Document ID: FAA-2021-1069-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Engine Alliance Turbofan Engines
Posted Date: 2021-12-28T05:00Z

[Federal Register Volume 86, Number 246 (Tuesday, December 28, 2021)]
[Rules and Regulations]
[Pages 73667-73670]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-27981]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1069; Project Identifier AD-2021-00308-E; 
Amendment 39-21862; AD 2021-26-04]
RIN 2120-AA64

Airworthiness Directives; Engine Alliance Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2019-18-08 
which applied to all Engine Alliance (EA) GP7270 and GP7277 model 
turbofan engines. AD 2019-18-08 required a visual inspection of the 
engine fan hub assembly, initial and repetitive eddy current 
inspections (ECIs) of the engine fan hub blade slot bottom and blade 
slot front edge for cracks, and replacement of the engine fan hub blade 
lock assembly for certain affected engines. This AD continues to 
require initial and repetitive ECIs and adds an ultrasonic test (UT) 
inspection. This AD also lowers the repetitive ECI threshold, and 
requires an independent inspection of the engine fan hub assembly at 
the next disassembly and the next reassembly of the engine fan hub 
blade lock assembly and a visual inspection of the engine fan hub 
assembly for damage. This AD also requires replacement of the engine 
fan hub assembly with a part eligible for installation if damage is 
found outside serviceable limits. This AD was prompted by an 
uncontained failure of the engine fan hub. The FAA is issuing this AD 
to address the unsafe condition on these products.

DATES: This AD is effective January 12, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of January 12, 
2022.
    The FAA must receive any comments on this AD by February 11, 2022.

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 final rule, contact 
Engine Alliance, 411 Silver Lane, East Hartford, CT 06118; phone: (800) 
565-0140; email: [email protected]; website: 
www.engineallianceportal.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 (817) 222-5110. It is 
also available at https://www.regulations.gov by searching for and 
locating Docket No. FAA-2021-1069.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-1069; 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 Docket 
Operations is listed above.

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

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued AD 2019-18-08, Amendment 39-19735 (84 FR 49944, 
September 24, 2019), (AD 2019-18-08), for all EA GP7270 and GP7277 
model turbofan engines. AD 2019-18-08 required, for certain GP7270 and 
GP7277 model turbofan engines, an initial and repetitive ECI of the 
engine fan hub blade slot bottom and blade slot front edge for cracks. 
For all GP7270 and GP7277 model turbofan engines, AD 2019-18-08 also 
required an independent inspection of the engine fan hub assembly prior 
to the reassembly of the engine fan hub blade lock assembly and a 
visual inspection of the engine fan hub assembly for damage. For 
certain serial numbered GP7270 and GP7277 model turbofan engines, AD 
2019-18-08 required replacement of the engine fan hub blade lock 
assembly with a part eligible for installation. AD 2019-18-08 resulted 
from the manufacturer identifying a fatigue crack originating inboard 
of a blade slot after the manufacturer performed a metallurgical 
examination of the engine fan hub that was recovered, related to an 
uncontained engine hub failure that occurred on September 30, 2017. 
After performing a risk assessment, the manufacturer determined the 
need to reduce the compliance time for the initial ECI and add a 
repetitive ECI. The FAA issued AD 2019-18-08 to detect defects, damage, 
and cracks that could result in an uncontained failure of the engine 
fan hub assembly.

Actions Since AD 2019-18-08 Was Issued

    Since the FAA issued AD 2019-18-08, EA has revised its Alert 
Service Bulletin, reducing the repetitive ECI interval from 330 cycles 
to 290 cycles, and adding an inner diameter UT inspection of the rim 
area for cracks. EA published EA Turbojet Engine Alert Service Bulletin 
(ASB) No. EAGP7-A72-389, Revision No. 7, dated October 8, 2021, to 
update the repetitive inspection interval for performing the ECIs and 
add UT inspections. The FAA

[[Page 73668]]

is issuing this AD to address the unsafe condition on these products.

