2009-25-09: Main gearbox

2009-25-09 Eurocopter France: Amendment 39-16128. Docket No. FAA- 2009-1124; Directorate Identifier 2009-SW-35-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) becomes effective on December 29, 2009. \n\nOther Affected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Model SA 330 F, G, and J helicopters, all serial numbers, with main gearbox (MGB) input flexible coupling flange assemblies, part number (P/N) 330A-32937401, installed that have been modified per MOD 0752416 and MOD 0752419, but have not been subject to a maintenance scheduled inspection per Working Card 65.32.601 since new or since a complete overhaul of the MGB, certificated in any category. \n\nReason \n\n\t(d) The mandatory continuing airworthiness information (MCAI) AD states that there has been one report of disks failure of a flexible coupling on one of the MGB inputs, which may be the result of the loss of the tightening torque load, or insufficient tightening of the nuts on the bolts attaching the disks of the flexible coupling to its sliding and fixed flanges. This condition, if not corrected, could result in progressive fatigue failure of the coupling discs, caused by extensive fretting on the faces and in the holes of the flexible coupling discs. If this unsafe condition develops on both the LH and RH MGB inputs, a complete power loss to the transmission could occur, resulting in subsequent loss of control of the helicopter. \n\nActions and Compliance \n\n\t(e) Required as indicated, unless previously accomplished. \n\t(1) For MGB input flexible coupling flange assemblies with less than 50 hours time-in-service (TIS) since new or since a complete overhaul of the MGB, re-adjust the tightening torque load of the 6 nuts on the flexible coupling-to-flange attachment bolts. Accomplish this re-adjustment between 50 hours TIS and 75 hours TIS since new or since a complete overhaul of the MGB in accordance with paragraph 2.B.2.a. of Eurocopter Emergency Alert ServiceBulletin No. 05.95, dated March 3, 2008 (EASB). \n\t(2) For MGB input flexible coupling flange assemblies with 50 hours TIS and 75 or less hours TIS since new or since a complete overhaul of the MGB, either: \n\t(i) Upon or before reaching 75 hours TIS since new or since a complete overhaul of the MGB, re-adjust the tightening torque load of the 6 nuts on the flexible coupling-to-flange attachment bolts in accordance with paragraph 2.B.2.a. of the EASB; or \n\t(ii) Upon or before reaching 125 hours TIS since new or since a complete overhaul of the MGB, inspect the tightening torque load of the 6 nuts on the flexible coupling-to-flange attachment bolts in accordance with paragraph 2.B.2.b. of the EASB, except you are not required to contact the manufacturer. \n\t(3) For MGB input flexible coupling flange assemblies that have more than 75 hours TIS since new or since a complete overhaul of the MGB, within the next 50 hours TIS, inspect the tightening torque load of the 6 nuts on the flexiblecoupling-to-flange attachment bolts, in accordance with paragraph 2.B.2.b. of the EASB, except you are not required to contact the manufacturer. \n\t(4) Prior to installing a MGB that contains an input flexible coupling flange assembly that has been modified per MOD 0752416 and MOD 0752419, you must comply with the provisions of this AD. \n\nDifferences Between This AD and the MCAI AD \n\n\t(f) The MCAI AD uses the term "flight hours'' instead of "hours time-in-service'', as we have used in this AD. Also, the MCAI AD allows "use of later approved revisions'' of the service information to comply with the MCAI AD. Our AD requires compliance in accordance with Eurocopter Emergency Alert Service Bulletin No. 05.95, dated March 3, 2008. Additionally, this AD requires "inspections'' by a qualified mechanic instead of "checks'', which we allow a pilot to do. Finally, this AD does not require you to contact Eurocopter Technical Support, which is required by the MCAI AD. \n\nOther Information(g) Alternative Methods of Compliance (AMOCs): The Manager, Safety Management Group, Attn: DOT/FAA Southwest Region, Ed Cuevas, Aerospace Engineer, Rotorcraft Directorate, 2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222-5355, fax (817) 222-5961, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. \n\t(h) European Aviation Safety Agency MCAI Airworthiness Directive No. 2009-0049-E, dated March 3, 2008 (Corrected: March 7, 2008), contains related information. \n\nJoint Aircraft System/Component Code \n\n\t(i) JASC Code 6310: Engine/Transmission Coupling. \n\nMaterial Incorporated by Reference \n\n\t(j) You must use the specified portions of Eurocopter Emergency Alert Service Bulletin No. 05.95, dated March 3, 2008, to do the actions required. \n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) For service information identified in this AD, contact American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, TX 75053-4005, telephone (800) 232-0323, fax (972) 641-3710, or at http://www.eurocopter.com. \n\t(3) You may review copies at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Fort Worth, Texas 76137; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/ federal-register/cfr/ibr-locations.html.