2001-17-31: Second Stage High Pressure Turbine Wheel

2001-17-31 Rolls-Royce Corporation: Amendment 39-12423. Docket No. 2000-NE-27-AD. Applicability This airworthiness directive (AD) is applicable to Rolls-Royce Corporation (formerly Allison Engine Company) models AE 2100A and AE 2100C turboprop engines with high pressure turbine (HPT) wheel part number (P/N) 23050912 installed; AE 2100A turboprop engine with turbine wheel P/N 23063462 serial number (SN) MM14062 installed; AE 2100A, AE 2100C, AE 2100D3 turboprop and AE 3007A, and AE 3007C turbofan engines with 2nd stage HPT wheels with SN's before MM183060. These engines are installed on but not limited to Embraer EMB-145, Cessna 750, SAAB 2000, and Industi Pesawat Terbang Nusantara (IPTN) N-250 series airplanes. 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 (g) 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 detect and prevent early development of cracks due to low cycle fatigue of the 2nd stage HPT wheel in the aft bore face that can lead to wheel failure, power loss, and possible damage to the airplane, do the following: One-time Inspection (a) Perform a one-time acid etch inspection to the 2nd stage high pressure turbine wheel in accordance with the Accomplishment Instructions contained in the following Rolls-Royce Alert Service Bulletins: Table 1.--Applicable Alert Service Bulletins AE models Rolls-Royce service bulletin AE 2100A AE 2100A-A-72-234, Revision 2, dated October 13, 2000 or Revision 3, dated June 19, 2001. AE 2100C AE 2100C-A-72-183, Revision 2, dated October 13, 2000 or Revision 3, dated June 19, 2001. AE 2100D3 AE 2100D3-A-72-179, Revision 2, dated October 13, 2000 or Revision 3, dated June 19, 2001. AE 3007A AE 3007A-A-72-179, Revision 2, dated October 17, 2000 or Revision 3, dated June 19, 2001. AE 3007C AE 3007C-A-72-153, Revision 2, dated October 17, 2000 or Revision 3, dated June 19, 2001. (b) Perform these inspections according to the following compliance times: Table 2.--Inspection Compliance Times Models With turbine wheel Mandatory (1) AE 2100A, AE2100C 23050912 Before 4,800 cycles since new (CSN). (2) AE 2100A 23063462-S/N MM14062. Before 4,800 CSN. (3) AE2100D3 23050912 Before 3,200 CSN. (4) All other AE 2100A, AE 2100C and AE2100D3 23063462, 23064822, 23070673, 23065892, 23069116, 23064473, 23064474, 23068072, 23070672 and 23070675 with S/N's MM183060 and before. At next shop visit. (5) All AE 3007A, and AE 3007C 23063462, 23065892, 23069116 with S/N MM183060 and before. At next shop visit. (6) All AE 3007A and AE 3007C 23069592 with S/N MM183060 and before. At next exposure but not to exceed 12,800 CSN. (7) All AE 2100A and 23069592 AE 2100C 23069592 with S/N MM183060 and before. Next exposure but not to exceed 16,800 CSN. (8) All 2100D3 23069592 with S/N MM183060 and before. At next exposure but not to exceed 14,100 CSN. (c) If damage is discovered, replace the turbine wheel with a serviceable part. Definitions (d) The next shop visit is defined as whenever the engine is removed and sent to a maintenance center for inspection or repair. (e) A serviceable part is defined as any applicable turbine wheel with a serial number greater than MM183060, or a wheel with a serial number MM183060 or lower that has undergone an acid etch inspection with no indication of damage. (f) After the effective date of this AD, do not install any 2nd-stage gas-generator turbine wheel listed in Table 2 of this AD, unless it has been inspected as specified in paragraph (a). Alternative Methods of Compliance (g) 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, Chicago Aircraft Certification Office. Operators must submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Chicago Aircraft Certification Office. Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Chicago Aircraft Certification Office. Special Flight Permits (h) Special flight permits may be issued inaccordance Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished. Documents That Have Been Incorporated by Reference (i) The inspection must be done in accordance with the following Rolls-Royce Corporation Alert Service Bulletins: Document No. Pages Revision Date ASB AE 2100A-A-72-234 All 2 October 13, 2000. ASBAE 2100C-A-72-183 All 2 October 13, 2000. ASB AE 2100D3-A-72-179 All 2 October 13, 2000. Total Pages: 13 ASB AE 2100A-A-72-234 All 3 June 19, 2001. ASBAE 2100C-A-72-183 All 3 June 19, 2001. ASB AE 2100D3-A-72-179 All 3 June 19, 2001. Total Pages: 13 ASB AE 3007A-A-72-179 All 2 October 17, 2000. ASB AE 3007C-A-72-153 All 2 October 17, 2000. Total Pages: 12 ASB AE 3007A-A-72-179 All 3 June 19, 2001. ASB AE 3007C-A-72-153 All 3 June 19, 2001. TotalPages: 12 This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206-0420; telephone: (888) 255-4766 . Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC. Effective Date of This AD (j) This amendment becomes effective on October 5, 2001.