the roll actuators are identical time in service they can build carbon in the motors identically and start to act up, identically, at X time. Had a roll runaway in lateral on both actuators at the cruise in an AS365 N2 due to it and an identical severe end to end yaw problem in an S76 B model. No clue if relevant to the discussion but if ya haven't heard of the reality there ya go. Not having identical component times is a big deal in ETOPS, or whatever the acronym is these days
