2012-01-10: Fan drive shaft

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): 2012-01-10 General Electric Company: Amendment 39-16922; Docket No. FAA-2011-0599; Directorate Identifier 2011-NE-19-AD. (a) Effective Date This AD is effective February 27, 2012. (b) Affected ADs None. (c) Applicability This AD applies to General Electric Company (GE) CF34-10E series turbofan engines, serial number (S/N) 994116, and S/Ns 994118 through 994187, inclusive. (d) Unsafe Condition This AD was prompted by a report of heavy wear found on the seating surface of the center vent duct (CVD) (commonly referred to as center vent tube) support ring and on the inside diameter of the fan drive shaft at the mating location. The wear is caused by relative motion between the CVD support assembly (consisting of self-locking nut, part number (P/N) 2226M57G03, threaded sleeve, P/N 2226M55P03, and support ring, P/N 2226M56P01) and the fan drive shaft, during engine operation. We are issuing this AD to prevent fan drive shaft failure, leading to uncontained engine failure and damage to the airplane. (e) Compliance Comply with this AD before accumulating 11,500 total cycles-in- service on the engine, unless already done. (f) Removal from Service of CVD Support Assembly and Determination of Fan Drive Shaft Serviceability Visually inspect the seating surface of the CVD support ring for wear. (1) If there is sign of wear on the CVD support ring, remove the CVD support assembly and the fan drive shaft from service before further flight. (2) If there is no sign of wear on the CVD support ring, remove the CVD support assembly from service and borescope inspect the inside diameter of the fan drive shaft at the CVD support ring contact area for wear. (3) If there is sign of wear on the inside diameter of the fan drive shaft, remove the fan drive shaft from service before further flight. (g) Installation Prohibition After the effective date of this AD, do not return to service any CVD support assembly (consisting of self-locking nut, P/N 2226M57G03, threaded sleeve, P/N 2226M55P03, and support ring, P/N 2226M56P01) or fan drive shaft removed from service as specified in this AD. (h) Definition For the purposes of this AD, the phrase ``sign of wear'' is defined as any visual indication of removal of parent material from the CVD seating surface or the fan drive shaft. [[Page 3090]] (i) 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. (j) Related Information (1) For more information about this AD, contact John Frost, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: (781) 238-7756; fax: (781) 238-7199; email: john.frost@faa.gov. (2) GE Service Bulletin No. CF34-10E S/B 72-0188, dated April 12, 2011, pertains to the subject of this AD. For service information identified in this AD, contact GE-Aviation, M/D Rm. 285, One Neumann Way, Cincinnati, OH 45215, phone: (513) 552-3272; email: geae.aoc@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. (k) Material Incorporated by Reference None.