[Federal Register Volume 86, Number 206 (Thursday, October 28, 2021)]
[Proposed Rules]
[Pages 59658-59662]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-23180]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0835; Project Identifier AD-2021-00971-E]
RIN 2120-AA64


Airworthiness Directives; International Aero Engines AG Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) 
2021-11-15, which applies to certain International Aero Engines AG 
(IAE) V2500 model turbofan engines. AD 2021-11-15 requires performance 
of an ultrasonic inspection (USI) of the high-pressure turbine (HPT) 
1st-stage disk and HPT 2nd-stage disk and, depending on the results of 
the inspections, replacement of the HPT 1st-stage disk or HPT 2nd-stage 
disk. Since the FAA issued AD 2021-11-15, the FAA determined the need 
to clarify the compliance time for inspection of any HPT 1st-stage disk 
or HPT 2nd-stage disk that is installed on a low-thrust model engine 
but had been previously operated on a high-thrust model engine. This 
proposed AD would require performance of a USI of the HPT 1st-stage 
disk and HPT 2nd-stage disk and, depending on the results of the 
inspections, replacement of the HPT 1st-stage disk or HPT 2nd-stage 
disk. 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 December 
13, 2021.

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 
International Aero Engines AG, 400 Main Street, East Hartford, CT 
06118; phone: (800) 565-0140; email: [email protected]; website: 
https://connect.prattwhitney.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 at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0835; 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.

FOR FURTHER INFORMATION CONTACT: Alberto Hernandez, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7329; fax: (781) 238-7199; email: 
[email protected].

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 ADDRESSES. Include ``Docket No. FAA-2021-0835; Project Identifier 
AD-2021-00971-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 
the proposal 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 we receive about this proposed AD.

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 NPRM

[[Page 59659]]

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 NPRM, 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 NPRM. Submissions containing CBI should be 
sent to Alberto Hernandez, 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.

Background

    The FAA issued AD 2021-11-15, Amendment 39-21577 (86 FR 30380, June 
8, 2021), (AD 2021-11-15), for all IAE V2522-A5, V2524-A5, V2525-D5, 
V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, V2531-E5, and 
V2533-A5 model turbofan engines with a certain HPT 1st-stage disk or 
HPT 2nd-stage disk installed. AD 2021-11-15 was prompted by an event 
involving an uncontained failure of an HPT 1st-stage disk that resulted 
in high-energy debris penetrating the engine cowling. On March 18, 
2020, an Airbus Model A321-231 airplane, powered by IAE V2533-A5 model 
turbofan engines, experienced an uncontained HPT 1st-stage disk failure 
that resulted in an aborted takeoff. The uncontained failure of the HPT 
1st-stage disk resulted in high-energy debris penetrating the engine 
cowling. The FAA published Emergency AD 2020-07-51 on March 21, 2020 
(followed by publication in the Federal Register on April 13, 2020, as 
a Final Rule, Request for Comments (85 FR 20402)) and AD 2021-01-03 on 
January 6, 2021 (86 FR 458), to remove from service HPT 1st-stage and 
HPT 2nd-stage disks identified as having the highest risk of failure. 
Based on the root cause analysis performed since that event, the 
manufacturer identified a population of HPT 1st-stage disks and HPT 
2nd-stage disks that require inspection and possible removal from 
service. AD 2021-11-15 requires the performance of an USI of the HPT 
1st-stage disk and HPT 2nd-stage disk and, depending on the results of 
the inspections, replacement of the HPT 1st-stage disk or HPT 2nd-stage 
disk. The agency issued AD 2021-11-15 to prevent failure of the HPT 
1st-stage disk and HPT 2nd-stage disk.

