Airworthiness Directive · Amendment 39-14926 · CFM International CFM56-5 and -5B Series Turbofan Engines
CFM International CFM56-5 and -5B Series Turbofan Engines
This AD applies to CFM International CFM56-5 and -5B series turbofan engines:
(1) With an exhaust gas temperature (EGT) upper harness part number (P/N) CA170-00, with a serial number (SN):
(i) Listed in Table 1, Table 4, or Table 5 of CFM56 Service Bulletin (SB) No. CFM56-5B S/B 77-0008, Revision 3, dated April 4, 2005, or
(ii) Listed in Table 1 or Table 4 of CFM56 SB No. CFM56-5 S/B 77-0020, Revision 3, dated April 4, 2005.
(2) With an EGT lower harness P/N CA171-00, with a SN:
(i) Listed in Table 2, Table 4, or Table 5 of CFM56 SB No. CFM56-5B S/B 77-0008, Revision 3, dated April 4, 2005; or
(ii) Listed in Table 2 or Table 4 of CFM56 SB No. CFM56-5 S/B 77-0020, Revision 3, dated April 4, 2005.
(3) With an EGT coupling P/N CA172-02 with a SN:
(i) Listed in Table 3, Table 4, or Table 5 of CFM56 Service Bulletin (SB) No. CFM56-5B S/B 77-0008, Revision 3, dated April 4, 2005, or
(ii) Listed in Table 3 or Table 4 of CFM56 SB No. CFM56-5 S/B 77-0020, Revision 3, dated April 4, 2005.
(4) These engines are installed on, but not limited to Airbus Industrie A318, A319, A320, and A321 airplanes.
The FAA is superseding an existing airworthiness directive (AD) for CFM International CFM56-5 and -5B series turbofan engines. That AD requires exhaust gas temperature (EGT) harness replacement or the establishment of an EGT baseline and trend monitoring. That AD also requires replacement, if necessary, of certain EGT harnesses and EGT couplings as soon as a slow and continuous EGT drift downward is noticed after the effective date of that AD. This AD requires the same actions but for an increased population of affected EGT harnesses. This AD results from CFM International adding subsequently certified engine models to the list of engines that could have affected harnesses installed. We are issuing this AD to prevent unexpected deterioration of critical rotating engine parts due to higher than desired engine operating EGTs.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
(f) If an EGT harness or EGT coupling has a serial number that is followed by the letter “W”, no further action is required for that part.
(g) For affected EGT harnesses and EGT couplings identified using paragraph (c) of this AD, with fewer than 3,000 engine flight hours-since-installation, do the following:
(1) Replace affected EGT harnesses and EGT couplings, not being trend monitored, with serviceable parts within 500 flight hours after the effective date of this AD; or
(2) After the effective date of this AD:
(i) Review the smooth data EGT trend via the System for Analysis of Gas Turbine Engines (SAGE), or equivalent, since the affected components were first installed on the current engine.
(ii) Continue this trend monitoring for the affected EGT harnesses and EGT couplings to ensure that the system does not show a minimum of 30 °C downward (i.e. cooler) indication, or more, without a corresponding change in other associated engine parameters such as N1 (LPT rotor speed), N2 (HPT rotor speed), and fuel flow.
(iii) Provided that there is sufficient, actual EGT margin to do so, replace the EGT harnesses and EGT couplings within 100 flight hours after they have been determined to be defective.
(iv) Continue to monitor the EGT indications for 3,000 engine flight hours since the first installation on the current engine.
Any of the following three conditions is terminating action for the trend monitoring requirements specified in paragraphs (g)(2)(i) through (g)(2)(iv) of this AD:
(1) Replacing an EGT harness and EGT coupling with a serviceable part, or
(2) Replacing an EGT harness and EGT coupling with an EGT harness and EGT coupling that has a letter “W” following the SN, or
(3) Accumulating 3,000 engine flight hours on an EGT harness and EGT coupling.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
