Document ID: chunk:federal_register_of_legislation:F2006B03210:body:0:p2
Version: federal_register_of_legislation:F2006B03210
Segment Type: other
Provision Reference: 
Character Range: 2977–4771

this Directive.

            For Requirement 2 - Before further flight and thereafter at intervals not to exceed 36 months unless Lucas humidifier P/N M01AA0101, M01AB0101, M01AB0102 or M01AB0103 is optionally deactivated.

            For Requirement 3 - Within 36 months after the effective date of this Directive and thereafter at intervals not to exceed 36 months unless Lucas humidifier P/N M01AA0101, M01AB0101, M01AB0102 or M01AB0103 is optionally deactivated.

            For Requirement 4 - Before further flight immediately after the deactivation.

            For Requirement 5.a. - Within 18 months after reactivating the humidifier and thereafter at intervals not to exceed 18 months.

            For Requirement 5.b. - Within 36 months after reactivating the humidifier and thereafter at intervals not to exceed 36 months.

            This Airworthiness Directive becomes effective on 23 December 2004.

            Background: Boeing advised that during routine maintenance checks some engine fire control circuits were found to be faulty due to switch internal continuity failures. The humidified air being provided by the LUCAS Humidifier was identified as the source of mineral build up on APU and engine fire control switch contacts leading to failure of the switches to discharge fire suppressant in the affected area. This could result in an uncontrolled fire that could spread to the strut, wing, or aft body of the aeroplane.

            This action is intended to address the identified unsafe condition by preventing the possibility of mineral build-up on the APU and engine fire shutoff switches.

 James Coyne
 Delegate of the Civil Aviation Safety Authority 11 November 2004

 The above AD is notified in the Commonwealth of Australia Gazette on 1 December 2004.