Summary
The FAA proposes to adopt 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 proposed 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 proposed AD would require removal of the HMU and replacement with a part eligible for installation. The FAA is proposing this AD to address the unsafe condition on these products.