COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES DHC-3 (Otter) Series Aeroplanes AD/DHC-3/36 Fire Detection and Extinguishing System 6/99 Applicability: All Model DHC-3 'Otter' aeroplanes powered by Pratt and Whitney reciprocating, nine cylinder, radial, air-cooled engines. Requirement: 1. Inspect the fire extinguishing system (FIREX) in accordance with the DHC-3 Maintenance Manual, PSM 1-3-2, pages 122 and 122A (revised 15 September 1963), paragraph 4.11.4. 2. If, during the Requirement 1 inspection, the FIREX is found to be unserviceable, either repair the system or replace it with a serviceable approved system. 3. Determine if the fire detection system (FIRDET) is time-expired by making reference to the appropriate Graviner Ltd literature such as Maintenance Leaflet ML 066 dated April 1981. 4. If, as a result of the Requirement 3 determination, the FIRDET is found to be time- expired, replace it with a serviceable approved system. 5. For aeroplanes that have had the FIREX and/or FIRDET removed, replace the missing system(s), as applicable, by installing an approved serviceable FIREX and/or FIRDET. Note 1: Transport Canada Civil Aviation AD CF-99-06 refers. Note 2: This Directive supersedes and cancels any approval granted by a modification approved under Civil Aviation Regulation 35 or in any Supplemental Type Certificate or equivalent document that authorises the removal of the FIREX and/or FIRDET. Compliance: 1. Within 60 days after the effective date of this Directive. 2. No later than 30 April 2000. 3. Within 60 days after the effective date of this Directive. 4. No later than 30 April 2000. 5. No later than 30 April 2000. This Airworthiness Directive becomes effective on 17 June 1999. Background: Transport Canada Civil Aviation has advised that the initial type approval for the DHC-3 aircraft was ICAO Annex 8, 2nd Edition (Transport Category D) which specifies fire detecting and extinguishing provisions. Maintaining a serviceable fire detection system has proved difficult, primarily due to the fire detection sensing element having been time expired, replacement unavailable and no available approved substitute. A few approvals were previously granted by Transport Canada to authorise the removal of the fire detection and extinguishing system. COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES This Directive has been issued to provide a temporary alleviation for those aeroplanes that are out of compliance with the DHC-3 type approval basis due to the FIREX and/or FIRDET systems being inoperative, time expired or having previously been granted permission to remove the fire detection and extinguishing system.