COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Rolls Royce Turbine Engines - RB211 Series AD/RB211/8 H.P. Compressor Rotor Stage 4 to 6 Shaft Assembly - Life Limitation 5/83 CANCELLED. Background: Extensive laboratory investigation and stress analysis has now shown that the life restriction placed upon the affected assemblies by Rolls Royce RB211 SB211-72- 6420 can be removed. They can now assume the same life as their unaffected equivalent parts.