COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bell Helicopter Textron Canada (BHTC) 222 Series Helicopters AD/BELL 222/20 Main Rotor Grip and Flapping Bearing Assembly Applicability: All BHTC Model 222, 222B, and 222U helicopters. 11/98 TX Requirement: 1. Visually inspect the main rotor hub for obvious signs of fretting between the pitch horn and grip tangs; and between the flapping bearing assemblies and the main rotor yoke assembly. Note 1: For mechanical and corrosion limits refer to Bell Component Repair and Overhaul Manual, Volume 2. 2. Verify the torque of the retaining bolts on the main rotor grips and flapping bearing assemblies as instructed in Part I, Initial Inspection of Bell Alert Service Bulletin 222-98-81 or 222U-98-52, as applicable. If any bolt moves before the torque of 100 foot pounds (136 Nm) is reached, before further flight, remove the pitch horn or flapping bearing, as applicable, for further inspection and possible repair. Re-apply corrosion preventive compound (C-101) MIL-C-16173, Grade 1 to the exposed portions of the bolts and nuts. Note 2: Transport Canada AD CF-98-16 refers. Compliance: Unless already accomplished, within 10 hours time in service after 7 August 1998. This airworthiness directive becomes effective on 7 August 1998. Background: Fatigue cracks at the bolt holes of the main rotor pitch horn, part number 222-011- 104-101, were reported. Also, the same main rotor hub assembly had a fatigue crack in the flapping bearing assembly, part number 222-310-114-111. The cracks were found to have originated at fretting points due to loss of torque on the bolts.