COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES McDonnell Douglas (Hughes) and Kawasaki 369 Series Helicopters AD/HU 369/58 Main Rotor Swashplate Bearing - Inspection - Replacement 2/84 Applicability: All 500 model 369 Series Aircraft equipped with, swashplate bearing assembly 369A 7003-3 and main rotor installation 369A 1000-502 or 369D 21000 and main rotor swashplate installation 369A 7609-501, 369A 7609-605 or 369D 27609-501 installed after 1 June 1983 except those 369A 7003-3 swashplate bearing assemblies with 9xxx series serial numbers or marked with a blue lacquered dot on the outer surface of the bearing seal retention snap ring. Document: Hughes Service Information Notices HN 191, EN12 and DN-125. Compliance: Before further flight after 5th January 1984. Background: The manufacturer reports that a main rotor swashplate bearing assembly, has been found without the ball bearing cages installed, consequently a one time inspection is required to ensure correct assembly.