FAA's Determination

    The FAA is issuing this AD because the agency determined the unsafe 
condition described previously is likely to exist or develop in other 
products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed EA Turbojet Engine ASB No. EAGP7-A72-389, Revision 
No. 7, dated October 8, 2021. This ASB describes procedures for 
performing an ECI of the engine fan hub blade slot bottom and blade 
slot front edge, and performing a UT inspection of the fan hub rim area 
for engine fan hub assemblies at the LPC module assembly level, at the 
piece part level, and installed in an engine (on-wing or off-wing). 
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.

Other Related Service Information

    The FAA reviewed EA Turbojet Engine ASB No. EAGP7-A72-418, Revision 
No. 1, dated January 11, 2019. This ASB provides guidance on 
replacement or modification of the engine fan hub blade lock assembly.
    The FAA also reviewed the following service information:
    Subtask 72-31-42-210-001-A, of Task 72-31-42-000-802-A, from the 
A380 Aircraft Maintenance Manual (AMM). This subtask describes 
procedures for performing an on-wing visual inspection after removal of 
the engine fan hub blade lock assembly.
    Figure 405 of Task 72-00-31-420-004 of the EA GP7000 Series Engine 
Manual (EM). This figure and task describe procedures for performing a 
visual inspection after removal of the engine fan hub blade lock 
assembly when the engine is in the shop.
    Subtask 72-00-00-210-012-A, of Task 72-00-00-210-806-A, from the 
A380 AMM. This subtask describes procedures for performing an on-wing 
visual inspection after reassembly of the engine fan hub blade lock 
assembly.
    Task 72-00-31-420-004, Paragraph 1.E.(13), of the EA GP7000 Series 
EM. This task describes procedures for performing a visual inspection 
after reassembly of the engine fan hub blade lock assembly when the 
engine is in the shop.
    Table 601 in Subtask 72-00-00-210-012-A of Task 72-00-00-210-806, 
from the A380 AMM, and Task 72-00-31-220-010 of the EA GP7000 Series 
EM. Table 601 and Task 72-00-31-220-010 describe acceptable damage 
service limits for the engine fan hub assembly.

AD Requirements

    This AD requires, for GP7270 and GP7277 model turbofan engines with 
engine fan hub assembly part numbers (P/Ns) 5760221, 5760321, or 
5760001, initial and repetitive ECI of the engine fan hub blade slot 
bottom and blade slot front edge for cracks. Additionally, this AD 
lowers the repetitive ECI threshold, in conjunction with the added 
repetitive UT inspection threshold. This AD also requires initial and 
repetitive UT inspections of the fan hub rim area. This AD also 
requires an independent inspection of the engine fan hub assembly at 
the next disassembly and the next reassembly of the engine fan hub 
blade lock assembly and a visual inspection of the engine fan hub 
assembly for damage. This AD also requires replacement of the engine 
fan hub assembly with a part eligible for installation if damage is 
found outside serviceable limits.
    For certain serial-numbered GP7270 and GP7277 model turbofan 
engines, this AD requires replacement of the engine fan hub blade lock 
assembly with a part eligible for installation.

Interim Action

    The FAA considers this AD to be an interim action. If final action 
is later identified, the FAA might consider further rulemaking.

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. 551 et seq.) 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 providing notice and seeking 
comment prior to issuance. Further, section 553(d) of the APA 
authorizes agencies to make rules effective in less than thirty 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 any U.S. 
operator. Accordingly, notice and opportunity for prior public comment 
are unnecessary, pursuant to 5 U.S.C. 553(b)(3)(B). In addition, for 
the foregoing reason(s), the FAA finds that good cause exists pursuant 
to 5 U.S.C. 553(d) for making this amendment effective in less than 30 
days.

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments to an address listed under 
ADDRESSES. Include ``Docket No. FAA-2021-1069 and Project Identifier 
AD-2021-00308-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 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 agency will also post a report summarizing each 
substantive verbal contact received about this final rule.

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, 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.

