{"id":"F2006B09257","name":"AD/DHC-8/98 Amdt 1 - Engine Oil Coolers","slug":"ad-dhc-8-98-amdt-1-engine-oil-coolers","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":53212,"registerId":"commonwealth-F2006B09257-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DHC-8/98 Amdt 1 - Engine Oil Coolers","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nOn the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/DHC-8/98 and issues the following AD under subregulation 39.1 (1) of CASR 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\nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\nAD/DHC-8/98\n\nAmdt 1\n\n  \nEngine Oil Coolers 8/2004\n\nApplicability: Model DHC-8 aeroplanes on which engine oil coolers have been installed per LORI, Inc., Supplemental Type Certificate SA8937SW.\n\nNote 1: These oil coolers may be installed on but may not be limited to Model DHC- 8-101, -102, -103, -106, -201, -202, -301, -311, -314, and –315 aeroplanes.\n\nRequirement: 1. Carry out a review of aeroplane maintenance records, or a detailed inspection in accordance with the Accomplishment Instructions of Honeywell Service Bulletin 28E99-79-2036, dated September 23, 2002, to positively determine the part numbers (P/N) and serial numbers (S/N) of the engine oil coolers. If neither engine oil cooler has a S/N as listed in Table 1 of the service bulletin, no further action is required.\n\n2a. If only one engine oil cooler has a S/N as listed in Table 1: remove the affected part and install a part that has been reworked per the service bulletin.\n\n2b. If both engine oil coolers have S/Ns as listed in Table 1 of the service bulletin: remove the affected parts and install a part that has been reworked per the service bulletin.\n\n3. Do not install an engine oil cooler having a S/N as listed in Table 1 of Honeywell Service Bulletin 28E99-79-2036, dated September 23, 2002.\n\nNote 2: FAA AD 2004-09-31 Amdt 39-13621 refers.\n\nCompliance: For Requirement 1: Unless previously accomplished, within 7 days after the effective date of this AD,\n\nFor Requirement 2a: Unless previously accomplished, within 90 days after the effective date of this AD.\n\nFor Requirement 2b: At least one of the oil coolers must be replaced before further flight with the second oil cooler to be replaced within 90 days from the effective date of this Directive.\n\nFor Requirement 3: From the effective date of this Directive.\n\nBombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes\n\nAD/DHC-8/98 Amdt 1 (continued)\n\nThis Amendment becomes effective on 5 August 2004.\n\nBackground: This action is necessary to prevent oil leakage from the engine oil coolers, consequent in-flight engine shutdown due to low oil pressure, and reduced controllability of the aeroplane. This action is intended to address the identified unsafe condition.\n\nThis amendment changes the applicability of the Directive by removing reference to specific models, but retaining the reference to the Lori STC, which is the determining feature for action to take place.\n\nThe original issue of this Directive became effective on 8 July 2004.\n\n![](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 23 June 2004\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 14 July 2004.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The amendment removes references to specific DHC‑8 models and instead limits applicability by the LORI STC (SA8937SW). Other substantive requirements remain: inspect/identify affected serial numbers, replace with reworked parts, and prohibit installation of listed units. The amendment’s effective date was set later than the original AD’s effective date."},"complexity_factors":["Applicability tied to a Supplemental Type Certificate (LORI STC SA8937SW) rather than aircraft model lists","Identification depends on matching part and serial numbers against Table 1 in Honeywell Service Bulletin 28E99-79-2036","Multiple compliance timeframes (7 days, 90 days, and before further flight for one cooler)","Requirement to install parts reworked per the referenced Honeywell service bulletin","Prohibition on future installation of affected serial-numbered coolers","Cross-reference to FAA AD and Honeywell service bulletin introduces reliance on external documents"],"plain_english_summary":"This Airworthiness Directive requires operators of DHC‑8 aeroplanes fitted with LORI STC SA8937SW engine oil coolers to check records or inspect the coolers, identify listed serial numbers, remove and fit reworked replacements where required, and prohibits installing affected serial‑numbered coolers. CASA (via its delegate) sets short compliance deadlines (inspection within 7 days; replacements within 90 days or before further flight as specified). The stated purpose is to prevent oil leaks and in‑flight engine shutdowns; operators pay for inspections, removals and replacement parts."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is an amendment to an existing directive, but it narrows rather than expands scope. The amendment removes specific model references (DHC-8-101, -102, etc.) and instead relies solely on the STC reference to determine applicability. This is a technical refinement to avoid ambiguity, not a scope expansion. The core purpose—addressing unsafe oil coolers—remains unchanged from the original July 2004 directive."},"complexity_factors":["Short, single-purpose document (approximately 400 words)","Only 2 defined terms requiring external reference (Honeywell Service Bulletin 28E99-79-2036 and FAA AD 2004-09-31)","Clear conditional logic with only two branches (one faulty cooler vs. two faulty coolers)","Simple compliance structure with three distinct deadlines (7 days, 90 days, immediate)","Minimal cross-referencing—only refers to one external technical document and one US regulatory equivalent","Straightforward applicability test (presence of specific STC modification)"],"plain_english_summary":"This CASA safety order targets Bombardier DHC‑8 (Dash 8) aircraft fitted with Honeywell engine oil coolers under STC SA8937SW, requiring operators to inspect records/aircraft promptly and identify affected part/serial numbers. \n\nIt mandates rapid replacement of defective coolers (checks within seven days; faulty units replaced within 90 days, and if both coolers are defective at least one must be replaced before further flight) to prevent oil leaks that can cause sudden engine shutdown."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dhc-8-98-amdt-1-engine-oil-coolers","history":"/api/acts/ad-dhc-8-98-amdt-1-engine-oil-coolers/history","analysis":"/api/acts/ad-dhc-8-98-amdt-1-engine-oil-coolers/analysis","conflicts":"/api/acts/ad-dhc-8-98-amdt-1-engine-oil-coolers/conflicts","importantCases":"/api/acts/ad-dhc-8-98-amdt-1-engine-oil-coolers/important-cases","documents":"/api/acts/ad-dhc-8-98-amdt-1-engine-oil-coolers/documents"}}