Airworthiness Directive · Amendment 39-21298 · Engine fuel and control
General Electric Company Turbofan Engines
This AD applies to all General Electric Company (GE) CF6-80C2A5F, -80C2B1F, -80C2B2F, -80C2B4F, -80C2B5F, -80C2B6F, -80C2B6FA, -80C2B7F, -80C2B8F, -80C2D1F, -80C2K1F, -80C2L1F, -80E1A2, -80E1A3, -80E1A4, and -80E1A4/B model turbofan engines with a hydromechanical unit (HMU) with a part number (P/N) listed in paragraph 1.A., Table 1, of GE Service Bulletin (SB) CF6-80C2 SB 73-0436 R02, dated August 15, 2019; or paragraph 1.A., Table 1, of GE SB CF6-80E1 SB 73-0142 R02, dated August 15, 2019; installed.
The FAA is adopting a new airworthiness directive (AD) for all General Electric Company (GE) CF6-80C2A5F, -80C2B1F, -80C2B2F, - 80C2B4F, -80C2B5F, -80C2B6F, -80C2B6FA, -80C2B7F, -80C2B8F, -80C2D1F, - 80C2K1F, -80C2L1F, -80E1A2, -80E1A3, -80E1A4, and -80E1A4/B model turbofan engines with a certain hydromechanical unit (HMU) installed. This AD was prompted by a report of fuel coking of the HMU fuel metering valve (FMV) electro-hydraulic servo valves (EHSV) resulting in tailpipe fire. This AD requires removal of the HMU and its replacement with a part eligible for installation. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Remove the HMU and replace with a part eligible for installation before reaching 40,000 flight hours (FHs) since new or since the last overhaul, or within 180 days after the effective date of this AD, whichever is later. If the FHs since new or last overhaul are unknown and unable to be determined, replace the HMU with a part eligible for installation within 180 days after the effective date of this AD.
(2) Thereafter, remove the HMU before reaching 40,000 FHs since new or since the last overhaul and replace with a part eligible for installation.
(1) For the purpose of this AD, a “part eligible for installation” is an HMU that has fewer than 40,000 FHs since new or fewer than 40,000 FHs since an overhaul of the HMU.
(2) For the purpose of this AD, “an overhaul of the HMU” is one of the following:
(i) An overhaul of the HMU (complete) using Honeywell-approved maintenance procedures; or
(ii) An overhaul of the HMU FMV EHSV using the Accomplishment Instructions, paragraph 3.C.(3), of GE SB CF6-80C2 SB 73-0436 R02, dated August 15, 2019, or paragraph 3.C.(3), of GE SB CF6-80E1 SB 73-0142 R02, dated August 15, 2019.
You may take credit for the initial removal and replacement of the HMU required by paragraph (g)(1) of this AD if the HMU FMV EHSV was overhauled before the effective date of this AD using GE SB CF6-80C2 SB 73-0436 R01, dated May 14, 2019, or GE SB CF6-80C2 73-0142 R01, dated May 14, 2019.
