COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Gulfstream (Rockwell) 112 Series Aeroplanes AD/AC-112/13 Amdt 2 Wing Forward Spar 6/95 Applicability: Models 112 and 112B with serial numbers 1 to 544 and 13000, and models 112TC and 112TCA with serial numbers 13001 to 13309, not modified on both left and right hand sides in accordance with Gulfstream Aerospace Service Bulletin 112-71C Part II, Part III, Part IV or Part V. Requirement: 1. Visually inspect, using a mirror or borescope, the upper cap of the forward wing spar in the area of the main landing gear side brace fitting. Inspect in accordance with the instructions specified in Part I of Gulfstream Aerospace Service Bulletin 112-71C. 2.a. For aircraft not previously modified in accordance with either Part II or Part V of Gulfstream Aerospace SB 112-71, -71A or 71B, modify in accordance with Part II of Gulfstream Aerospace Service Bulletin 112-71C, or 2.b. For aircraft previously modified in accordance with either Parts II or Part V of Gulfstream Aerospace Service Bulletin 112-71, -71A or -71B, modify in accordance with Part III of Gulfstream Aerospace Service Bulletin 112-71C. Note: FAA AD 90-04-07 refers and supersedes FAA AD 87-14-03. Compliance: 1. Initially inspect in accordance with Requirement 1 within 25 hours' time in service from 25 May 1995. Re-inspect at intervals not to exceed 100 hours' time in service. 2. Modify in accordance with Requirement 2 within 300 hours' time in service from 25 May 1995. Aircraft modified in accordance with Gulfstream Aerospace Service Bulletin 112-71, 112-71A or 112-71B or Drawing 40002 RWK #1, #2, #4G, #4H or 42000 RWK #3 are only in partial compliance with this AD and require further inspection and modification. Background: There have been several Australian reports of cracking similar to that described in the Gulfstream SB.. The FAA have determined that the earlier modifications are inadequate as a permanent solution to the problem. This Amendment introduces the latest Revision of the SB, which requires a more extensive modification.