AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section. Boeing 767 Series Aeroplanes AD/B767/164 Oil Filter Differential Pressure Switch 3/2002 Applicability: Model 767 series aeroplanes, as listed in Boeing Service Bulletin (SB) 767-79-0008 dated 11 August 1988 equipped with engine oil filter differential pressure switches on JT9D-7R4 engines and all Model 767 series aeroplanes with PW4000 engines equipped with engine oil filter differential pressure switches. Requirement: 1. Replace the engine oil filter differential switch as follows: 1. For Pratt & Whitney PW4000 engines - Replace switch part number (P/N) S332T004-23 with a new -23 switch. b. For Pratt & Whitney JT9D-7R4 engines - Replace switch P/Ns S332T004- 2, -25 or -29 with a new -29 switch. Incorporation of switches P/N 21-SN04-403 or 21-SN04-415 in accordance with SB 767-79-0020 dated 14 November 1996 or Revision 1 dated 18 June 1998, as applicable, or P/N S332T004-32 in accordance with either SB 769- 79-0013 Revision 3 dated 7 January 1999 or Revision 4 dated 19 December 2001 is considered an alternate method of compliance to this Directive and terminating action for the Requirement 1.b. repetitive inspections. 2. Pressure switches removed following the accumulation of 10,000 hours time in service (TIS) shall not be reinstalled on any aeroplane. (Reworking, modifying or overhauling a used switch does not zero time the switch.) Note: FAA AD 91-09-15 Amdt 39-6974 refers. Compliance: For Requirement 1 - Initially, if not previously accomplished, within 60 days after the effective date of this Directive or before the accumulation of 10,000 hours total TIS, whichever occurs first, and thereafter at intervals not to exceed 10,000 hours TIS. If the switch has been previously replaced, continue to replace the switch at intervals not to exceed 10,000 hours TIS from the last switch replacement. For Requirement 2 - As of the effective date of this Directive. This Airworthiness Directive becomes effective on 21 March 2002. Boeing 767 Series Aeroplanes AD/B767/164 (continued) Background: The United States Federal Aviation Administration received reports of in-flight engine shutdowns due to either Engine Indicating and Crew Alerting System (EICAS) indication of oil filter bypass or loss of oil quantity due to a leak in the oil filter differential pressure switch. This Directive introduces measures to prevent false oil filter bypass indication or loss of oil quantity. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 7 February 2002 The above AD is notified in the Commonwealth of Australia Gazette on 27 February 2002.