COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters AD/BELL 206/142 Tailboom Assembly 13/98 Applicability: BHTC Model 206L series helicopters as indicated below in the Requirement part of this directive. Tailboom assemblies modified in accordance with Technical Bulletin (TB) 206L-96-191, or BHT-206-SRM-1, section 6-3-4, with upper tailboom skin part number (P/N) 206-033-004-155 installed, are not affected by this directive. Requirement: To ensure the structural integrity of affected tailbooms, accomplish the following as applicable: Part 1. Applies to Model 206L series helicopters, serial number (S/N) 45001 through 51283, having unmodified tailboom assemblies P/N 206-033-004- 003, -011, -045, and -103. Modify the tailboom between boom station BS 151.15 and 159.35 by installing doubler P/N 206-704-167-111 with clip P/N 206-033-407-119, and re-identify the tailboom by adding the suffix "FM" to the original part number as outlined in Part I of Alert Service Bulletin (ASB) 206L-87-47 Revision C. Part 2. Applies to the following Model 206L series helicopters: Model 206L S/N 45003 through 45153, and 46601 through 46617, Model 206L-1 S/N 45154 through 45790, and Model 206L-3 S/N 51001 through 51283; having tailboom assemblies of the following part numbers: 206-033-004-003FM, -003FM1 206-033-004-011FM, -011FM1, -011FM2, -011FM3 206-033-004-103FM, -103FM1 206-033-004-045FM 1. For tailbooms with a sheet metal tail rotor gearbox support, perform an Eddy Current inspection as in Part I of ASB 206L-97-107 Revision A. b. For tailbooms with a cast tail rotor gearbox support P/N 206-033-426-001 and that do not have upper skin P/N 206-033-004-155 installed; install nutplate assemblies as per Part II of ASB 206L-97-107 Revision A. For all Model 206L helicopters affected by Parts 1 and 2 above, replacement of the tailboom with any tailboom listed below constitutes terminating action for the requirements of Parts 1 and 2 of this directive: 206-033-004-003FM2 206-033-004-011FM4 206-033-004-103FM2 COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES 206-033-004-045FM1, -045FM2 206-033-004-143, -143FM1 206-033-004-175, -175FM1 206-033-004-177 Note: Transport Canada AD CF-98-27 refers. Compliance: Part 1. Within 200 hours time in service after 3 December 1998, but not later than 31 May 1999. Part 2.a. Within 100 hours time in service after 3 December 1998, and thereafter at intervals not to exceed 1,000 hours time in service. 2.b. Within 200 hours time in service after 3 December 1998, but not later than 31 May 1999. This Airworthiness Directive becomes effective on 3 December 1998. Background: Cracking has been reported on tailbooms of earlier designs. If left undetected, these cracks could lead to failure of the tailboom and loss of control of the helicopter.