Actions Since AD 2021-11-15 Was Issued

    Since the FAA issued AD 2021-11-15, the FAA determined the need to 
clarify the compliance time for inspection of any HPT 1st-stage disk or 
HPT 2nd-stage disk that is installed on a V2500 low-thrust model engine 
but that had been previously operated on a V2500 high-thrust model 
engine. The manufacturer categorizes V2527E-A5, V2527M-A5, V2528-D5, 
V2530-A5, and V2533-A5 model turbofan engines as high-thrust model 
engines and V2522-A5, V2524-A5, V2525-D5, and V2527-A model turbofan 
engines as low-thrust model engines. The FAA determined that any HPT 
1st-stage disk and HPT 2nd-stage disk that was operated on a high-
thrust model engine must follow shortened compliance thresholds.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Related Service Information Under 1 CFR part 51

    The FAA reviewed IAE Non-Modification Service Bulletin (NMSB) No. 
V2500-ENG-72-0713, Revision 1, dated January 26, 2021. This NMSB 
identifies the affected HPT 1st-stage disks and HPT 2nd-stage disks on 
IAE V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, 
V2528-D5, V2530-A5, and V2533-A5 model turbofan engines and specifies 
procedures for a USI of the HPT 1st-stage disk and HPT 2nd-stage disk. 
The Director of the Federal Register approved IAE NMSB V2500-ENG-72-
0713, Revision 1, dated January 26, 2021 for incorporation by reference 
as of July 13, 2021 (86 FR 30380, June 8, 2021).
    The FAA also reviewed IAE NMSB No. V2500-E5-72-0015, Revision 1, 
dated August 10, 2021. This NMSB identifies the affected HPT 1st-stage 
disks and HPT 2nd-stage disks on IAE V2531-E5 model turbofan engines 
and specifies procedures for a USI of the HPT 1st-stage disk and HPT 
2nd-stage 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 ADDRESSES.

Proposed AD Requirements in This NPRM

    This proposed AD would retain certain requirements of AD 2021-11-
15. This proposed AD would require the performance of an USI of the HPT 
1st-stage disk and HPT 2nd-stage disk and, depending on the results of 
the inspections, replacement of the HPT 1st-stage disk or HPT 2nd-stage 
disk.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 1,100 engines installed on airplanes of U.S. registry.
    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 the HPT 1st-stage disk and HPT 2nd- 20 work-hours x $85 per               $0          $1,700      $1,870,000
 stage disk.                             hour = $1,700.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacement 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 this replacement:

[[Page 59660]]



                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace the HPT 1st-stage disk or HPT 2nd-      0 work-hours x $85 per hour = $0        $300,000        $300,000
 stage disk.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this 
proposed AD may be covered under warranty, thereby reducing the cost 
impact on affected individuals.

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 that the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would 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:
0
a. Removing Airworthiness Directive AD 2021-11-15, Amendment 39-21577 
(86 FR 30380, June 8, 2021); and
0
b. Adding the following new airworthiness directive:

International Aero Engines AG: Docket No. FAA-2021-0835; Project 
Identifier AD-2021-00971-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) action by December 13, 2021.

(b) Affected ADs

    This AD replaces AD 2021-11-15, Amendment 39-21577 (86 FR 30380, 
June 8, 2021) (AD 2021-11-15).

(c) Applicability

    This AD applies to International Aero Engines AG (IAE) V2522-A5, 
V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-
A5, V2531-E5, and V2533-A5 model turbofan engines with an installed:
    (1) High-pressure turbine (HPT) 1st-stage disk, part number (P/
N) 2A5001, with a serial number (S/N) listed in Appendix A, Table 1, 
of IAE Non-Modification Service Bulletin (NMSB) No. V2500-ENG-72-
0713, Revision 1, dated January 26, 2021 (IAE NMSB V2500-ENG-72-
0713, Revision 1) or IAE NMSB No. V2500-E5-72-0015, Revision 1, 
dated August 10, 2021 (IAE NMSB V2500-E5-72-0015, Revision 1); or
    (2) HPT 2nd-stage disk, P/N 2A4802, with an S/N listed in 
Appendix A, Table 2, of IAE NMSB V2500-ENG-72-0713, Revision 1, or 
IAE NMSB V2500-E5-72-0015, Revision 1.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by an analysis performed by the 
manufacturer after an event involving an uncontained failure of a 
HPT 1st-stage disk that resulted in high-energy debris penetrating 
the engine cowling. The FAA is issuing this AD to prevent failure of 
the HPT 1st-stage disk and HPT 2nd-stage disk. The unsafe condition, 
if not addressed, could result in uncontained HPT disk failure, 
damage to the engine, damage to the airplane, and loss of the 
airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) For IAE V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, and V2533-
A5 model turbofan engines with an HPT 1st-stage disk, P/N 2A5001, 
with an S/N listed in Appendix A, Table 1, of IAE NMSB V2500-ENG-72-
0713, Revision 1, within the compliance time specified in Figure 1 
to paragraph (g)(1) of this AD, or within 10 flight cycles (FCs) 
after the effective date of this AD, whichever occurs later, perform 
an ultrasonic inspection (USI) of the HPT 1st-stage disk using the 
Accomplishment Instructions, paragraph 6, of IAE NMSB V2500-ENG-72-
0713, Revision 1.

