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 412/25 Main Rotor Flight Control System Bolts 10/89
DM
Applicability: All model 412 series.
Requirement: Action in accordance with Bell Alert Service Bulletin No 412-89-45. Compliance: At next scheduled inspection for issue of a Maintenance Release after 20 August
1989, or by 20 October 1989, whichever occurs first. Thereafter, reinspect at intervals not exceeding 24 months calendar time.
Background: Bell have advised that some of the rotating control bolts have been found corroded, fretting and/or with excessive wear on the bolt shank.