AD 2013-26-09

Active

2nd-stage turbine disk

Key Information
2013-26-09
Active
February 14, 2014
January 06, 2014
FAA-2013-0575
39-17718
Applicability
["Engine"]
Not specified
Turbomeca S.A.
Astazou XIV B Astazou XIV H
Summary

We are adopting a new airworthiness directive (AD) for all Turbomeca S.A. ASTAZOU XIV B and XIV H engines. This AD was prompted by reports of cracks on the 2nd-stage turbine disk. This AD requires replacement of the 2nd-stage turbine disk. We are issuing this AD to prevent disk cracking, uncontained 2nd-stage turbine blade release, damage to the engine, and damage to the helicopter.

Action Required

Final rule.

Regulatory Text

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):

2013-26-09 Turbomeca S.A.: Amendment 39-17718; Docket No. FAA-2013- 0575; Directorate Identifier 2013-NE-21-AD.

(a) Effective Date

This AD becomes effective February 14, 2014.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all Turbomeca S.A. ASTAZOU XIV B and XIV H engines.

(d) Reason

This AD was prompted by reports of cracks on the 2nd-stage turbine disk. We are issuing this AD to prevent disk cracking, uncontained 2nd-stage turbine blade release, damage to the engine, and damage to the helicopter.(e) Actions and Compliance

Unless already done, do the following actions.
(1) For ASTAZOU XIV B engines that have not incorporated AB 138 modification remove the 2nd-stage turbine disk, part number (P/N) 0265260270, as follows:
(i) For engines with 1,800 or more engine cycles since new (CSN) or cycles since last overhaul (CSLO), remove the 2nd-stage turbine disk, P/N 0265260270, within 10 operating hours after the effective date of this AD.
(ii) For engines with less than 1,800 CSN or CSLO, remove the 2nd-stage turbine disk, P/N 0265260270, within 300 operating hours after the effective date of this AD or before 1,800 CSN or CSLO, whichever comes first.
(2) For ASTAZOU XIV B engines that have incorporated AB 138 modification, remove the 2nd-stage turbine disk, P/N 0283270200, with P/N 0265260270 written or scratched onto the disk, within 1,800 CSN or CSLO, or within 10 operating hours after the effective date of this AD, whichever occurs later.
(3) For ASTAZOUXIV H engines, remove the 2nd-stage turbine disk, P/N 0265260270, within 300 operating hours after the effective date of this AD.

(f) Alternative Methods of Compliance (AMOCs)

The Manager, Engine Certification Office, FAA, may approve AMOCs to this AD. Use the procedures found in 14 CFR 39.19 to make your request.

(g) Related Information

(1) For more information about this AD, contact Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7779; fax: 781-238-7199; email: frederick.zink@faa.gov.
(2) Refer to MCAI European Aviation Safety Agency airworthiness directive 2013-0111R1, dated June 3, 2013, for more information. You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2013-0575-0002.
(3) Turbomeca S.A. Alert Mandatory Service Bulletin (MSB) No. A283 72 0809, Version A, dated May 16,2013, and Turbomeca S.A. Alert MSB No. A283 72 0808, Version A, dated May 16, 2013, which are not incorporated by reference in this AD, can be obtained from Turbomeca S.A. using the contact information in paragraph (g)(4) of this AD.
(4) For service information identified in this AD, contact Turbomeca, S.A., 40220 Tarnos, France; phone: 33 (0)5 59 74 40 00; telex: 570 042; fax: 33 (0)5 59 74 45 15.
(5) You may view this service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125.

(h) Material Incorporated by Reference

None.

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 the specified products. The NPRM was published in the Federal Register on August 6, 2013 (78 FR 47581). The NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

Some cracks have been reported on the second stage turbine disc of ASTAZOU XIV engines inducted into a Repair Centre. These cracks are located in the serrations of the disc. The results of the technical investigation concluded that the cracks were present on non-shot peened second stage turbine discs (discs on which AB 138 modification was not incorporated), and on second stage turbine discs that were shot peened during their service life (discs on which AB 138 modification was incorporated after initial service use without shot peening). Until now, no crack has been reported on second stage turbine discs shot peened since new, these discs accounting for more than half of all ASTAZOU XIV flight hours. It was not possible to clearly identify what caused the cracks.
This condition, if not corrected, could lead to some events of disc serrations rupture, possibly resulting in uncontained second stage turbine blade release with consequent damage to, and reduced control of, the helicopter.

You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2013-0575-0002.
We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (78 FR 47581, August 6, 2013). However, we did make an editorial change to the preamble of this AD.

Conclusion

We reviewed the available data and determined that air safety and the public interest require adopting this AD with the changes described previously. We determined that these changes will not increase the economic burden on any operator or increase the scope of thisAD.

Costs of Compliance

We estimate that this AD will affect about 6 engines of U.S. registry. We also estimate that it will take about 5 hours per engine to comply with this AD. The average labor rate is $85 per hour. Required parts will cost about $6,560 per engine. Based on these figures, we estimate the cost of this AD on U.S. operators to be $41,910.

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

We determined that 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 this AD:
(1) Is not a ``significant regulatory action'' under Executive Order 12866,
(2) Is not a ``significant rule'' under the DOT Regulatory Policies and

[[Page 1734]]

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.
We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

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Contact Information

Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7779; fax: 781-238-7199; email: frederick.zink@faa.gov.

References
Federal Register Volume 79, Number 7 (Friday, January 10, 2014)
--- - Part 39
Pages 1733-1734
FAA Documents