{"id":"F2006B08659","name":"AD/COOL/2 - Stewart Warner Oil Coolers - Inspection and Replacement","slug":"ad-cool-2-stewart-warner-oil-coolers-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":51750,"registerId":"commonwealth-F2006B08659-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/COOL/2 - Stewart Warner Oil Coolers - Inspection and Replacement","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCoolers\n\nAD/COOL/2 Stewart Warner Oil Coolers \\- Inspection NK\n\nand Replacement\n\nApplicability: Stewart Warner Oil Coolers:\n\n| Stewart-Warner Model Numbers | Begining Serial Numbers | Ending Serial Numbers |\n| ---------------------------- | ----------------------- | --------------------- |\n| 8406J                        | 12558                   | 16212                 |\n| 8406L                        | 1496                    | 1763                  |\n| 8432K                        | 514                     | 541                   |\n| 8432L                        | 631                     | 964                   |\n| 10568C                       | 1105                    | 1141                  |\n| 10578B                       | 2212                    | 2316                  |\n| 10599A                       | 7369                    | 9013                  |\n| 10610A                       | 815                     | 1956                  |\n| 10614A                       | 732                     | 947                   |\n| 10622A                       | 334                     | 394                   |\n| 10634D                       | 105                     | 907                   |\n| 8446C                        | 575                     | 629                   |\n| 8437C                        | 422                     | 472                   |\n| 10641B                       | 143                     | 162                   |\n| 8493B                        | 1269                    | 1603                  |\n\nWhich do not have a date ink stamped next to the nameplate.\n\nNote: Oil coolers of the above model and S/Nos. that do have a date ink stamped next to the nameplate have been inspected and found satisfactory for continued use.\n\nRequirement: 1. Inspect the engine oil cooler for applicability within the affected model and serial number range.\n\n    2. If the oil cooler has accumulated 10 hours or less time in service since new, replace with a serviceable cooler not of the above serial numbered range unless the serial number has a date ink stamped next the oil cooler nameplate.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n    3. If the oil cooler has accumulated more than 10 hours time in service since new, inspect the cooler for oil leakage.\n\n    4. If leakage is evident, replace cooler as in paragraph 2.\n\n    5. If no leakage is evident, fabricate and install the following placard on the aircraft instrument panel:\n\n\"Visually inspect oil cooler for leakage prior to each flight\".\n\nNote 1: FAA AD 80-25-07 refers.\n\nNote 2: This inspection may be performed by the pilot.\n\nThese oil coolers may be installed on, but not limited to, the following aircraft:\n\n| Bellanca Models :          | 7GCAA, 7GCBC, 7KCAB, 8GCBC and 8KCAB.           |\n| -------------------------- | ----------------------------------------------- |\n| Cessna Models:             | 152, A152, F152, FA152, 172I, 172K, 172L, 172M, |\n| (including Reims Aviation) | 172N, 172P, 172RG, F172L, F172M, F172P, 177,    |\n|                            | 177A, 177B, 177RG, F177RG, R182, FR182, TR182,  |\n|                            | T182, A188B, T188C, 210N, T210N and P210N.      |\n| Piper Models:              | PA-38-112 and PA-44.                            |\n| Mooney Models:             | M20C, M20E, M20F, M20G and M20J.                |\n| Great Lakes Models:        | 2T-1A-1 and 2T-1A-2.                            |\n| Beech Models:              | 76, 77 and C-23.                                |\n\nCompliance: For Para. 2 \\- Inspect before further flight. Replace within 10 hours time in service.\n\nFor Para. 3 \\- Inspect before further flight.\n\nBackground: Improper heat treatment during manufacture has resulted in several failures of oil coolers overseas. In flight failure of an oil cooler may be a fire hazard.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific manufacturing defect in specific oil cooler units. The scope remains precisely focused on the identified defective parts and affected aircraft models. No scope creep is evident."},"complexity_factors":["Multiple conditional branches based on flight hours (≤10 vs >10) and presence of date stamp","Cross-reference to US FAA AD 80-25-07","Detailed tabular data for model/serial number ranges (15 model types with specific serial ranges)","Specific placard wording requirement","Dual compliance timelines (immediate inspection vs 10-hour replacement window)"],"plain_english_summary":"This CASA Airworthiness Directive mandates inspections or replacement of certain Stewart Warner oil coolers (specified models/serial ranges) that may have been improperly heat‑treated and can crack and leak, risking engine fire. It affects owners/operators of listed aircraft when the cooler lacks a date stamp. New coolers must be replaced within 10 flight hours; in‑service coolers must be checked for leaks before next flight, replaced if leaking, or a cockpit placard installed. Pilots may perform the visual checks."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD is narrowly targeted to specific Stewart‑Warner oil cooler models and serial‑number ranges exhibiting manufacturing heat‑treatment problems. The measures are consistent with the original safety objective (identify and remove potentially defective coolers or require pre‑flight checks). It does not expand the instrument’s scope beyond addressing those specific parts and the aircraft on which they may be installed; it remains within the original safety‑remediation purpose."