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 FAA has determined 
that it has good cause to

[[Page 73669]]

adopt this rule without prior 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
----------------------------------------------------------------------------------------------------------------
Perform ECI...........................  20 work-hours x $85 per               $0          $1,700              $0
                                         hour = $1,700.
Perform UT Inspection.................  7 work-hours x $85 per                 0             595               0
                                         hour = $595.
Perform Visual Inspection.............  1 work-hour x $85 per                  0              85               0
                                         hour = $85.
Replace fan hub blade lock assembly...  25 work-hours x $85 per           28,000          30,125               0
                                         hour = $2,125.
----------------------------------------------------------------------------------------------------------------

    FAA estimates the following costs to do any necessary replacements 
that would be required based on the results of the inspection. The 
agency has no way of determining the number of aircraft that might need 
these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace engine fan hub assembly...............  50 work-hours x $85 per hour =          $790,500        $794,750
                                                 $4,250.
----------------------------------------------------------------------------------------------------------------

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.

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:
0
a. Removing Airworthiness Directive 2019-18-08, Amendment 39-19735 (84 
FR 49944, September 24, 2019); and
0
b. Adding the following new airworthiness directive:

2021-26-04 Engine Alliance: Amendment 39-21862; Docket No. FAA-2021-
1069; Project Identifier AD-2021-00308-E.

(a) Effective Date

    This airworthiness directive (AD) is effective January 12, 2022.

(b) Affected ADs

    This AD replaces AD 2019-18-08, Amendment 39-19735 (84 FR 49944, 
September 24, 2019).

(c) Applicability

    This AD applies to all Engine Alliance (EA) GP7270 and GP7277 
model turbofan engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by an uncontained failure of the engine fan 
hub. The FAA is issuing this AD to detect defects, damage, and 
cracks that could result in an uncontained failure of the engine fan 
hub assembly. The unsafe condition, if not addressed, could result 
in uncontained failure of the engine fan hub assembly, 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) For EA GP7270 and GP7277 model turbofan engines with engine 
fan hub assembly part numbers (P/Ns) 5760221, 5760321, or 5760001, 
within 1,700 cycles since new, within 150 flight cycles (FCs) after 
October 9, 2019 (the effective date of AD 2019-18-08), within 330 
FCs since an eddy current inspection (ECI) was performed using the 
Accomplishment Instructions of EA Turbojet Engines Alert Service 
Bulletin (ASB) EAGP7-A72-389, Revision No. 6, dated November 21, 
2019, or earlier versions of that ASB, or before further flight, 
whichever occurs later:
    (i) For engine fan hub assemblies at the low-pressure compressor 
(LPC) module assembly level, perform an ECI of the engine fan hub 
blade slot bottom and blade slot front edge, and perform an 
ultrasonic test (UT)

[[Page 73670]]

