aviation.fleetsupport@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 May 13, 2020.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2020-10571 Filed 5-15-20; 8:45 am]
 BILLING CODE 4910-13-P