COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes AD/DHC-8/35 Amdt 1 Engine Nacelle 6/95 Applicability: Model DHC-8 Series 100 and 300 aircraft, with serial numbers as indicated in the Requirement section of this Directive. Requirement: 1. For aircraft serial numbers 3 through 137, install Modification 8/1126 (Nacelles- Sealing of Lower Cowl Firewall). De Havilland SB 8-54-12 refers. 2. For aircraft serial numbers 3 through 331, install Modification 8/1885 (Nacelle- Upper Structure Access Panel Sealing). De Havilland SB 8-54-25 refers. 3. For aircraft serial numbers 3 through 332, install Modification 8/1887 (Nacelles/Pylons - Firewall - Improvements to Fireproof and Leakproof Integrity). De Havilland SB 8-54-30 Revision B refers. 4. For aircraft serial numbers 3 through 357, install Modification 8/1966 (Nacelles/Pylons - Firewall - Addition of Sealant). De Havilland SB 8-54-31 refers. 5. For aircraft serial numbers 3 through 369, install Modification 8/2001 (Nacelles/Pylons - Cowl Door Seal Improvement). De Havilland SB 8-71-19 Revision B refers. Note: Transport Canada AD CF-94-10R1 refers. Compliance: Unless already accomplished, prior to 31 August 1995. Background: Three incidents of DHC-8 nacelle fuel leaks have resulted in an explosive ignition with subsequent damage to the engine cowling. Transport Canada requires incorporation of certain modifications which are designed to minimise the chance of a nacelle fire, through better sealing in the engine nacelle area. Amendment 1 is issued in response to a revision of the related Transport Canada AD which extends the applicability and references a later revision of the document for Requirement 5.