COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bell Helicopter Textron 412 Series Helicopters AD/BELL 412/9 Amdt 1 Main Rotor Blade Pitch Horns - Inspection 2/85 Applicability: All models fitted with main rotor pitch horn P/N 412-010-149-105 and pins P/N 412- 010-180-101. Document: Bell Alert Service Bulletin 412-83-13. Compliance: Part 1 - At the next 20 hour inspection after 12 September 1983 and each 20 hour inspection thereafter. Part 2 - Each time the pitch horn is removed. Background: The manufacturer has introduced a new horn configuration with improved corrosion protection. This directive has been amended to limit the requirement for repetitive inspections to aircraft fitted with the older design pitch horns and pins. Bell Alert SB No. 412-84-18 refers.