# AD 2011-19-03: Accessory gearbox (AGB) - Type: Airworthiness directive - Status: Current - Products: General Electric CT7-8, CT7-8A, CT7-8A1, CT7-8E and CT7-8F5 - Effective: November 9, 2011 - Published: October 5, 2011, 76 FR 61559–61561 - Issued: September 8, 2011 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-16808 - Docket: FAA-2011-0392 (https://www.regulations.gov/docket/FAA-2011-0392) - Project: 2011-NE-12-AD - Registered aircraft: 112 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/d3/ba/d3bad8c958dbf07bc2feb75e73f3fbbf760fe86384ea506d2eadb1cc8dde77dd (from https://www.govinfo.gov/content/pkg/FR-2011-10-05/pdf/2011-25654.pdf) - Federal Register: https://www.federalregister.gov/documents/2011/10/05/2011-25654/airworthiness-directives-general-electric-company-ge-ct7-8-ct7-8a-ct7-8a1-ct7-8e-and-ct7-8f5 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E145658453EC8AA38625792000485D11.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/2011-19-03 ## Summary We are adopting a new airworthiness directive (AD) for the products listed above. This AD was prompted by four reports of unrecoverable engine stalls, during hover in a left-roll attitude. This AD requires the installation of an accessory gearbox (AGB) axis-A oil slinger nut to the axis-A shaft assembly. We are issuing this AD to prevent an unrecoverable engine stall, leading to a helicopter forced landing or accident. ## 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): 2011-19-03 General Electric Company: Amendment 39-16808; Docket No. FAA-2011-0392; Directorate Identifier 2011-NE-12-AD. ### (a) Effective Date (a) This AD is effective November 9, 2011. ### (b) Affected ADs (b) None. ### (c) Applicability (c) This AD applies to the following General Electric Company (GE) turboshaft engines: (1) CT7-8, all engine serial numbers (S/Ns). (2) CT7-8A, engine S/Ns 947565 and below. (3) CT7-8A1, engine S/Ns 530017 and below. (4) CT7-8E, engine S/Ns 953068 and below, and S/Ns 953070 through 953072. (5) CT7-8F5, engine S/Ns 731005 and below, and S/Ns 731007, 731008, 817021, and 817022. ### (d) Unsafe Condition (d) This AD was prompted by four reports of unrecoverable engine stalls, during hover in a left-roll attitude. We are issuing this AD to prevent an unrecoverable engine stall, leading to a helicopter forced landing or accident. ### (e) Compliance (e) Comply with this AD at the next engine shop visit, the next 1,500-hour helicopter inspection, or before operation after next engine installation, whichever occurs first. ### (f) Installation of Accessory Gearbox (AGB) Axis-A Oil Slinger Nut (f) Install the AGB axis-A oil slinger nut to the axis-A shaft assembly. Use Accomplishment Instructions, paragraphs 3.A. through 3.C. of GE Aircraft Engines CT7-8 Turboshaft Engine Service Bulletin No. CT7-8 S/B 72-0033, Revision 1, dated April 28, 2011, to do the installation. ### (g) Previous Credit (g) An oil slinger nut installation performed before the effective date of this AD using GE Aircraft Engines CT7-8 Turboshaft Engine Service Bulletin No. CT7-8 S/B 72-0033, dated February 11, 2011, satisfies the installation requirements of this AD. ### (h) Alternative Methods of Compliance (AMOCs) (h) The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. ### (i) Related Information (i) For more information about this AD, contact Walter Meibaum, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7119; fax: 781-238-7199; e-mail: walter.meibaum@faa.gov. ### (j) Material Incorporated by Reference (j) You must use the following service information to do the actions required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference (IBR) under 5 U.S.C. 552(a) and 1 CFR part 51 of the following service information on the date specified: (1) GE Aircraft Engines CT7-8 Turboshaft Engine Service Bulletin No. CT7-8 S/B 72-0033, Revision 1, dated April 28, 2011, approved for IBR November 9, 2011. (2) For service information identified in this AD, contact GE-Aviation, M/D Rm. 285, One Neumann Way, Cincinnati, OH 45215; phone: 513-552-3272; e-mail: geaeaoc@ge.com. (3) You may review copies of the 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. (4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at an NARA facility, call 202-741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. ## Rule preamble ### Dates This AD is effective November 9, 2011. