2002-01-02: Main Fuel Injectors

2002-01-02 Turbomeca S.A.: Amendment 39-12593. Docket 2001-NE-41-AD. Applicability This airworthiness directive (AD) is applicable to Turbomeca S.A. Arrius 1A turboshaft engines installed on, but not limited to Eurocopter helicopters: Model AS355N, called the Ecureuil/Twinstar; and Model AS555UN, called the Fennic. Note 1: This AD applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance Compliance with this AD is required as indicated, unless already done. To prevent blocked main fuel injectors that could lead to engine flameout during engine deceleration or that could prevent the engine from obtaining the 2-1/2 minute one engine inoperative (OEI) power, replace the 10 main fuel injectors in Arrius 1A engines with new or overhauled injectors using the following schedule: Replacement Schedule (a) Before further flight, replace any fuel injector that has accumulated more than 1,350 hours of operation since new or last overhaul. (b) Fuel injectors that have accumulated less than 1,350 hours of operation since new or last overhaul must be replaced prior to achieving 1,350 hours of operation. Service Documents for Reference (c) Turbomeca S.A. (Group Snecma) Alert Service Bulletin (ASB) No. A319 73 0071, dated January 1, 2001, contains additional information concerning the replacement of these injectors. Alternative Methods of Compliance (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Boston Engine Certification Office (ECO). Operators must submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Boston ECO. Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Boston ECO. Special Flight Permits Prohibited (e) Special flight permits are prohibited because fuel injector operation in excess of 1,350 hours is prohibited. However, operators can easily replace the fuel injectors at any location using standard maintenance tools. Note 3: The subject of this AD is addressed in Direction Generale De L'Aviation Civile (DGAC) airworthinessdirective AD Number 2000-532(A), dated December 27, 2000. Effective Date (f) This amendment becomes effective on January 22, 2002.