81 FR 65265 - Airworthiness Directives; International Aero Engines AG Turbofan Engines

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 81, Issue 184 (September 22, 2016)

We are adopting a new airworthiness directive (AD) for certain International Aero Engines AG (IAE) V2500-A1 turbofan engines. This AD was prompted by a report of an uncontainment caused by a high-pressure turbine (HPT) seal release. This AD requires removing the HPT No. 4 bearing front seal seat, part numbers (P/Ns) 2A0066, 2A1998, and 2A3432, and the HPT No. 4 bearing rear seal seat, P/Ns 2A0067, 2A1999, and 2A3433, and replacing them with parts eligible for installation. This AD also requires inspecting the HPT rotor and stator assembly, and, if necessary, their replacement with parts that are eligible for installation. We are issuing this AD to prevent failure of the HPT stage 2 seals, uncontained HPT seal release, damage to the engine, and damage to the airplane.

[Federal Register Volume 81, Number 184 (Thursday, September 22, 2016)]
[Rules and Regulations]
[Pages 65265-65267]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-22703]



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Federal Register / Vol. 81, No. 184 / Thursday, September 22, 2016 / 
Rules and Regulations

[[Page 65265]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-5392; Directorate Identifier 2016-NE-10-AD; 
Amendment 39-18654; AD 2016-19-05]
RIN 2120-AA64


Airworthiness Directives; International Aero Engines AG Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
International Aero Engines AG (IAE) V2500-A1 turbofan engines. This AD 
was prompted by a report of an uncontainment caused by a high-pressure 
turbine (HPT) seal release. This AD requires removing the HPT No. 4 
bearing front seal seat, part numbers (P/Ns) 2A0066, 2A1998, and 
2A3432, and the HPT No. 4 bearing rear seal seat, P/Ns 2A0067, 2A1999, 
and 2A3433, and replacing them with parts eligible for installation. 
This AD also requires inspecting the HPT rotor and stator assembly, 
and, if necessary, their replacement with parts that are eligible for 
installation. We are issuing this AD to prevent failure of the HPT 
stage 2 seals, uncontained HPT seal release, damage to the engine, and 
damage to the airplane.

DATES: This AD is effective October 27, 2016.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 27, 
2016.

ADDRESSES: For service information identified in this final rule, 
contact International Aero Engines AG, 400 Main Street, East Hartford, 
CT 06118; phone: 800-565-0140; email: [email protected]; Internet: 
http://fleetcare.pw.utc.com. You may view this service information at 
the FAA, Engine & Propeller Directorate, 1200 District Avenue, 
Burlington, MA. For information on the availability of this material at 
the FAA, call 781-238-7125. It is also available on the Internet at 
http://www.regulations.gov by searching for and locating Docket No. 
FAA-2016-5392.

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-2016-
5392; 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 AD, 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: Brian Kierstead, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 
District Avenue, Burlington, MA 01803; phone: 781-238-7772; 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 IAE V2500-A1 
turbofan engines. The NPRM published in the Federal Register on April 
13, 2016 (81 FR 21768). The NPRM was prompted by a report of an 
uncontainment caused by a HPT seal release. The NPRM proposed to 
require removing from service the HPT No. 4 bearing front seal seat, P/
Ns 2A0066, 2A1998, and 2A3432, and the HPT No. 4 bearing rear seal 
seat, P/Ns 2A0067, 2A1999, and 2A3433, and replacement with parts 
eligible for installation. This AD would also require inspecting the 
HPT rotor and stator assembly, and, if necessary, their replacement 
with parts that are eligible for installation. 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 AD. The following presents the comments received on the NPRM (81 
FR 21768, April 13, 2016) and the FAA's response to each comment.

Request To Allow Monitoring of Oil Consumption and Monitoring Analysis

    Air India Ltd. (AIL) commented that the fracture of the HPT stage 2 
seal is a known problem with the type design. AIL does not agree that 
the root cause of the failure is clogged No. 4 bearing seal seats. AIL 
finds that increases in oil consumption and/or vibration signature are 
precursors to failure of the HPT stage 2 seal. We interpret AIL's 
comment as a request to allow monitoring of oil consumption rate and 
vibration signature analysis instead of the requirements of this AD.
    We disagree. We disagree with AIL's analysis of the unsafe 
condition because although other failure modes leading to fracture of 
the HPT stage 2 seal exist, the uncontained part release noted in the 
NPRM (81 FR 21768, April 13, 2016) was caused by blockage of the No. 4 
bearing seal seat's anti-weep circuit. We disagree with allowing oil 
consumption monitoring and vibration signature analysis because they do 
not provide an acceptable level of safety for engines with seal seats 
processed using methods susceptible to oil blockage. We did not change 
this AD.

Request To Delay Compliance

    AIL commented that we should delay compliance to this AD until 
December 31, 2017. This additional time to comply with this AD would 
allow for minimal disruption to its fleet operations. AIL indicated 
that fleet safety would be maintained through engine oil consumption 
monitoring and vibration signature analysis.
    We disagree. As noted in our previous comment response, oil 
consumption monitoring and vibration signature analysis do not provide 
an acceptable level of safety for engines with seal seats processed 
using methods susceptible to oil blockage. We did not change this AD.

