Summary
The FAA proposes to adopt a new airworthiness directive (AD) for GE CF6-80C2D1F turbofan engines, installed on McDonnell Douglas Corporation MD-11 series airplanes. This proposed AD would require removing previous software versions from the engine electronic control unit (ECU). Engines with new version software will have increased margin to flameout. This proposed AD results from reports of engine flameout events during flight, including reports of events where all engines simultaneously experienced a flameout or other adverse operation. Although the root cause investigation is not yet complete, we believe that exposure to ice crystals during flight is associated with these flameout events. We are proposing this AD to minimize the potential of an all-engine flameout event caused by ice accretion and shedding during flight.