Airworthiness Directive · Amendment 39-21405 · Fuel control/turbine engines
General Electric Company Turbofan Engines
This AD applies to General Electric Company (GE) CF6-80C2A1, CF6-80C2A2, CF6-80C2A3, CF6-80C2A5, CF6-80C2A5F, CF6-80C2A8, CF6-80C2B1, CF6-80C2B1F, CF6-80C2B2, CF6-80C2B2F, CF6-80C2B4, CF6-80C2B4F, CF6-80C2B5F, CF6-80C2B6, CF6-80C2B6F, CF6-80C2B6FA, CF6-80C2B7F, CF6-80C2B8F, and CF6-80C2D1F model turbofan engines that underwent an engine shop visit before November 1, 2018, and with accessory gearbox (AGB) adapter hydromechanical unit (HMU)/main engine control (MEC) idler adapter with part number (P/N) 9395M78G01, P/N 9395M78G02, P/N 9395M78G04, P/N 9395M78G05, P/N 9395M78G08, or P/N 9395M78G10, installed.
The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) CF6-80C2A1, CF6-80C2A2, CF6- 80C2A3, CF6-80C2A5, CF6-80C2A5F, CF6-80C2A8, CF6-80C2B1, CF6-80C2B1F, CF6-80C2B2, CF6-80C2B2F, CF6-80C2B4, CF6-80C2B4F, CF6-80C2B5F, CF6- 80C2B6, CF6-80C2B6F, CF6-80C2B6FA, CF6-80C2B7F, CF6-80C2B8F, and CF6- 80C2D1F model turbofan engines. This AD was prompted by reports of incidents that resulted in a significant fuel loss during flight and an in-flight shutdown (IFSD) of the engine. This AD requires initial and repetitive shim checks of the hydromechanical unit/main engine control (HMU/MEC) idler adapter on the accessory gearbox (AGB) assembly and, depending on the results of the shim check, possible replacement of the inserts on the HMU/MEC idler adapter. As a terminating action, this AD requires a protrusion check and a pull-out test, and the replacement of inserts on the HMU/MEC idler adapter that fail either test. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Perform a shim check of the HMU/MEC idler adapter inserts using paragraph 3.B.(1) of GE CF6-80C2 Service Bulletin (SB) 72-1577 R01, dated August 16, 2019 (the SB), within 1,200 flight hours (FHs) after the effective date of this AD.
(2) Thereafter, perform a repetitive shim check of the HMU/MEC idler adapter inserts using paragraph 3.B.(1) of the SB within every 1,200 FHs since the last shim check.
(3) If any HMU/MEC idler adapter insert fails the shim check required by paragraph (g)(1) or (2) of this AD, perform the following before further flight:
(i) Retorque the bolts at each bolt location that failed the shim check using paragraph 3.B.(1)(c) of the SB.
(ii) Perform the shim check again using paragraph 3.B.(1)(b) of the SB. If the shim check fails, perform the terminating action required by paragraph (h) of this AD.
As a terminating action to the requirements of paragraph (g) of this AD, perform the following:
(1) Do a protrusion check at all eight bolt locations using paragraph 3.C.(3) of the SB.
(2) Do a pull-out test at all eight bolt locations using paragraph 3.C.(4) of the SB.
(3) If the inserts on the HMU/MEC idler adapter fail the protrusion check or pull-out test required by paragraph (h)(1) or (2) of this AD, replace the inserts using paragraph 3.C.(5) of the SB. After replacement of the inserts is accomplished, the requirements of this AD have been met and no further action is required.
(4) If the inserts on the HMU/MEC idler adapter pass both the protrusion check and the pull-out test required by paragraphs (h)(1) and (2) of this AD, the requirements of this AD have been met and no further action is required.
