EASA 2023-0222-E

Emergency AD requires repetitive inspections of the swashplate bearing and repetitive analyses of the data extracted from the vibration health monitoring (VHM) system of the swashplate bearing. This AD also includes additional requirements for swashplate bearing geasing. EASA called the AD an interim action, indicating further steps may be forthcoming. The AD stems from several occurrences of premature in-service degradation of the swashplate bearing of H160-B helicopters. In one case, the use of the wrong grease or the mixing of incompatible greases might have initiated the degradation. VHM of the swashplate bearing has been as effective as other inspections to detect an early degradation of the swashplate bearings, however, the reliability of the VHM itself has not yet been demonstrated to be sufficient unless additional precautions are taken.