Summary
We propose to supersede an existing airworthiness directive (AD) that applies to all GE CF6-80C2B series turbofan engines. The existing AD currently requires installing software version 8.2.Q1 to the engine electronic control unit (ECU), which increases the engine's margin to flameout. Since we issued that AD, we have received reports of additional engine events. This proposed AD would require the removal of the affected ECUs from service. We are proposing this AD to prevent engine flameout or un-commanded engine in-flight shutdown (IFSD) of one or more engines, leading to an emergency or forced landing of the airplane.