COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 767 Series Aeroplanes AD/B767/46 Vertical Stabiliser 12/90 Applicability: Model 767 line numbers 002 through 299. Requirement: Action in accordance with Boeing Alert SB767-55A0007. Note: FAA AD 90-18-05 Amdt 39-6713 refers. Compliance: Unless previously accomplished, prior to 30 April 1992. Background: Country of origin AD. To prevent overpressurization of the vertical stabilizer, which could cause structural failure. This could happen if rapid decompression of the fuselage occurred in the stabilizer area.