Action
Final rule.
Summary
We are superseding an existing airworthiness directive (AD) for all GE CF6-80C2B series turbofan engines. That AD currently requires installing software version 8.2.Q1 to the engine electronic control unit (ECU), which increases the engine's margin to flameout. This new AD requires the removal of the affected ECUs from service. This AD was prompted by two reports of engine flameout events during flight in inclement weather conditions, eight reports of engine in- flight shutdown (IFSD) events caused by dual-channel central processing unit (CPU) faults in the ECU, and four reports of engine flameout ground events. We are issuing this AD to prevent engine flameout or un- commanded engine IFSD of one or more engines, leading to an emergency or forced landing of the airplane.