{"id":"F2006B02900","name":"AD/B737/20 Amdt 2 - Engine Fire/Overheat Detection Module","slug":"ad-b737-20-amdt-2-engine-fire-overheat-detection-module","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42242,"registerId":"commonwealth-F2006B02900-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/20 Amdt 2 - Engine Fire/Overheat Detection Module","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)  \nBoeing 737 Series Aeroplanes\n\nAD/B737/20\n\nAmdt 2\n\n  \nEngine Fire/Overheat Detection Module 4/90\n\nApplicability: All model 737-200, \\-300 and \\-400 series aircraft.\n\nRequirement: 1. Inspect the engine fire/overheat detection module to determine the module part number.\n\n2. If part number 10-61096-41, \\-71, \\-81, \\-91, \\-92 or 1062061-1, 2, \\-3, \\-11 or \\-12 is\n\ninstalled, modify the control module in accordance with Walter Kidde Aerospace Service Bulletin 899315-26-326 (for -200 series aeroplanes), or 899315-26-324 (for -300 and -400 series aeroplanes) as applicable.\n\nNote: FAA AD 89-08-12 R1 refers.\n\nCompliance: Prior to 22 August 1990.\n\nBackground: Boeing have advised that certain Walter Kidde engine fire/overheat warning systems may become inoperative after an electrical power transfer, with no indication of failure given to flight crew. This could jeopardize continued safe flight and landing.\n\nAmendment 2 to this Directive is issued to delete reference to the Australian CAA Flight Manual amendment which will be issued separately and to mandate incorporation of the referenced Walter Kidde Service Bulletins.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 2 removes the prior reference to an Australian CAA Flight Manual amendment and instead mandates incorporation of the referenced Walter Kidde Service Bulletins. That changes the practical compliance route from relying in part on a Flight Manual change to requiring technical modification of the control module. (Amendment note; Requirement)."},"complexity_factors":["Narrow technical applicability to specific aircraft models (Applicability).","Detailed list of affected module part numbers requiring inspection (Requirement).","Mandated corrective action references external Walter Kidde Service Bulletins, creating dependency on manufacturer procedures and parts (Requirement).","Fixed, short compliance deadline imposes scheduling and operational disruption on operators (Compliance).","Safety-critical system replacement/modification requires certified maintenance resources and parts, raising direct costs for operators (Requirement; Background).","Reference to related FAA AD increases cross-jurisdictional compliance considerations (Note)."],"plain_english_summary":"This Airworthiness Directive applies to Boeing 737-200, -300 and -400 aeroplanes. It requires operators to inspect engine fire/overheat detection modules and, if certain part numbers are fitted, modify the control module using Walter Kidde service bulletins. (Applicability; Requirement).\n\nOperators/owners must complete the inspection and any required modification before 22 August 1990; the regulator says the action addresses a risk that the warning system can become inoperative after an electrical power transfer without crew indication. (Compliance; Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is Amendment 2 to an existing directive. The amendment note explicitly states it only removes a reference to a separate Flight Manual amendment (which will be issued separately) and formally mandates the Walter Kidde Service Bulletins. This is a minor administrative refinement rather than an expansion of scope. The core safety purpose — fixing the faulty fire detection modules — remains unchanged from the original directive."},"complexity_factors":["Short, single-purpose directive (approximately 200 words)","Only 2 main procedural steps (inspect, then modify if applicable)","Limited applicability (3 specific aircraft model series)","9 specific part numbers listed as triggers for action","2 alternative technical standards referenced (different service bulletins for different aircraft series)","Single cross-reference to FAA AD 89-08-12 R1","No nested exceptions or conditional logic beyond the 'if-then' structure","Clear compliance deadline (prior to 22 August 1990)"],"plain_english_summary":"CASA requires operators of Boeing 737-200, -300 and -400 series to inspect the engine fire/overheat detection module and, if identified as a listed faulty part, modify or replace it per the manufacturer’s service instructions.  \n\nA known defect can cause the fire warning to fail silently after an electrical power transfer, so the AD closes a critical safety gap that could prevent crews detecting an engine fire — vital for airlines and charter operators in Australia."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-20-amdt-2-engine-fire-overheat-detection-module","history":"/api/acts/ad-b737-20-amdt-2-engine-fire-overheat-detection-module/history","analysis":"/api/acts/ad-b737-20-amdt-2-engine-fire-overheat-detection-module/analysis","conflicts":"/api/acts/ad-b737-20-amdt-2-engine-fire-overheat-detection-module/conflicts","importantCases":"/api/acts/ad-b737-20-amdt-2-engine-fire-overheat-detection-module/important-cases","documents":"/api/acts/ad-b737-20-amdt-2-engine-fire-overheat-detection-module/documents"}}