# AD 2018-03-22: Turbine Section - Type: Airworthiness directive - Status: Historical - Products: GE Aviation Czech s.r.o. M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-11S and M601F - Effective: March 21, 2018 - Published: February 14, 2018, 83 FR 6455–6456 - Issued: February 8, 2018 - Issued as: Final rule - Superseded by: [AD 2020-15-03](https://openairdocs.org/ad/2020-15-03) - Product type: Engine - ATA chapter: 72 · Engine - Amendment: 39-19195 - Docket: FAA-2017-0658 (https://www.regulations.gov/docket/FAA-2017-0658) - Registered aircraft: 48 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/28/8d/288dadfaefbcaabdd5568d82a81ae10f97d7999b72fd024d9c0d1805c1c18f97 (from https://www.govinfo.gov/content/pkg/FR-2018-02-14/pdf/2018-02994.pdf) - Federal Register: https://www.federalregister.gov/documents/2018/02/14/2018-02994/airworthiness-directives-ge-aviation-czech-sro-turboprop-engines - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/8C75F2742D4DCAFE86258234004F823E.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/2018-03-22 ## 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. ## The airworthiness directive 1. The authority citation for part 39 continues to read as follows: 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: ANE-AD-AMOC@faa.gov. (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: 781-238-7754; fax: 781-238-7199; email: robert.green@faa.gov. (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. ## Rule preamble ### 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: +420 222 538 111; fax: +420 222 538 222. 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. ### For further information contact Robert Green, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7754; fax: 781-238-7199; email: robert.green@faa.gov. ### 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. ### Adoption of the Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS E00048EN](https://openairdocs.org/tcds/E00048EN): GE Aviation Czech s.r.o.; names 6 of 13 models: M601E-11AS, M601D-11, M601E-11A, M601E-11, M601F, M601E-11S ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 48 (0 by airframe model, 48 by engine model) - Makers: Air Tractor 2, Ayres 2, Beech 2, 293rg 1, Aero Commander 1, Aircraft Builders One 1, Ameriflight Management Svcs 1, Arnold Vasenden 1, Brewer Lance A 1, BT 750 1 Models with the most aircraft: - [Walter M601 series](https://openairdocs.org/engine/walter-m601-series): 28 aircraft (engine model) - [Walter M601E-11](https://openairdocs.org/engine/walter-m601e-11): 8 aircraft (engine model) - [Walter M601D-11](https://openairdocs.org/engine/walter-m601d-11): 7 aircraft (engine model) - [Walter M601E-11A](https://openairdocs.org/engine/walter-m601e-11a): 2 aircraft (engine model) - [GE AV M601E-11](https://openairdocs.org/engine/ge-av-m601e-11): 1 aircraft (engine model) - [GE AV M601D-11](https://openairdocs.org/engine/ge-av-m601d-11): 1 aircraft (engine model) - [Walter M601E-11S](https://openairdocs.org/engine/walter-m601e-11s): 1 aircraft (engine model) All 8 models: https://openairdocs.org/ad/2018-03-22/models.md Every aircraft: https://openairdocs.org/ad/2018-03-22/aircraft.md ## Related documents - [AD 2020-15-03](https://openairdocs.org/ad/2020-15-03): Turbine Section · GE Aviation Czech s.r.o. M601D-11, M601E-11, M601E-11A and 3 more. Effective Aug 31, 2020. Supersedes this AD - [Proposed rule FAA-2017-0658](https://openairdocs.org/proposed/FAA-2017-0658): Notice of proposed rulemaking (NPRM), published Sep 22, 2017 Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.