Airworthiness Directive · Amendment 39-21900 · Turbine engine accessory drive
CFM International, S.A. Turbofan Engines
This AD applies to CFM International, S.A. CFM56-3 and CFM56-7B model turbofan engines equipped with an accessory gearbox (AGB) assembly with the following part numbers (P/Ns):
(1) For CFM56-3, CFM56-3B, and CFM56-3C model turbofan engines, AGB P/N: 335- 300-103-0, 335-300-105-0, 335-300-106-0, 335-300-107-0, 335-300-108-0, 335-300-109-0, or 335-300-110-0, installed.
(2) For CFM56-7B20, CFM56-7B20/2, CFM56-7B20/3, CFM56-7B22, CFM56-7B22/2, CFM56-7B22/3, CFM56-7B22/3B1, CFM56-7B22/B1, CFM56-7B24, CFM56-7B24/2, CFM56-7B24/3, CFM56-7B24/3B1, CFM56-7B24/B1, CFM56-7B26, CFM56-7B26/2, CFM56-7B26/3, CFM56-7B26/3B1, CFM56-7B26/3B2, CFM56-7B26/3B2F, CFM56-7B26/3F, CFM56-7B26/B1, CFM56-7B26/B2, CFM56-7B27, CFM56-7B27/2, CFM56-7B27/3, CFM56-7B27/3B1, CFM56-7B27/3B1F, CFM56-7B27/3B3, CFM56-7B27/3F, CFM56-7B27/B1, and CFM56-7B27/B3 model turbofan engines, AGB P/N: 340-046-503-0, 340-046-504-0, or 340-046-505-0, installed.
(3) For CFM56-7B27A, CFM56-7B27A/3, or CFM56-7B27AE model turbofan engines, AGB P/N: 340-188-601-0, 340-188-603-0, or 340-188-605-0, installed.
The FAA is correcting an airworthiness directive (AD) that published in the Federal Register. The AD applies to CFM International, S.A. CFM56-3 and CFM56-7B model turbofan engines with certain accessory gearbox assembly (AGB) not equipped with a dynamic oil seal assembly in the handcranking pad. As published, the part numbers (P/Ns) listed in paragraph (i)(2)(i) are incorrect. This document corrects that error. In all other respects, the original document remains the same; however, for clarity, the FAA is publishing the entire rule in the Federal Register.
(1) After the effective date of this AD, after any maintenance that involves removal and re-installation of the AGB handcranking pad cover, perform an independent inspection to verify re-installation of the AGB handcranking pad cover; or
(2) Prior to the next removal of the AGB handcranking pad cover from the engine, insert the independent inspection required by paragraph (g)(1) of this AD as a required inspection item in the existing approved continuous airworthiness maintenance program for the aircraft.
As a mandatory terminating action to the requirements of paragraph (g) of this AD:
(1) For affected CFM56-3, CFM56-3B, and CFM56-3C model turbofan engines, at the next engine shop visit, or before December 31, 2026, whichever occurs first after the effective date of this AD, replace the affected AGB with a part eligible for installation.
(2) For affected CFM56-7B model turbofan engines, except for CFM56-7B27A, CFM56-7B27A/3, and CFM56-7B27AE model turbofan engines, at the next engine shop visit, or before December 31, 2024, whichever occurs first after the effective date of this AD, replace the affected AGB with a part eligible for installation.
(1) For the purpose of this AD, an “engine shop visit” is the induction of an engine into the shop for maintenance involving the separation of pairs of major mating engine case flanges, except for the following situations, which do not constitute an engine shop visit:
(i) Separation of engine flanges solely for the purposes of transportation of the engine without subsequent maintenance; or
(ii) Separation of engine flanges solely for the purpose of replacing the fan or propulsor without subsequent maintenance.
(2) For the purpose of this AD, for affected CFM56-3, CFM56-3B, and CFM56-3C model turbofan engines, a part eligible for installation is:
(i) An AGB with a P/N other than 335-300-103-0, 335-300-105-0, 335-300-106-0, 335-300-107-0, 335-300-108-0, 335-300-109-0, 335-300-110-0; or
(ii) An AGB that, using an FAA-approved procedure, has been re-worked with a dynamic oil seal in the handcranking pad cover assembly and re-identified with a new P/N not listed in paragraph (i)(2)(i) of this AD.
Note 1 to paragraph (i)(2)(ii): Procedures to install a dynamic oil seal in the handcranking pad cover assembly can be found in CFM International SB CFM56-3S/B 72-1129, Revision 7, dated May 6, 2020.
(3) For the purpose of this AD, for affected CFM56-7B model turbofan engines, except for CFM56-7B27A, CFM56-7B27A/3, and CFM56-7B27AE model turbofan engines, a part eligible for installation is:
(i) An AGB with a P/N other than 340-046-503-0, 340-046-504-0, or 340-046-505-0; or
(ii) An affected AGB that, using an FAA-approved procedure, has been re-worked with a dynamic oil seal in the handcranking pad cover assembly and re-identified with a new P/N not listed in paragraph (i)(3)(i) of this AD.
Note 2 to paragraph (i)(3)(ii): Procedures to install a dynamic oil seal in the handcranking pad cover assembly can be found in CFM International SB CFM56-7BS/B 72-0879, Revision 7, dated February 10, 2021, CFM56-7B S/B 72-0564, Revision 9, dated December 3, 2021, or CFM56-7B S/B 72-1071, initial issue, dated December 3, 2021.
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.
