500e,
'AVC type' devices are quite common and are not specific to the S-92. Even (Zalt) the 5-bladed EH-101 and EC225s have them. Not saying I wouldn't like 5 blades though.......
Personally I'd be surprised if this was the cause of the RTB. The system is very sensitive in detecting faults and displays either AVC FAIL or AVC DEGRD when there's a fault. The checklist response is to continue the flight - at reduced speed if necessary. It's also an MEL item and is not required for dispatch.