4-Sep-2020 Source: EASA
One occurrence has been reported of failure of both inverters in flight, leading to autopilot disconnection. Subsequent inspection identified chafing of a wire in the AC power system cable assembly, due to a protective grommet not correctly installed in the emergency bus interlock compartment.
This condition, if not detected and corrected, could lead to autopilot failure and possibly loss of other avionics systems, resulting in increased pilot workload and reduced control of the helicopter.