{"id":"F2006B05087","name":"AD/CESSNA 180/74 - Instrument Panel Light Dimming Rheostat","slug":"ad-cessna-180-74-instrument-panel-light-dimming-rheostat","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44997,"registerId":"commonwealth-F2006B05087-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 180/74 - Instrument Panel Light Dimming Rheostat","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCessna 180, 182 and Wren 460 Series Aeroplanes\n\nAD/CESSNA 180/74 Instrument Panel Light Dimming Rheostat 3/94\n\nApplicability: Cessna Model 180H and 180J aircraft with serial numbers 18051446 through 18052384 inclusive.\n\nRequirement: Unless previously accomplished, replace the existing instrument panel light dimming rheostat (some installations will also require the fitting of a doubler) in accordance with the Accomplishment Instructions of Cessna Single Engine Service Bulletin SEB92-33 Revision 2 dated 10 September 1993.\n\nNote: FAA AD 93-24-15 Amdt 39-8764 refers.\n\nCompliance: Prior to 3 October 1994.\n\nBackground: The FAA has advised of a report of an inflight fire in a Cessna Model 172.\n\nThe fire was caused by a short in the electrical wiring controlled by the instrument panel light dimming rheostat. This Directive requires the rheostat to be replaced with an improved version, which is both current-limiting and heat-protected, thus decreasing the probability of an inflight fire being caused by a defective rheostat.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in specific aircraft. It has not expanded beyond its original purpose of mandating a single part replacement to prevent electrical fires."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 defined applicability criteria (model numbers and serial number range)","Single, straightforward requirement with one cross-reference to a manufacturer service bulletin","No nested conditions, exceptions, or legislative cross-references","Clear compliance deadline with no alternative methods or conditional extensions"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of certain Cessna 180H/J (S/N 18051446–18052384) to replace the instrument-panel dimmer (rheostat) — and fit a reinforcing doubler where needed — per Cessna Service Bulletin SEB92‑33 Rev.2. The change installs current‑limiting/heat protection to prevent dimmer overheating and potential in‑flight fires (prompted by a related Cessna 172 fire). Work was required by 3 October 1994."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument mandates a specific retrofit for listed aircraft serial numbers and does not broaden regulatory reach beyond those aircraft. It replaces a component with an improved version to address a particular safety defect; it does not add ongoing obligations or expand applicability in the text provided."},"complexity_factors":["Narrow, specific applicability limited to a short serial-number range (Applicability) which simplifies target population but requires serial-number checks.","Single, well-defined technical action: replace rheostat following the manufacturer's Accomplishment Instructions (Requirement).","Possible additional hardware (doubler) for some installations adds installation variability and part-sourcing complexity (Requirement).","Dependence on Cessna Service Bulletin SEB92-33 Rev 2 for the method and parts creates a dependency on manufacturer documentation and availability (Requirement).","Fixed compliance deadline (Prior to 3 October 1994) imposes scheduling and operational downtime pressure on owners/operators (Compliance).","Cross-reference to FAA AD 93-24-15 introduces inter-jurisdictional traceability and potential alignment issues with FAA documentation (Note).","Risk rationale is technical and specific (inflight fire from wiring short), which narrows scope of required mitigation but demands correct electrical/installation work (Background).","Who pays: costs fall to aircraft owners/operators (implicit from the Requirement and Applicability)."],"plain_english_summary":"Requires owners/operators of *Cessna 180H* and *180J* aircraft (serials 18051446–18052384) to replace the instrument-panel light dimming rheostat with an improved current-limiting, heat‑protected unit per Cessna Service Bulletin SEB92‑33 Rev 2. The stated aim is to reduce the risk of an inflight fire after an FAA-reported fire caused by a rheostat-controlled wiring short; compliance imposes a one-time parts-and-labour cost and short aircraft downtime for affected operators."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-180-74-instrument-panel-light-dimming-rheostat","history":"/api/acts/ad-cessna-180-74-instrument-panel-light-dimming-rheostat/history","analysis":"/api/acts/ad-cessna-180-74-instrument-panel-light-dimming-rheostat/analysis","conflicts":"/api/acts/ad-cessna-180-74-instrument-panel-light-dimming-rheostat/conflicts","importantCases":"/api/acts/ad-cessna-180-74-instrument-panel-light-dimming-rheostat/important-cases","documents":"/api/acts/ad-cessna-180-74-instrument-panel-light-dimming-rheostat/documents"}}