{"id":"F2006B03341","name":"AD/B767/164 - Oil Filter Differential Pressure Switch","slug":"ad-b767-164-oil-filter-differential-pressure-switch","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42778,"registerId":"commonwealth-F2006B03341-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# ![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor 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.\n\n![](image.001.png)\n\nBoeing 767 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/B767/164 Oil Filter Differential Pres","sectionType":"part","heading":"AD/B767/164 Oil Filter Differential Pressure Switch 3/2002","content":"# AD/B767/164 Oil Filter Differential Pressure Switch 3/2002\n\nApplicability: 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.\n\nRequirement: 1. Replace the engine oil filter differential switch as follows:\n\n    For Pratt & Whitney PW4000 engines \\- Replace switch part number (P/N) S332T004-23 with a new -23 switch.\n\n    b. For Pratt & Whitney JT9D-7R4 engines \\- Replace switch P/Ns S332T004- 2, -25 or -29 with a new -29 switch.\n\nIncorporation 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.\n\n2. 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.)\n\nNote: FAA AD 91-09-15 Amdt 39-6974 refers.\n\nCompliance: 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.\n\nFor Requirement 2 \\- As of the effective date of this Directive.\n\nThis Airworthiness Directive becomes effective on 21 March 2002.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The Directive remains focused on the originally targeted unsafe condition for specific 767 models and engine types. It prescribes replacement intervals, bans reinstallation after 10,000 hours, and identifies alternative service bulletin-based compliance options, but does not expand coverage to other components, engines, or aircraft beyond those listed."},"complexity_factors":["Technical specificity: multiple exact part numbers required for replacement (e.g. S332T004-23, -29, 21-SN04-403, 21-SN04-415, S332T004-32).","Dual-engine applicability: different requirements for Pratt & Whitney JT9D-7R4 versus PW4000 engines.","Recurring compliance schedule: initial compliance window (60 days or before 10,000 hours) and mandatory repetition at intervals not exceeding 10,000 hours TIS.","Alternate compliance paths: incorporation of various Boeing Service Bulletins and specific part numbers constitute terminating action for certain inspections.","Lifecycle constraint: prohibition on reinstalling switches removed after 10,000 hours and explicit statement that reworking/overhauling does not reset service hours — affects inventory and maintenance decisions.","External references: cross-reference to FAA AD and multiple service bulletins increases document dependencies and verification steps.","Applicability depends on external SB list: the scope references Boeing SB 767-79-0008 for applicability, requiring operators to consult that bulletin."],"plain_english_summary":"This Airworthiness Directive requires operators of listed Boeing 767 aeroplanes with JT9D-7R4 or PW4000 engines to replace specified engine oil‑filter differential pressure switches on a recurring basis (no more than every 10,000 hours TIS) and bans reinstalling switches that have accumulated 10,000 hours. The AD lists acceptable replacement parts and specific service bulletins as alternate methods of compliance. It matters because it mandates a maintenance action to address a identified unsafe condition in the affected components."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope focused on specific oil filter differential pressure switches on Boeing 767 aircraft with particular Pratt & Whitney engines. The alternate compliance methods and cross-referenced service bulletins are standard aviation safety regulatory practice and do not represent scope creep."},"complexity_factors":["Multiple part number variations requiring different replacement actions (P/N S332T004-23, -2, -25, -29, plus alternate P/Ns 21-SN04-403, 21-SN04-415, S332T004-32)","Cross-reference to external Boeing Service Bulletins (SB 767-79-0008, SB 767-79-0020, SB 769-79-0013) and FAA AD 91-09-15","Conditional compliance timeline with 'whichever occurs first' logic (60 days vs 10,000 hours TIS)","Alternate method of compliance provisions with specific terminating action for repetitive inspections","Time-in-service (TIS) tracking requirement with prohibition on reinstallation regardless of rework status"],"plain_english_summary":"This CASA safety order requires operators of Boeing 767s with Pratt & Whitney JT9D‑7R4 or PW4000 engines to replace specified engine oil filter differential pressure switches with approved units, initially within 60 days or before 10,000 flight hours and thereafter every 10,000 hours. It also bans reinstalling switches that have reached 10,000 hours.\n\nThe rule affects airlines, maintenance organisations and any operators with the specified engine/switch combinations to prevent undetected filter clogging and potential in‑flight engine damage."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b767-164-oil-filter-differential-pressure-switch","history":"/api/acts/ad-b767-164-oil-filter-differential-pressure-switch/history","analysis":"/api/acts/ad-b767-164-oil-filter-differential-pressure-switch/analysis","conflicts":"/api/acts/ad-b767-164-oil-filter-differential-pressure-switch/conflicts","importantCases":"/api/acts/ad-b767-164-oil-filter-differential-pressure-switch/important-cases","documents":"/api/acts/ad-b767-164-oil-filter-differential-pressure-switch/documents"}}