COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DHC-6 (Twin Otter) Series Aeroplanes AD/DHC-6/52 Windscreen Washer/De-Icing System - Discontinued Use of Isopropyl Alcohol 10/82 Applicability: All DHC-6 aircraft incorporating windscreen washer/ de-icing system using isopropyl alcohol. Requirement: 1. The use of 50/50 mixture or 100 percent isopropyl alcohol to be discontinued for the windscreen washer/de-icing system. 2. Only proprietary type fluids such as those specified in De Havilland of Canada SB 6/422, or as otherwise approved by the Department of Aviation shall be used. 3. Removal of label located above windscreen washer/de-icing system reservoir which indicates filling requirements using isopropyl alcohol. Note: Canadian Airworthiness Directive No. CF-82-20 refers. Effective: Forthwith. Background: An in-flight fire may have been caused by a faulty connection in the windscreen washer/de-icing system which allowed isopropyl alcohol to escape into the flight compartment area.