COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bell Helicopter Textron Canada (BHTC) 222 Series Helicopters AD/BELL 222/17 Drive Train Overheat Temperature Indicators 6/94 Applicability: Models 222, 222B and 222U, all serial numbers. Requirement: On all appropriate grease lubricated couplings, replace the zinc chromate type stripes with TEMP-PLATES in accordance with Part I of Bell ASB 222-93-67 Rev.A or 222U-93-40 Rev.A, as applicable. Note: Canadian AD CF-94-06 BELL refers. Compliance: At the next scheduled lubrication interval after 26 May 1994, and prior to installation of replacement couplings and/or driveshaft assemblies. Background: Following an accident with a Bell 212 it was determined that the colour change in the chromate based primers applied to couplings, was not sufficiently distinct to warn of an overheated condition and subsequent impending failure. Federal Register of Legislative Instruments F2006B04608