[[Page 59661]]

[GRAPHIC] [TIFF OMITTED] TP28OC21.000

    Note 1 to paragraph (g)(1): The USI required by paragraphs 
(g)(1) through (6) of this AD requires the HPT 1st-stage disk and 
HPT 2nd-stage disks to be removed from the engine allowing piece-
part opportunity inspections. Per the Airworthiness Limitations 
Section of the manufacturer's Instructions for Continued 
Airworthiness, the additional inspections are not required unless 
the part has more than 100 FCs since the last piece-part opportunity 
inspection, is damaged, or is the cause for the removal of the 
engine. Engine removal for the purposes of complying with this AD is 
not ``cause'' for removal as stated in the Airworthiness Limitations 
Section.
    (2) For IAE V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, and V2533-
A5 model turbofan engines with an HPT 2nd-stage disk, P/N 2A4802, 
with an S/N listed in Appendix A, Table 2, of IAE NMSB V2500-ENG-72-
0713, Revision 1, within the compliance time specified in Figure 1 
to paragraph (g)(1) of this AD, or within 10 FCs after the effective 
date of this AD, whichever occurs later, perform a USI of the HPT 
2nd-stage disk using the Accomplishment Instructions, paragraph 7, 
of IAE NMSB V2500-ENG-72-0713, Revision 1.
    (3) For IAE V2522-A5, V2524-A5, V2525-D5, and V2527-A5 model 
turbofan engines with an HPT 1st-stage disk, P/N 2A5001, with an S/N 
listed in Appendix A, Table 1, of IAE NMSB V2500-ENG-72-0713, 
Revision 1, within the following compliance times, perform a USI of 
the HPT 1st-stage disk using the Accomplishment Instructions, 
paragraph 6, of IAE NMSB V2500-ENG-72-0713, Revision 1:
    (i) If the affected HPT 1st-stage disk has not operated at any 
time in an IAE V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, or V2533-A5 
model turbofan engine, perform the inspection within the compliance 
time specified in Figure 2 to paragraph (g)(3)(i) of this AD, or 
within 10 FCs after the effective date of this AD, whichever occurs 
later; or
[GRAPHIC] [TIFF OMITTED] TP28OC21.001

