2001-25-05: Compressor Cone Shafts

2001-25-05 Rolls-Royce Corporation: Amendment 39-12558. Docket No. 99-NE-46-AD. Supersedes AD 2000-09-05, Amendment 39-11714. Applicability This airworthiness directive (AD) is applicable to Rolls-Royce Corporation (formerly Allison Engine Company) models AE 3007A, AE 3007A1, AE 3007A1/1, AE 3007A1/2, AE 3007A1/3, AE 3007A1P, and AE 3007C turbofan engines, with compressor cone shafts, part numbers (P/N's) 23050728 and 23070729, installed. These engines are installed on but not limited to EMBRAER EMB-135 and EMB-145 series and Cessna 750 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 (h) 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 low-cycle fatigue (LCF) failure of cone shafts, which could result in an uncontained engine failure and damage to the airplane, do the following: (a) For Rolls-Royce Corporation model AE 3007A engines, remove cone shafts from service prior to accumulating 9,500 cycles-since-new (CSN) and replace with serviceable parts. (b) For Rolls-Royce Corporation model AE 3007C engines, remove cone shafts from service prior to accumulating 14,500 CSN and replace with serviceable parts. (c) For Roll-Royce Corporation models AE 3007A1, AE 3007A1/1, and AE 3007A1/2 engines, remove cone shafts from service prior to accumulating 7,500 CSN and replace with serviceable parts. (d) For Rolls-Royce Corporation model AE 3007A1/3 engines: (1) With compressor cone shafts P/N 23070729, serial number (SN) MM78599, MM78615, MM78632, MM78650, MM78651, MM78652, MM78653, MM78654, MM78655, MM78656, MM78657, MM78658, MM78659, MM78660, MM78661, MM78662, MM78663, MM78665 or higher, remove cone shafts from service prior to accumulating 9,300 CSN and replace with serviceable parts. (2) With compressor cone shafts P/N 23050728, or P/N 23070729 having other than the S/N's listed in paragraph (d)(1) of this AD, remove cone shafts from service prior to accumulating 3,500 CSN and replace with serviceable parts. (e) For Rolls-Royce Corporation AE 3007A1P engines: (1) With compressor cone shafts P/N 23070729, SN MM78599, MM78615, MM78632, MM78650, MM78651, MM78652, MM78653, MM78654, MM78655, MM78656, MM78657, MM78658, MM78659, MM78660, MM78661, MM78662, MM78663, MM78665 or higher, remove cone shafts from service prior to accumulating 7,300 CSN and replace with serviceable parts. (2) With compressor cone shafts P/N 23050728, or P/N 23070729 having other than the SN's listed in paragraph (e)(1) of this AD, remove cone shafts from service prior to accumulating 2,400 CSN and replace with serviceable parts. New Life Limits (f) Paragraphs (a), (b), (c), (d) and (e) of this AD establish new, lower life limits for cone shafts, P/N's 23050728 and 23070729. (g) Except for the provisions of paragraph (h) of this AD, no cone shafts, P/Ns 23050728 and 23070729, may remain in service exceeding the life limits established in paragraphs (a), (b), (c), (d) and (e) of this AD. Alternative Methods of Compliance (h) 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 (i) Special flight permits may be issued in accordance 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 done. Effective Date (j) This amendment becomes effective on January 23, 2002.