},"complexity_factors":["15 affected models with multiple serial‑number ranges listed (table complexity)","Binary exemption based on presence of a date ink stamp next to the nameplate","Two conditional pathways depending on time in service (≤10 hours vs >10 hours)","Short compliance timing (inspect before further flight; replace within 10 hours for low‑time coolers)","Requirement to fabricate and install a placard (administrative/physical compliance)","Pilot allowed to perform inspection (delegation of maintenance check to non‑maintenance personnel)","Cross‑reference to FAA AD 80‑25‑07"],"plain_english_summary":"**What this instrument does (mechanics)**\n\n- It is an Airworthiness Directive (AD) ordering owners/operators to inspect certain Stewart‑Warner engine oil coolers (specific models and serial number ranges listed) and to replace or mark the aircraft depending on the inspection outcome. The AD applies only to coolers listed in the table and only to those *without* a date ink‑stamped next to the cooler nameplate (the date stamp indicates an earlier satisfactory inspection).\n\n- The required steps (numbering follows the AD):\n  1. Confirm whether the oil cooler on the aircraft is one of the affected models and serial numbers.\n  2. If that cooler has accrued 10 hours or less since new, it must be replaced with a serviceable cooler that is *not* from the affected serial number ranges — unless the cooler bears a date ink stamp by the nameplate (in which case it was previously inspected and is acceptable).\n  3. If the cooler has more than 10 hours since new, visually inspect it for oil leakage before the next flight.\n  4. If any leakage is found, replace the cooler as required in step 2.\n  5. If no leakage is found, install a placard on the instrument panel reading: “Visually inspect oil cooler for leakage prior to each flight.”\n\n- Timing (compliance):\n  - For coolers with ≤10 hours: inspect before further flight and replace within 10 hours time in service.  \n  - For coolers >10 hours: inspect for leakage before further flight.\n\n- Notes and cross‑reference: The AD refers to FAA AD 80‑25‑07 and explicitly allows the pilot to perform the inspection.\n\n**Who is affected**\n\n- Aircraft owners/operators with any of the listed Stewart‑Warner oil cooler models and serial numbers installed and that do not have a date ink stamp next to the nameplate. The AD lists many general aviation types (Cessna, Piper, Mooney, Beech, Bellanca, Great Lakes, etc.) as aircraft on which these coolers may be installed.\n\n**Why it matters (stated purpose and practical trade‑offs)**\n\n- Stated purpose: some coolers suffered improper heat treatment during manufacture, causing failures overseas; an in‑flight failure could present a fire hazard. The AD aims to identify and remove potentially defective coolers from service quickly.\n\n- Who pays: aircraft owners/operators bear the costs (inspection time, possible replacement part purchase and installation, and fabrication/installation of a placard).\n\n- Who decides and how behaviour changes: CASA (Civil Aviation Safety Authority) issues the AD; owners/operators must follow it. Operators must check nameplates/serial numbers and either replace or add the placard and perform pre‑flight leak checks. Pilots may perform the visual inspection themselves, reducing reliance on maintenance personnel.\n\n**Implementation details, incentives and risks**\n\n- Cost and availability: Replacing a cooler within 10 hours for low‑time units creates a short window for acquiring a permissible serviceable cooler. If replacement parts are scarce or costly, operators face economic pressure or temporary grounding.\n\n- Compliance burden: Operators must inspect nameplates for an ink date (a binary, low‑skill check) and maintain accurate time‑in‑service records for the cooler to determine the ≤10 / >10 hours pathway.\n\n- Verification and fraud risk: the AD relies on a visible ink date by the nameplate as proof of prior inspection; operators and inspectors must accept the stamp as genuine and correctly associated with the cooler’s serial number.\n\n- Safety trade‑off: for coolers with >10 hours, the AD permits continued use if there is no visible leakage, but mandates a visible placard and pre‑flight checks — this shifts some ongoing safety responsibility to pilots performing visual inspections.\n\n- Administrative cross‑reference: the AD incorporates an FAA AD as background; operators with international registrations should note this linkage.\n\n**Net effect**\n\n- Concentrated costs fall on owners/operators of affected aircraft (inspection, replacement, parts procurement); benefits (reduced risk of in‑flight cooler failure and potential fire) are safety‑oriented and diffuse. The AD imposes a short compliance timetable for low‑time coolers and an ongoing pre‑flight inspection regime for others.\n\n(References: AD paragraph numbers 1–5; affected model/serial table; Notes 1–2.)"},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-cool-2-stewart-warner-oil-coolers-inspection-and-replacement","history":"/api/acts/ad-cool-2-stewart-warner-oil-coolers-inspection-and-replacement/history","analysis":"/api/acts/ad-cool-2-stewart-warner-oil-coolers-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-cool-2-stewart-warner-oil-coolers-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-cool-2-stewart-warner-oil-coolers-inspection-and-replacement/important-cases","documents":"/api/acts/ad-cool-2-stewart-warner-oil-coolers-inspection-and-replacement/documents"}}