COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Agusta A109 Series Helicopters AD/A109/28 Tail Rotor Blade Grip Assemblies 7/97 DM Applicability: All A109C up to Serial Number 7670, excluding 7630, 7633, 7645, 7651, 7653, 7657, 7661, 7663, 7665, 7667, and 7669. Requirement: Action in accordance with Agusta Bollettino Tecnico No. 109-100, Rev A. Note: RAI AD 97-084 refers. Compliance: Before 30 June 1997. This Airworthiness Directive becomes effective on 14 May 1997. Background: Cracking has been discovered in the grip assemblies P/N 109-8131-05-109 and -113. This Directive is issued to replace the grip assemblies with an improved item and rework of the blades to accept larger diameter bolts.