[[Page 65266]]

Request To Revise Applicability

    AIL commented that the applicability of this AD should not be 
limited to the IAE V2500-A1 fleet.
    We disagree. The applicability of this AD is limited to the IAE 
V2500-A1 engines with affected serial numbers because this population 
of engines has been identified as having been processed using methods 
that could lead to failure of the HPT stage 2 seals. We did not change 
this AD.

Request To Include End Date for Compliance

    IAE and Airbus commented that we should include an end date of 
December 31, 2016, for compliance with this AD.
    We disagree. Our analysis of the unsafe condition determined that 
blockage of the No. 4 bearing seal seat anti-weep grooves is a function 
of engine cycles rather than time in service. We therefore did not base 
compliance on a calendar date. We did not change this AD.

Request To Require Oil Monitoring and Turbine Case Inspection

    IAE and Airbus commented that not mandating oil monitoring and 
inspection of the turbine case weep-hole may increase risk to operators 
if they follow only the requirements of this AD. IAE indicated that 
this AD should match the compliance requirements of IAE SB V2500-ENG-
72-0670, dated March 14, 2016.
    We disagree. We find that the actions required by this AD 
adequately address the unsafe condition represented by the possibility 
of failure of the HPT stage 2 seals while not imposing unnecessary 
burdens on operators. We did not change this AD.

Revision to Compliance

    We revised the compliance section to allow installed No. 4 bearing 
front and rear seal seats to be returned to service following removal 
and refurbishment.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD as proposed except for minor editorial changes. We have 
determined that these minor changes:
     Are consistent with the intent that was proposed in the 
NPRM (81 FR 21768, April 13, 2016) for correcting the unsafe condition; 
and
     Do not add any additional burden upon the public than was 
already proposed in the NPRM (81 FR 21768, April 13, 2016).

Related Service Information Under 1 CFR Part 51

    We reviewed IAE Non-Modification Service Bulletin (NMSB) V2500-ENG-
72-0670, dated March 14, 2016. The NMSB identifies affected engines and 
provides guidance for replacing the No. 4 bearing front and rear seal 
seats and for inspecting the HPT rotor and stator assembly. 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 0 engines installed on airplanes 
of U.S. registry. We estimate that it will take about 10 hours to 
perform the seal seat replacement. The average labor rate is $85 per 
hour. We also estimate the cost of No. 4 bearing front and rear seal 
seats to be $13,562. Based on these figures, we estimate the cost of 
this AD on U.S. operators to be $0.

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.

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 to the extent 
that it justifies making a regulatory distinction, 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):

2016-19-05 International Aero Engines AG: Amendment 39-18654; Docket 
No. FAA-2016-5392; Directorate Identifier 2016-NE-10-AD.

(a) Effective Date

    This AD is effective October 27, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to International Aero Engines AG (IAE) V2500-A1 
turbofan engines with serial numbers listed under Planning 
Information, Effectivity Data in IAE Non-Modification Service 
Bulletin (NMSB) V2500-ENG-72-0670, dated March 14, 2016.

(d) Unsafe Condition

    This AD was prompted by a report of an uncontainment caused by a 
high-pressure turbine (HPT) seal release. We are issuing this AD to 
prevent failure of the HPT stage 2 seal, uncontained HPT seal 
release, damage to the engine, and damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) Prior to accumulating 500 cycles in service after the 
effective date of this AD,
    (i) Remove the No. 4 bearing front seal seat, part numbers (P/
Ns) 2A0066, 2A1998, 2A3432; and the No. 4 bearing rear seal seat, P/
Ns 2A0067, 2A1999, 2A3433, and replace with parts eligible for 
installation.
    (ii) Inspect the HPT rotor and stator assembly. Use the 
Accomplishment

[[Page 65267]]

Instructions, Part C, paragraph 1.B. of IAE NMSB V2500-ENG-72-0670, 
dated March 14, 2016 to perform the inspection.
    (2) For any parts that fail the inspection required by paragraph 
(e)(1)(ii) of this AD, before further flight, remove and replace 
with parts eligible for installation.

(f) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request. You may email your request to: [email protected].

(g) Related Information

    For more information about this AD, contact Brian Kierstead, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7772; fax: 781-238-7199; email: 
[email protected].

(h) 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) International Aero Engines AG (IAE) Non-Modification Service 
Bulletin V2500-ENG-72-0670, dated March 14, 2016.
    (ii) Reserved.
    (3) For IAE 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]; Internet: 
http://fleetcare.pw.utc.com.
    (4) You may view this service information at the FAA, Engine & 
Propeller Directorate, 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 September 15, 2016.
Ann C. Mollica,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-22703 Filed 9-21-16; 8:45 am]
BILLING CODE 4910-13-P