    (ii) If the affected HPT 1st-stage disk has operated at any time 
in an IAE V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, or V2533-A5 
model turbofan engine, perform the inspection within the compliance 
time specified in Figure 1 to paragraph (g)(1) of this AD, or within 
10 FCs after the effective date of this AD, whichever occurs later.
    (4) For IAE V2522-A5, V2524-A5, V2525-D5, and V2527-A5 model 
turbofan engines with an HPT 2nd-stage disk, P/N 2A4802, with an S/N 
listed in Appendix A, Table 2, of IAE NMSB V2500-ENG-72-0713, 
Revision 1, within the following compliance times, perform a USI of 
the HPT 2nd-stage disk using the Accomplishment Instructions, 
paragraph 7, of IAE NMSB V2500-ENG-72-0713, Revision 1:
    (i) If the affected HPT 2nd-stage disk has not operated at any 
time in an IAE V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, or V2533-A5 
model turbofan engine, perform the inspection within the compliance 
time specified in Figure 2 to paragraph (g)(3)(i) of this AD, or 
within 10 FCs after the effective date of this AD, whichever occurs 
later; or
    (ii) If the affected HPT 2nd-stage disk has operated at any time 
in an IAE V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, or V2533-A5 
model turbofan engine, perform the inspection within the compliance 
time specified in Figure 1 to paragraph (g)(1) of this AD, or within 
10 FCs after the effective date of this AD, whichever occurs later.
    (5) For IAE V2531-E5 model turbofan engines with an HPT 1st-
stage disk, P/N 2A5001, with an S/N listed in Appendix A, Table 1, 
of IAE NMSB V2500-E5-72-0015, Revision 1, within the compliance time 
specified in Figure 1 to paragraph (g)(1) of this AD, or within 10 
FCs after the effective date of this AD, whichever occurs later, 
perform a USI of the HPT 1st-stage disk using the Accomplishment 
Instructions, paragraph 6, of IAE NMSB V2500-E5-72-0015, Revision 1.
    (6) For IAE V2531-E5 model turbofan engines with an HPT 2nd-
stage disk, P/N 2A4802, with an S/N listed in Appendix A, Table 2, 
of IAE NMSB V2500-E5-72-0015, Revision 1, within the compliance time 
specified in Figure 1 to paragraph (g)(1) of this AD, or within 10 
FCs after the effective date of this AD, whichever occurs later, 
perform a USI of the HPT 2nd-stage disk using the Accomplishment 
Instructions, paragraph 7, of IAE NMSB V2500-E5-72-0015, Revision 1.
    (7) If, during the USI required by paragraphs (g)(1) through (6) 
of this AD, an HPT 1st-stage disk or HPT 2nd-stage disk does not 
pass the inspection as specified in the Accomplishment Instructions, 
paragraph 8, of IAE NMSB V2500-ENG-72-0713, Revision 1, or IAE NMSB 
V2500-E5-72-0015, Revision 1, as applicable, before further flight, 
remove the HPT 1st-stage disk or 2nd-stage disk, as applicable, from 
service and replace with a part eligible for installation.

(h) Definitions

    (1) 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 flanges, H-P, except for 
the following situations, which do not constitute an engine shop 
visit.
    (i) Separation of engine flanges solely for the purposes of 
transportation without subsequent engine maintenance.
    (ii) Engine removal for the purpose of performing field 
maintenance activities at a maintenance facility in lieu of 
performing them on-wing.
    (2) For the purpose for this AD, a ``part eligible for 
installation'' is:

[[Page 59662]]

    (i) An HPT 1st-stage disk or HPT 2nd-stage disk listed in 
Appendix A, Tables 1 and 2, of IAE NMSB V2500-ENG-72-0713, Revision 
1, or Appendix A, Tables 1 and 2, of IAE NMSB V2500-E5-72-0015, 
Revision 1, that passed the USI required by paragraphs (g)(1) 
through (6) of this AD; or
    (ii) An HPT 1st-stage disk or HPT 2nd-stage disk that is not 
listed in Appendix A, Tables 1 and 2, of IAE NMSB V2500-ENG-72-0713, 
Revision 1, or Appendix A, Tables 1 and 2, of IAE NMSB V2500-E5-72-
0015, Revision 1.

(i) Credit for Previous Actions

    You may take credit for the USI of the HPT 1st-stage disk and 
HPT 2nd-stage disk required by paragraphs (g)(5) and (6) of this AD 
and the replacement of the HPT 1st-stage disk and HPT 2nd-stage disk 
required by paragraph (g)(7) of this AD, if you performed these 
actions before the effective date of this AD in accordance with IAE 
NMSB No. V2500-E5-72-0015, original issue, dated December 15, 2020.

(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)(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.

(k) Related Information

    (1) For more information about this AD, contact Alberto 
Hernandez, Aviation Safety Engineer, ECO Branch, FAA, 1200 District 
Avenue, Burlington, MA 01803; phone: (781) 238-7329; fax: (781) 238-
7199; email: [email protected].
    (2) For service information identified in this AD, contact 
International Aero Engines AG, 400 Main Street, East Hartford, CT 
06118; phone: (800) 565-0140; email: [email protected]; 
website: https://connect.prattwhitney.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 September 23, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-23180 Filed 10-27-21; 8:45 am]
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