COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Turbomeca Turbine Engines - Arriel Series AD/ARRIEL/9 Overspeed Sensor 4/95 Applicability: Arriel 1A, 1A1 engines not incorporating modification TU 13, plus Arriel 1A2, 1C, 1C1, 1C2, 1E, 1E2, 1K, 1K1, 1S and 1S1 engines. Requirement: Carry out a check of the power turbine overspeed sensor in accordance with Turbomeca Arriel Service Bulletin 292-77-0194 Revision 1. Note: DGAC Airworthiness Directive 94-218(B) refers. Compliance: Prior to 30 April 1995. Background: This Directive requires a once only check of the overspeed detector sensor to establish correct electrical connection. The requirement follows advice of a reversed connection between the two coils of the free power turbine overspeed sensor and the connector linking the sensor to the helicopter electrical harness. s