Airworthiness Directive · Amendment 39-19660 · Turbine section
CFM International S.A. Turbofan Engines
Superseded. A later AD replaced this one: AD 2021-16-08. Comply with the one in force.
This AD applies to:
(1) CFM International S.A. (CFM) CFM56-5B1, -5B2, -5B4, -5B5, -5B6, -5B7, -5B1/P, -5B2/P, -5B3/P, -5B4/P, -5B5/P, -5B6/P, -5B7/P, -5B8/P, -5B9/P, -5B3/P1, -5B4/P1, -5B1/2P, -5B2/2P, -5B3/2P, -5B4/2P, -5B6/2P, -5B9/2P, -5B3/2P1, -5B4/2P1, -7B20, -7B22, -7B24, -7B26, -7B27, -7B22/B1, -7B24/B1, -7B26/B1, -7B26/B2, -7B27/B1, -7B27/B3, -7B20/2, -7B22/2, -7B24/2, -7B26/2, -7B27/2, -7B27A model turbofan engines with a:
(i) rotating air high-pressure turbine (HPT) front seal:
(A) with part number (P/N) 1795M36P01 or P/N 1795M36P02 and serial numbers (S/Ns) GWNDN949 through GWNSE969 or S/Ns GWN000CE through GWN0990L, not including S/Ns GWN08ND7, GWN0923A, GWN0971E, GWN098A1, GWN098W6, GWN098W8, GWN098WA, and GWN0990G, installed;
(B) that has been removed from the original HPT disk and re-assembled to a different HPT disk; and
(C) that has 6,001 or more cycles since being reconfigured.
(ii) [Reserved]
(2) CFM CFM56-5C2, -5C2/4, -5C2/F, -5C2/F4, -5C2/G, -5C2/G4, -5C2/P, -5C3/F, -5C3/F4, -5C3/G, -5C3/G4, -5C3/P, -5C4, -5C4/1, -5C4/P, -5C4/1P model turbofan engines with a:
(i) rotating air HPT front seal:
(A) with P/N 1795M36P01 or P/N 1795M36P02 and S/Ns GWNDN949 through GWNSE969 or S/Ns GWN000CE through GWN0990L, not including S/Ns GWN08ND7, GWN0923A, GWN0971E, GWN098A1, GWN098W6, GWN098W8, GWN098WA, and GWN0990G, installed;
(B) that has been removed from the original HPT disk and re-assembled to a different HPT disk; and
(C) that has 3,751 or more cycles since being reconfigured.
(ii) [Reserved]
The FAA is adopting a new airworthiness directive (AD) for certain CFM International S.A. (CFM) CFM56-5B, CFM56-5C, and CFM56-7B model turbofan engines with a certain rotating air high-pressure turbine (HPT) front seal. This AD requires replacement of the affected rotating air HPT front seal with a part eligible for installation. This AD was prompted by cracks found in the rotating air HPT front seal. The FAA is issuing this AD to address the unsafe condition on these products.
(1) For all affected CFM CFM56-5B and CFM56-7B model turbofan engines:
(i) If, on the effective date of this AD, the rotating air HPT front seal has 7,000 cycles or greater since being reconfigured, remove the part from service within 50 cycles after the effective date of this AD and replace with a part eligible for installation.
(ii) If, on the effective date of this AD, the rotating air HPT front seal has between 6,001 and 6,999 cycles, inclusive, since being reconfigured, remove the part from service within 500 cycles after the effective date of this AD, but not to exceed 7,050 cycles since being reconfigured, and replace with a part eligible for installation.
(2) For all affected CFM CFM56-5C model turbofan engines:
(i) If, on the effective date of this AD, the rotating air HPT front seal has 4,250 cycles or greater since being reconfigured, remove the part from service within 25 cycles after the effective date of this AD, or within 1,500 cycles since the last fluorescent penetrant inspection (FPI) of the rotating air HPT front seal, whichever occurs later, and replace with a part eligible for installation.
(ii) If, on the effective date of this AD, the rotating air HPT front seal has between 3,751 and 4,249 cycles, inclusive, since being reconfigured, remove the part from service within 250 cycles after the effective date of this AD, before accumulating 4,275 cycles since being reconfigured, or within 1,500 cycles since the last FPI of the rotating air HPT front seal, whichever occurs later, and replace with a part eligible for installation.
For the purpose of this AD, reconfigured is when a rotating air HPT front seal has been removed from the original HPT disk and re-assembled to a different HPT disk.
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.
