AD 97-25-08

This amendment adopts a new airworthiness directive (AD) that is applicable to General Electric Company (GE) CJ610 series turbojet and CF700 series turbofan engines. This action requires removal from service of possibly defective turbine torque rings and compressor drive shafts which may have been manufactured from contaminated material; and replacement with serviceable parts. This amendment is prompted by a report of a cooling plate removed from a GE CT58 series engine that was found to have an iron-rich inclusion that came from a contaminated heat lot. Parts on GE CJ610 series and CF700 series engines which were manufactured from the same and similar heat lots may also be contaminated. The actions specified in this AD are intended to prevent turbine torque ring or compressor drive shaft failure due to a manufacturing defect, which could result in an uncontained engine failure.

Final rule; request for comments.

97-25-08 General Electric Company: Amendment 39-10232. Docket 97-ANE-21.
Applicability: General Electric Company (GE) CJ610 series turbojet and CF700 series turbofan engines, with turbine torque rings and compressor drive shafts identified in GE CF700 Service Bulletin (SB) No. A72-155, dated May 22, 1997, and GE CJ610 SB No. A72-147, dated May 22, 1997. These engines are installed on but not limited to the following aircraft: Learjet 20 series, Israel Aircraft Industries Westwind series, Hansa Jet, Aero Commander Jet Commander, Dassault Falcon 20 series, Sabreliner 265 series.
Note 1: This airworthiness directive (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: Required as indicated, unless accomplished previously.
To prevent turbine torque ring or compressor drive shaft failure due to a manufacturing defect, which could result in an uncontained engine failure, accomplish the following:
(a) For GE CF700 series turbofan engines, accomplish the following in accordance with GE CF700 SB No. A72-155, dated May 22, 1997:
(1) Remove from service affected turbine torque rings, listed by serial number (S/N) in paragraph 1.A. (3a) of GE CF700 SB No. A72-155, dated May 22, 1997, and replace with serviceable parts, within 50 hours time in service (TIS), or 60 days after the effective date of this AD, whichever occurs first.
(2) Remove from service affected turbine torque rings and compressor drive shafts, listed by S/N in paragraph 1.A (3b) of GE CF700 SB No. A72-155, dated May 22, 1997, and replace with serviceable parts, within 300 hours TIS, or 12 months after the effective date of this AD, whichever occurs first.
(b) For GE CJ610 series turbojet engines, accomplish the following in accordance with GE CJ610 SB No. A72-147, dated May 22, 1997:
(1) Remove from service affected turbine torque rings, listed by S/N in paragraph 1.A. (3a) of GE CJ610 SB No. A72-147, dated May 22, 1997, and replace with serviceable parts, within 50 hours TIS, or 60 days after the effective date of this AD, whichever occurs first.
(2) Remove from service affected turbine torque rings and compressor drive shafts, listed by S/N in paragraph 1.A. (3b) of GE CJ610 SB No. A72-147, dated May 22, 1997, and replace with serviceable parts, within 300 hours TIS, or 12 months after the effective date of this AD, whichever occurs first.
(c) After the effective date of this AD, installation of uninstalled affected parts identified by S/N in the SBs referenced in paragraphs (a) and (b) of this AD is prohibited.
(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, Engine Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine 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 Engine Certification Office.
(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location wherethe requirements of this AD can be accomplished.
(f) The actions required by this AD shall be done in accordance with the following GE service documents:

Document No.
Pages
Date
CF700 SB No. A72-155
1-9
May 22, 1997
Total Pages: 9.

CJ610 SB No. A72-147
1-9
May 22, 1997
Total Pages: 9.

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 GE Aircraft Engines, 1000 Western Ave., Lynn, MA 01910; telephone (781) 594-3140, fax (781) 594-4805. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief 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.
(g) This amendment becomes effective on January 2, 1998.

The Federal Aviation Administration received a report that certain turbine torque rings and compressor drive shafts installed on General Electric Company (GE) CJ610 series turbojet and CF700 series turbofan engines were forged with a contaminated alloy that could reduce the life of the part. The FAA has determined that certain heat lots of A286 material were produced with iron-rich inclusions during the vendor's normal Vacuum Induction Melt (VIM) process. The manufacturer discovered a cooling plate removed from a GE CT58 series turboprop engine had been manufactured from this heat lot and was found with an inclusion. This heat lot was also used to manufacture turbine torque rings and compressor drive shafts on GE CJ610 series turbojet and CF700 series turbofan engines. This condition, if not corrected, could result in turbine torque ring or compressor drive shaft failure due to a manufacturing defect, which could result in an uncontained engine failure.The FAA has reviewed and approved the technical contents of GE CF700 Service Bulletin (SB) No. A72-155, dated May 22, 1997, and GE CJ610 SB No. A72-147, dated May 22, 1997, that describes procedures for removing affected turbine torque rings and compressor drive shafts from service, and replacing with serviceable parts.
Since an unsafe condition has been identified that is likely to exist or develop on other engines of the same type design, this AD is being issued to prevent an uncontained engine failure and damage to the aircraft. This AD requires removing affected turbine torque rings and compressor drive shafts from service, and replacing with serviceable parts. The actions are required to be accomplished in accordance with the SBs described previously.
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental,and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 97-ANE-21-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant tothe authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: