CTHIn ForceLegislation
AD/CFM56/27 - Low Pressure Turbine Rear Frame Life - 5 Series Engines
CFM International Turbine Engines - CFM5CFM International Turbine Engines - CFM56 Series
Start here
Get a plain-English read of CFM International Turbine Engines - CFM5
Turn the raw legal text into a practical explanation grounded in AD/CFM56/27 - Low Pressure Turbine Rear Frame Life - 5 Series Engines.
CFM International Turbine Engines - CFM56 Series
| AD/CFM56/27 | Low Pressure Turbine Rear Frame Life - 5 Series Engines | 11/2007 DM |
|---|
| Applicability: | CFM International (CFM) Model CFM56-5B1/P, -5B2/P, -5B3/P, -5B3/P1,-5B4/P, -5B4/P1, -5B5/P, -5B6/P, -5B7/P, -5B8/P and -5B9/P turbofan engines operating in commercial application and Model CFM56-5B6/P and -5B7/P turbofan engines operating in corporate application (conversion per SB 72-0308), if equipped with a low pressure turbine (LPT) rear frame part number (P/N) 338-171-703-0, 338-171-704-0, 338-171-705-0 or 338-171-706-0.Note 1: These engines are known to be installed on, but not limited to, Airbus A318, A319, A320 and A321 series aircraft. |
|---|---|
| Requirement: | 1. For LPT rear frame P/N 338-171-703-0, 338-171-704-0, 338-171-705-0, 338-171-706-0, comply with the LCF life limits in accordance with the chapters 05-12-04, 05-12-24 and 05-21-03 in the CFM56-5B ESM, revision 47, dated 15 January 2007, or later approved revision.2. If the number of cycles accumulated since new by a LPT rear frame P/N 338-171-703-0, 338-171-704-0, 338-171-705-0, 338-171-706-0 cannot be established, remove and replace the LPT rear frame, or perform the inspections in accordance with CFM56-5B Service Bulletin S/B 72-0620 initial issue, or later approved revision.Note 2: EASA AD 2007-0221 dated 13 August 2007 refers. |
| Compliance: | 1. Within 7 days after the effective date of this AD, unless previously accomplished.2. Within 300 cycles after the effective date of this AD. |
| This Airworthiness Directive becomes effective on 3 September 2007. | |
| Background: | Before the issue of the CFM56-5B Engine Shop Manual (ESM) Temporary Revision (TR) 05-0145, the concerned LPT rear frames were not subject to a life limit in commercial applications, and in corporate applications the CFM56-5B6/P and –5B7/P engines were life limited to 22 500 cycles. |
| Using a refined damage tolerant approach accounting for crack initiation and propagation to ensure any cracking that is present will not grow to unsafe levels; CFM has now established a low cycle fatigue (LCF) life limit for the concerned LPT rear frames. This requirement was first introduced by revision TR 05-0145 of the CFM56-5B ESM. This revision is approved by EASA and its content has been integrated in revision 47 of the CFM56-5B ESM, dated January 15, 2007.For the reason described above, this AD requires operators to revise their aircraft maintenance programs in accordance with these LCF life limits affecting new P/Ns. |
|---|