{"id":"F2006B04928","name":"AD/CESSNA 150/30 Amdt 1 - Exhaust Heat Exchanger","slug":"ad-cessna-150-30-amdt-1-exhaust-heat-exchanger","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44773,"registerId":"commonwealth-F2006B04928-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 150/30 Amdt 1 - Exhaust Heat Exchanger","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Cessna 150, F150, 152 & F152 Series Aeroplanes\n\n \n\nAD/CESSNA 150/30\n\nAmdt 1\n\n\nExhaust Heat Exchanger 3/79\n\n \n\nApplicability: Models: 152 with S/Nos 15279406 to 15282919. A152 with S/No. A1520735 to A1520845, fitted with a KMR Industries P/N 1-1000 exhaust system, either bearing S/No. 1 to 3999 or having an “R” prefix or suffix on any Serial No.\n\n \n\nRequirement: Action in accordance with Cessna SL No. SE 78-71.\n\n \n\nCompliance: Before further flight after 22 January 1979 and thereafter at intervals not exceeding 50 hours time in service until paragraph “B” of Cessna SL No. SE 78-71 is complied with.\n\n \n\nNote: Compliance with the previous issue of this Directive does NOT constitute compliance with this issue of the Directive.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a targeted safety directive addressing a specific mechanical defect in a narrow subset of aircraft. The amendment appears to tighten or clarify the original requirements (as indicated by the note that previous compliance doesn't satisfy this version), but has not expanded beyond its original purpose of ensuring exhaust heat exchanger safety in affected Cessna 152 series aircraft."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined elements: specific aircraft models, serial number ranges, manufacturer part numbers, and service letter reference","Single compliance pathway with clear time trigger (before further flight after fixed date) and recurring interval (50 hours)","No nested exceptions or conditional logic — applicability is a straightforward mechanical check (serial numbers and part numbers)","Cross-reference to external document (Cessna SL No. SE 78-71) but no internal cross-references within the instrument itself"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to specific **Cessna 152 and A152 aircraft** (small, two-seat training planes) that have a particular type of exhaust system made by KMR Industries.\n\n**What it does:**\nThe directive requires owners/operators to inspect or take action on the **exhaust heat exchanger** — a component that uses hot exhaust gases to warm the cabin (critical for safe flight in cold conditions). The concern is that this part could fail, potentially leading to carbon monoxide entering the cabin or fire hazards.\n\n**Who must act:**\n- Owners of Cessna 152 aircraft with serial numbers 15279406 to 15282919\n- Owners of A152 aircraft with serial numbers A1520735 to A1520845\n- **Only if** fitted with KMR Industries exhaust systems with specific serial numbers (1-3999, or any number with an \"R\" prefix or suffix)\n\n**What must be done:**\n- Follow the instructions in **Cessna Service Letter SE 78-71** (a manufacturer bulletin)\n- First inspection required **before the next flight after 22 January 1979**\n- Repeat inspections every **50 hours of flight time** until \"paragraph B\" of that service letter is completed\n\n**Important note:** If you already complied with an earlier version of this directive, you **must comply again** with this amended version — the old compliance doesn't count."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This is an amendment (Amdt 1) that: narrows applicability to specific serial-number ranges and KMR exhaust serials (Applicability); requires actions per Cessna SL SE 78-71 rather than embedding them (Requirement); imposes an initial ‘before further flight after 22 January 1979’ deadline and recurring 50‑hour inspections until paragraph “B” is complied with (Compliance); and expressly states that compliance with the previous issue is insufficient (Note)."},"complexity_factors":["Narrow applicability by specific airframe serial numbers and by exhaust system part/serial numbers (Applicability).","Mandates compliance with an external technical document (Cessna Service Letter SE 78-71) rather than prescribing actions in-line (Requirement).","Time-driven compliance regime: before further flight after a specified date and repeating at intervals not exceeding 50 hours until a defined paragraph is complied with (Compliance).","Explicit statement that prior compliance with an earlier issue does not satisfy this amendment (Note) — creates potential administrative tracking needs for operators.","Operational impact concentrated on affected owners/operators who must source parts/maintenance and document recurring inspections; little direct discretion for regulating authority beyond referencing the Service Letter."],"plain_english_summary":"This airworthiness directive requires owners/operators of certain Cessna 152/A152 aeroplanes fitted with a KMR Industries P/N 1-1000 exhaust system to follow the inspection and corrective actions set out in Cessna Service Letter SE 78-71. Compliance must occur before further flight after 22 January 1979 and then every 50 flight hours until paragraph “B” of the Service Letter is met. Owners/operators pay for and arrange the work; the AD relies on the external Service Letter for technical detail."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-150-30-amdt-1-exhaust-heat-exchanger","history":"/api/acts/ad-cessna-150-30-amdt-1-exhaust-heat-exchanger/history","analysis":"/api/acts/ad-cessna-150-30-amdt-1-exhaust-heat-exchanger/analysis","conflicts":"/api/acts/ad-cessna-150-30-amdt-1-exhaust-heat-exchanger/conflicts","importantCases":"/api/acts/ad-cessna-150-30-amdt-1-exhaust-heat-exchanger/important-cases","documents":"/api/acts/ad-cessna-150-30-amdt-1-exhaust-heat-exchanger/documents"}}