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of November 9, 2011. ### Addresses For service information identified in this AD, contact GE-Aviation, M/D Rm. 285, One Neumann Way, Cincinnati, OH 45215; phone: 513-552-3272; e-mail: geaeaoc@ge.com. You may review copies of the referenced 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. ### For further information contact Walter Meibaum, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7119; fax: 781-238-7199; e-mail: walter.meibaum@faa.gov. ### Discussion We received four reports of GE CT7-8 series turboshaft helicopter engines experiencing unrecoverable engine stalls, during hover in a left-roll attitude. Investigation revealed that during a prolonged left roll, excessive return oil from the AGB may return to the A-sump and exceed the sump's scavenging capability. The sump then floods, leading to over-heated oil, which preheats the air entering the engine's compressor. This preheated air causes inlet thermal distortion. This condition, if not corrected, could result in an unrecoverable engine stall, leading to a helicopter forced landing or accident. We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM published in the Federal Register on May 2, 2011 (76 FR 24407). That NPRM proposed to require the installation of an AGB axis-A oil slinger nut to the axis-A shaft assembly. ### Comments We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM published in the Federal Register on May 2, 2011 (76 FR 24407). Since we issued the NPRM published in the Federal Register on May 2, 2011 (76 FR 24407), GE issued a revision to the service bulletin we are incorporating by reference in this AD. The revision includes new information in the procedure required to torque the oil slinger nut. This AD incorporates by reference, GE Aircraft Engines CT7-8 Turboshaft Engine Service Bulletin No. CT7-8 S/B 72-0033, Revision 1, dated April 28, 2011. Also since we issued the NPRM published in the Federal Register on May 2, 2011 (76 FR 24407), we discovered that in the applicability paragraph, we inadvertently omitted engine serial number 953071. We corrected that omission in paragraph (c) (4) by changing “CT7-8E, engine S/Ns 953068 and below, and S/Ns 953070 and 953072” to “CT7-8E, engine S/Ns 953068 and below, and S/Ns 953070 through 953072”. ### Conclusion We reviewed the relevant data and determined that air safety and the public interest require adopting the 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 published in the Federal Register on May 2, 2011 (76 FR 24407) for correcting the unsafe condition. ### Costs of Compliance We estimate that this AD will affect 80 engines installed on helicopters of U.S. registry. We also estimate that it will take about one work-hour per engine to perform the actions required by this AD, and that the average labor rate is $85 per work-hour. Required parts will cost about $700 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $62,800. ### 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, 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 E8NE](https://openairdocs.org/tcds/E8NE): General Electric Company GE Aviation; names 5 of 30 models: CT7-8E, CT7-8A, CT7-8F5, CT7-8, CT7-8A1 ## 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: 112 (0 by airframe model, 112 by engine model) - Makers: Sikorsky 46, Saab-Scania 34, Bell 15, Construcciones Aeronauticas 5, Bell Helicopter Textron 3, Saab-Fairchild 3, Agustawestland 2, Leonardo S P A 2, Keystone Helicopter 1, Saab 1 Models with the most aircraft: - [GE CT7-SER series](https://openairdocs.org/engine/ge-ct7-ser-series): 43 aircraft (engine model) - [GE CT7-8A](https://openairdocs.org/engine/ge-ct7-8a): 43 aircraft (engine model) - [GE CT7 series](https://openairdocs.org/engine/ge-ct7-series): 26 aircraft (engine model) All 3 models: https://openairdocs.org/ad/2011-19-03/models.md Every aircraft: https://openairdocs.org/ad/2011-19-03/aircraft.md ## Related documents - [Proposed rule FAA-2011-0392](https://openairdocs.org/proposed/FAA-2011-0392): Notice of proposed rulemaking (NPRM), published May 2, 2011 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.