COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Allison Turbine Engines - 250 Series AD/AL 250/63 Amdt 7 Turbine to Compressor Coupling Shaft Inspection and Modifications to Prevent Failure 3/86 Applicability: Model 250-C30 and -C30S engines installed in Sikorsky S-76 helicopters and Model 250-C30, -C30P, -C30R and - C30S engines installed in helicopters other than Sikorsky S-76, whose engine and turbine S/N are listed in the Requirement Document excepting those engines which incorporate all of the following CEBs:- CEB-A-72- 3134 Rev. 2 or CEB-A-72-3135 Rev.1: CEB-72-3100 Rev.1: CEB-72-3059 Rev. 4 and CEB-72-3096 Rev. 1. Requirement: F.A.A. A.D. 84-24-54 R.2 Amendment 39-5163 as amended by 39-5192. Note: Allison CEB-A-72-3134 Rev. 2. CEB-A-72-3135 Rev. 1. CEB-72-3100 Rev. 1. CEB-72-3059 Rev. 4. CEB-A-72-3108 Rev. 3. CEB-72-3096 Rev.1. and CEB-A-72-3143 refer. Compliance: As detailed in the Requirement Document. Note: Compliance with the previous issue of this Directive may not satisfy the mandatory introduction of some CEBs which were previously assessed as non mandatory, hence, further rework may be necessary. Background: This Directive is amended to reflect FAA AD 84-24-54 R.2 Amdt 39-5163 as amended by 39-5192 as the Requirement Document. The FAA AD includes additional C-30 model engines in the applicability for installations other than S-76 and, requires the mandatory introduction of turbine to compressor coupling shaft associated CEBs to prevent coupling shaft distress and the possibility of shaft disconnect which could result in an uncontained turbine failure. Note: This Directive limits the use of shafts P/N 6896895 and 6889071 as temporary alternatives (pending the change to new shaft P/N 23032345) until 30 Nov 1986 for S- 76 installations and 30 Nov 1987 for other helicopter installations.