AD 2004-15-03R1 Airworthiness Directives; General Electric Company CF34-3A1 and -3B1 Series Turbofan Engines

This AD applies to General Electric Company (GE) CF34-3A1 and -3B1 series turbofan engines with stage 5 low pressure turbine (LPT) disks, part number (P/N) 6078T92P01, and or stage 6 LPT disks, P/N 6078T89P01, with serial numbers (SNs) listed in Figure 3 of GE Alert Service Bulletin (ASB) No. CF34-AL S/B 72-A0173, Revision 3, dated July 20, 2004. These engines are installed on, but not limited to, Bombardier Canadair CL600-2B19 (RJ) airplanes.

You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. Initial Inspection or Replacement (f) Using the compliance schedule in Table 1 of this AD: (1) Visually inspect and eddy current inspect (ECI) applicable stage 5 LPT disks and applicable stage 6 LPT disks using paragraphs 3.C.(1) through 3.E.(6) of GE ASB No. CF34-AL S/B 72-A0173, Revision 3, dated July 20, 2004, if the inspections can be completed within 9 calendar months after the effective date of this AD; or (2) If the inspections specified in paragraph (f)(1) of this AD cannot be completed within 9 calendar months after the effective date of this AD, replace applicable stage 5 LPT disks and applicable stage 6 LPT disks with a serviceable disk using the compliance schedule in Table 1 of this AD. (3) The requirements of paragraphs (f)(1) and (f)(2) of this AD do not apply if the inspections were conducted using paragraph (g)(1) of this AD. Table 1.—Compliance Schedule On the effective date of this AD, if the disk has: Then perform the actions defined in paragraph (f) of this AD at next piece-part exposure, not to exceed the accumulation of: (i) 14,750 or more cycles-since-new (CSN) and has not been fluorescent penetrant inspected (FPI) at an earlier piece-part exposure An additional 250 cycles-in-service (CIS) after the effective date of this AD. (ii) 14,750 or more CSN and has been FPI at an earlier piece-part exposure An additional 500 CIS after the effective date of this AD. (iii) 14,500 or more CSN but fewer than 14,750 CSN An additional 500 CIS after the effective date of this AD. (iv) 14,250 or more CSN but fewer than 14,500 CSN An additional 750 CIS after the effective date of this AD. (v) 13,000 or more CSN but fewer than 14,250 CSN An additional 1,000 CIS after the effective date of this AD. (vi) 2,500 or more CSN but fewer than 13,000 CSN An additional 4,000 CIS after the effective date of this AD, or 14,000 CSN, whichever comes first. (vii) Fewer than 2,500 cycles-since-new (CSN) 6,500 CSN. (g) Before installation in an airplane: (1) Visually inspect and ECI applicable stage 5 LPT disks and applicable stage 6 LPT disks installed in replacement engines or replacement LPT modules using paragraphs 3.C.(1) through 3.E.(6) of GE ASB No. CF34-AL S/B 72-A0173, Revision 3, dated July 20, 2004, if the inspections can be completed within 9 calendar months after the effective date of this AD; or (2) If the inspections specified in paragraph (g)(1) of this AD cannot be completed within 9 calendar months after the effective date of this AD, replace applicable stage 5 LPT disks and applicable stage 6 LPT disks installed in replacement engines or replacement LPT modules with a serviceable disk. Repetitive Inspections (h) For stage 5 LPT disks and stage 6 LPT disks initially inspected as specified in paragraph (f)(1) or (g)(1) of this AD, perform repetitive visual inspections and ECIs within every 3,100 cycles-since-last-inspection, using paragraphs 3.C.(1) through 3.E.(6) of GE ASB No. CF34-AL S/B 72-A0173, Revision 3, dated July 20, 2004, until the life limit of the part is reached. Disks That Pass Inspection (i) If a disk passes inspection, it must be reinstalled into the same LPT module it was removed from. Optional Terminating Action (j) Replacement of an applicable stage 5 LPT disk or applicable stage 6 LPT disk with a disk not listed in Figure 3 of GE ASB No. CF34-AL S/B 72-A0173, Revision 3, dated July 20, 2004, is terminating action to the inspections required by this AD for that disk. Actions Completed per Previous Releases of Alert Service Bulletin CF34-AL S/B 72-A0173 (k) Actions completed before the effective date of this AD using GE ASB No. CF34-AL S/B 72-A0173, dated April 2, 2004; or Revision 1, dated May 20, 2004; or Revision 2, dated June 22, 2004; or Revision 3, dated July 20, 2004; are considered acceptable for compliance with the corresponding action in this AD. Definitions (l) For the purposes of this AD, a serviceable disk is defined as a disk that has a SN not listed in Figure 3 of GE ASB No. CF34-AL S/B 72-A0173, Revision 3, dated July 20, 2004. (m) For the purposes of this AD, the definition of piece-part exposure for the stage 5 LPT disk is when the disk is separated from the forward and aft bolted joints. (n) For the purpose of this AD, the definition of piece-part exposure for the stage 6 LPT disk is when the disk is separated from the forward bolted joint. (o) For the purposes of this AD, the definition of a replacement engine or replacement LPT module is an engine or LPT module that is not installed on an operational airplane on the effective date of this AD. Alternative Methods of

This AD results from a report of a stage 5 LPT disk that failed due to cracking from low-cycle-fatigue during factory testing. The crack started at the site of an electrical arc-out.