inspection of the fan hub rim area, using the Accomplishment 
Instructions, Part A--For Fan Hubs at LPC Module Assembly Level, 
paragraphs 1.B., 1.C., and 1.E., of EA Turbojet Engine ASB EAGP7-
A72-389, Revision No. 7, dated October 8, 2021 (EAGP7-A72-389, 
Revision No. 7).
    (ii) For engine fan hub assemblies at the piece part level, 
perform an ECI of the engine fan hub blade slot bottom and blade 
slot front edge, and perform a UT inspection of the fan hub rim 
area, using the Accomplishment Instructions, Part B--For Fan Hubs at 
Piece Part Level, paragraphs 1.B., 1.C., and 1.E., of EAGP7-A72-389, 
Revision No. 7.
    (iii) For engine fan hub assemblies installed in an engine (on-
wing or off-wing), perform an ECI of the engine fan hub blade slot 
bottom and blade slot front edge, and perform a UT inspection of the 
fan hub rim area, using the Accomplishment Instructions, Part C--For 
Fan Hubs Installed in an Engine, paragraphs 3.B., 3.C., and 3.E., of 
EAGP7-A72-389, Revision No. 7.
    (2) Thereafter, at intervals not exceeding 290 FCs since the 
previous ECI and UT inspection, repeat the ECI of the engine fan hub 
blade slot bottom, ECI of the blade slot front edge, and UT 
inspection of the fan hub rim area required by paragraphs (g)(1)(i) 
through (iii) of this AD.
    (3) If, during any ECI or UT inspection required by paragraphs 
(g)(1) through (g)(2) of this AD, a rejectable indication is found, 
before further flight, remove the engine fan hub assembly from 
service and replace with a part that is eligible for installation.
    (4) For all GP7270 and GP7277 model turbofan engines, after the 
effective date of this AD:
    (i) At the next disassembly of the engine fan hub blade lock 
assembly, visually inspect the fan hub fan blade lock groove area 
(also known as the fan hub lock ring contact area) for damage.
    (ii) At the next reassembly of the engine fan hub blade lock 
assembly, visually inspect the following areas of the engine fan hub 
for damage:
    (A) The fan hub scallop areas;
    (B) The fan hub bore area behind the balance flange;
    (C) The fan hub fan blade lock retention hooks;
    (D) The fan hub rim face; and
    (E) The clinch nut holes.
    (iii) After any reassembly of the fan hub blade lock assembly, 
before further flight, perform an independent inspection for damage 
of the areas of the engine fan hub identified in paragraph 
(g)(4)(ii) of this AD.
    (iv) Thereafter, repeat the inspections required by paragraphs 
(g)(4)(i) through (iii) of this AD at each disassembly and 
reassembly of the engine fan hub blade lock assembly, as applicable.
    (v) As an optional terminating action to the inspection and 
independent inspection requirements of paragraphs (g)(4)(i) through 
(iv) of this AD, insert the requirements for the visual inspections 
and independent inspections required by paragraphs (g)(4)(i) through 
(iv) as Required Inspection Items in the existing approved 
continuous airworthiness maintenance program for the airplane.
    (vi) If damage is found that exceeds serviceable limits during 
the inspections required by paragraphs (g)(4)(i) through (iv) of 
this AD, before further flight, remove the engine fan hub assembly 
from service and replace it with a part eligible for installation.
    (5) For GP7270 and GP7277 model turbofan engines with engine 
serial numbers P550101 through P550706, inclusive, within 200 FCs 
from August 1, 2020 or before further flight, whichever occurs 
later, remove the engine fan hub blade lock assembly, P/N 5700451, 
and replace it with a part eligible for installation.
    Note 1 to paragraph (g)(5): EA Turbojet Engines ASB EAGP7-A72-
418, Revision No. 1, dated January 11, 2019, contains guidance on 
replacement of the engine fan hub blade lock assembly.

(h) Credit for Previous Actions

    You may take credit for the ECI inspections required by 
paragraph (g)(1)(i) through (iii) of this AD if you performed the 
ECI inspections before the effective date of this AD using EA ASB 
EAGP7-A72-389, Revision No. 6, dated November 21, 2019, or an 
earlier version.

(i) Definitions

    (1) For the purpose of this AD, a ``part eligible for 
installation,'' when referring to replacement of the engine fan hub 
assembly, is a part that has passed the inspections required by 
paragraph (g)(1) of this AD.
    (2) For the purpose of this AD, a ``part eligible for 
installation,'' when referring to replacement of the engine fan hub 
blade lock assembly, is:
    (i) A part that is not P/N 5700451, or
    (ii) An engine fan hub blade lock assembly that has been 
modified in accordance with EA ASB EAGP7-A72-418, Revision No. 1, 
dated January 11, 2019, or EA ASB EAGP7-A72-418, Revision No. 0, 
dated December 7, 2018.
    (3) For the purpose of this AD, an ``independent inspection'' is 
a second visual inspection performed by an individual qualified to 
perform inspections who was not involved in the original inspection 
of the engine fan hub assembly following disassembly and reassembly 
of the engine fan hub blade lock assembly.

(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. Information may be emailed 
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, 
Aviation Safety 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) Engine Alliance (EA) Turbojet Engines Alert Service Bulletin 
EAGP7-A72-389, Revision No. 7, dated October 8, 2021.
    (ii) [Reserved]
    (3) For EA service information identified in this AD, contact 
Engine Alliance, 411 Silver Lane, East Hartford, CT, 06118; phone: 
(800) 565-0140; email: [email protected]; website: 
www.engineallianceportal.com.
    (4) 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.
    (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: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on December 8, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-27981 Filed 12-27-21; 8:45 am]
BILLING CODE 4910-13-P