2004-14-02: SN third-stage turbine wheels

2004-14-02 Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison): Amendment 39-13711. Docket No. FAA-2004-18538; Directorate Identifier 2004-NE- 29-AD. Effective Date (a) This airworthiness directive (AD) becomes effective July 26, 2004. Affected ADs (b) None. Applicability (c) This AD applies to Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) models 250-C28, -C28B, and -C28C turboshaft engines with third-stage turbine wheels, part number (P/N) 6899383, listed by serial number (SN) in the following Table 1: Table 1.--SNs of Affected Third Stage Turbine Wheels HX91922 X523242 X523281 HX91923 X523243 X523283 HX91925 X523244 X523284 HX91926 X523246 X523287 HX91928 X523249 X523288 HX91929 X523250 X523289 HX91930 X523251 X523290 HX91932 X523253 X523291 HX91934 X523255 X523292HX91936 X523257 X523293 HX91937 X523260 X523294 HX91939 X523261 X523295 HX91940 X523262 X523296 HX91960 X523263 X523297 HX91962 X523264 X523298 HX91966 X523265 X523300 HX91976 X523266 X523305 HX91977 X523268 X523309 HX91979 X523269 X523313 HX91980 X523270 X523315 X523236 X523271 X523317 X523237 X523273 X523319 X523238 X523276 X523320 X523239 X523277 N/A X523241 X523278 N/A These engines are installed on, but not limited to, Bell Helicopter Textron 206L-1; Eurocopter Deutschland BO 105 LS A-1; and Eurocopter Canada BO 105 LS A-3 helicopters. Unsafe Condition (d) This AD results from three reports of third-stage turbine wheel blade and shroud failures. We are issuing this AD to prevent loss of power and uncommanded engine shutdown due to failure of the third-stage turbine wheel blade and shroud. Compliance (e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. (f) For any third-stage turbine wheel with fewer than 250 operating hours time since new (TSN) on the effective date of this AD, replace turbine wheel before accumulating 300 operating hours TSN. (g) For any third-stage turbine wheel with 250 or more operating hours TSN on the effective date of this AD, replace turbine wheel before accumulating an additional 50 operating hours. Definition (h) For the purposes of this AD, a replacement third-stage turbine wheel is a turbine wheel that does not have a SN listed in this AD. (i) After the effective date of this AD, do not install third- stage turbine wheels that are listed in Table 1 of this AD, into any engine. Alternative Methods of Compliance (j) The Manager, Chicago Aircraft Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.Special Flight Permits (k) Under 14 CFR 39.23, we are prohibiting special flight permits for this AD. Material Incorporated by Reference (l) None. Related Information (m) Rolls-Royce Corporation Alert Commercial Engine Bulletin No. CEB-A-72-2202, dated May 6, 2004, pertains to the subject of this AD.