2018-02994. Airworthiness Directives; GE Aviation Czech s.r.o. Turboprop Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for GE Aviation Czech s.r.o. M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-11S, and M601F turboprop engines. This AD requires removal of certain power turbine (PT) disks installed on the affected engines. This AD was prompted by a design review by the manufacturer that determined PT rotors with certain disks have less overspeed margin than originally stated during product certification. We are issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective March 21, 2018.

ADDRESSES:

For service information identified in this final rule, contact GE Aviation Czech s.r.o., Beranových 65, 199 02 Praha 9—Letňany, Czech Republic; phone: [phone]; fax: [phone]. You may view this service information at the FAA, Engine & Propeller Standards Branch, 1200 District Avenue, Burlington, MA. 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 http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0658; 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 mandatory continuing airworthiness information (MCAI), the regulatory evaluation, any comments received, and other information. The address for the Docket Office (phone: [phone]) 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:

Robert Green, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: [phone]; fax: [phone]; email: [e-mail].

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 GE Aviation Czech s.r.o. M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-11S, and M601F turboprop engines. The NPRM published in the Federal Register on September 22, 2017 (82 FR 44355). The NPRM was prompted by a design review by the manufacturer that determined PT rotors with certain disks have less overspeed margin than originally stated during product certification. The NPRM proposed to require removal of the affected PT disks. We are issuing this AD to correct the unsafe condition on these products.

The MCAI states:

It was identified during a recent design review that power turbine (PT) rotors with certain disks, part number (P/N) M601-3220.6 and P/N M601-3220.7, have a reduction in the declared theoretical PT rotor overspeed limit.

This condition, if not corrected, may lead to high energy debris release in case of PT rotor overspeed occurrence, possibly resulting in damage to, and/or reduced control of, the aeroplane.

You may obtain further information by examining the MCAI in the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0658.

Comments

We gave the public the opportunity to participate in developing this final rule. We considered the comment received. Cody Hargis (not further identified) supported the NPRM.

Conclusion

We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting this final rule as proposed.

Related Service Information

We reviewed GE Aviation Czech s.r.o. Alert Service Bulletin (ASB) No. ASB-M601E-72-50-00-0069, ASB-M601D-72-50-00-0052, ASB-M601F-72-50-00-0035, ASB-M601T-72-50-00-0028, and ASB-M601Z-72-50-00-0038, (single document), dated February 21, 2017. The ASB describe procedures for replacing the PT disk.

Costs of Compliance

We estimate that this AD affects 50 engines installed on airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Disk removal and replacement	56 work-hours × $85 per hour = $4,760	$6,989	$11,749	$587,450

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.

This AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to engines, propellers, and associated appliances to the Manager, Engine and Propeller Standards Branch, Policy and Innovation Division.

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 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 Procedures (44 FR 11034, February 26, 1979),

(3) Will not affect intrastate aviation in Alaska, 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

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13 [

Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

2018-03-22 GE Aviation Czech s.r.o. (Type Certificate previously held by WALTER Engines a.s., Walter a.s., and MOTORLET a.s.): Amendment 39-19195; Docket No. FAA-2017-0658; Product Identifier 2017-NE-20-AD.

(a) Effective Date

This AD is effective March 21, 2018.

(b) Affected ADs

None.

(c) Applicability

This AD applies to GE Aviation Czech s.r.o. M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-11S, and M601F turboprop engines, with power turbine (PT) rotors with disks, part number (P/N) M601-3220.6 or P/N M601-3220.7, installed.

(d) Subject

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

(e) Unsafe Condition

This AD was prompted by a review by the manufacturer that determined that PT rotors with disks, P/N M601-3220.6 or P/N M601-3220.7, have less overspeed margin than originally declared during product certification. We are issuing this AD to prevent failure of the PT rotor. The unsafe condition, if not addressed, could result in failure of the PT rotor, uncontained release of the PT disk, 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

After the effective date of this AD, remove the affected PT disk from service during the next engine overhaul or rebuild, or within 5 years, whichever occurs first.

(h) Installation Prohibition

After the effective date of this AD, do not install an affected PT disk on any engine.

(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: [e-mail].

(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.

(j) Related Information

(1) For more information about this AD, contact Robert Green, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: [phone]; fax: [phone]; email: [e-mail].

(2) Refer to MCAI European Aviation Safety Agency AD 2017-0100, dated June 8, 2017, for more information. You may examine the MCAI in the AD docket on the internet at http://www.regulations.gov by searching for and locating it in Docket No. FAA-2017-0658.

(k) Material Incorporated by Reference

None.

Issued in Burlington, Massachusetts, on February 8, 2018.

Robert J. Ganley,

Manager, Engine and Propeller Standards Branch, Aircraft Certification Service.