COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 727 Series Aeroplanes AD/B727/145 Lavatory Drain System 2/95 Applicability: All model 727 series aircraft. Requirement: Action in accordance with the technical requirements of FAA AD 94-23-10 Amdt 39- 9073. Note: FAA AD 94-23-10 Amdt 39-9073 supersedes FAA AD 86-05-07 Amdt 39-5250. Compliance: As specified in the Requirement Document with a revised effective date of 2 February 1995. Background: This Directive has been raised to prevent engine damage or separation, airframe damage, and/or hazard to persons or property on the ground which could occur if "blue ice" has formed from leakage of the lavatory drain system and is subsequently dislodged from the aircraft.