COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 727 Series Aeroplanes AD/B727/163 Lower Fuselage Skin Panels 13/99 Applicability: Model 727-100 and -100C aircraft, with line numbers listed in FAA AD 99-21-10 applicability. Requirement: Replace the skin panels of the lower fuselage between body station (BS) 950 and BS1183 with non-bonded skin panels, in accordance with Part IV of the Accomplishment Instructions of Boeing Service Bulletin (SB) 727-53-0085 Revision 4, dated July 11, 1991. Note 1: Accomplishment of the modification specified in SB 727-53-0085, Revision 2, or Revision 3, is acceptable for compliance with the replacement required by this Directive. Note 2: Accomplishment of the modifications specified in the Requirement of this Directive constitutes terminating action for the inspection requirements of FAA AD 92-19-10 (AD/B727/127 Amdt 1), for those panels. Note 3: FAA AD 99-21-10 Amdt 39-11353 refers. Compliance: Within 20 years since original installation, or within 4 years after 30 December 1999, whichever occurs later. This Airworthiness Directive becomes effective on 30 December 1999. Background: The FAA received reports of corrosion of the skin panels of the lower fuselage on aircraft with hot-bonded doublers. The actions specified by this Directive are intended to prevent degradation of the structural integrity of certain skin panels of the lower fuselage, which could result in loss of aircraft pressurisation.