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 250/70 No. 8 Bearing Scavenge Line Air/Oil Separator 8/86
Applicability: 250-C28B and C28C series engines with engine and turbine serial numbers listed in the Requirement Document.
Requirement: Modify the engine oil system in accordance with Allison Alert CEB-A-72-2138 dated 15 May 1986.
Compliance: Within 100 hours of engine operation after 31 August 1986 but no later than 31 January 1987.
Background: This Directive is issued to install an air/oil separator in the No. 8 bearing scavenge line to improve venting of the No. 8 bearing oil sump. Excess pressure in the No. 8 bearing sump may result in internal oil fire and cause a No. 1 turbine wheel failure.