{"id":"F2006B07018","name":"AD/SF340/87 - Sealing Around Terminal Lugs on Fire Detectors","slug":"ad-sf340-87-sealing-around-terminal-lugs-on-fire-detectors","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48678,"registerId":"commonwealth-F2006B07018-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/87 - Sealing Around Terminal Lugs on Fire Detectors","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)  \n\nAIRWORTHINESS DIRECTIVE\n\n![](image.001.png)\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 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\nSAAB SF340 Series Aeroplanes\n\nAD/SF340/87 Sealing Around Terminal Lugs on\n\nFire Detectors\n\n  \n13/2002\n\nApplicability: Model SF340A aeroplanes, serial numbers (S/N) 004 through 159 inclusive and Model 340B aeroplanes, S/N 160 through 459 inclusive.\n\nRequirement: Modify the Tailpipe Hot Detection harness in accordance with Saab Aircraft Mandatory Service Bulletin (SB) SAAB 340-26-030 dated 28 October 2002.\n\nPrior modification in accordance with SB SAAB 340-26-018 dated 26 September 1997 and SB SAAB 340-26-029 dated 28 October 2002 is considered acceptable terminating action for this Directive.\n\nNote: LFV AD 1-184 refers.\n\nCompliance: Before 26 December 2003.\n\nThis Airworthiness Directive becomes effective on 26 December 2002.\n\nBackground: False warnings for the tail pipe hot detection system have been reported. This has led to delayed or aborted flights, and when airborne, engine in flight shut downs with a following diversion to the nearest airport. The false warnings are mainly caused by moisture ingress, corroded detectors, and chafed and broken wires for the tail pipe hot detection harness. This Directive requires the resealing of the tail pipe harness to improve moisture protection and strength of the harness.\n\n![Signature of James Coyne Delegate of the Civil Aviation Safety Authority](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 18 November 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 4 December 2002.\n\n  \nPage 1 of 1","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD stays within the original safety-focused purpose described in the background: remedying false tailpipe hot-detection warnings caused by moisture, corrosion and wiring damage. It does not extend the regulatory scope beyond that technical fix — it prescribes a specific harness resealing modification for a defined set of serial-numbered aircraft and accepts prior equivalent manufacturer service bulletin work as terminating action."},"complexity_factors":["Single, narrowly focused requirement (modify tailpipe hot-detection harness).","Applicability limited to two contiguous serial-number ranges (SF340A S/N 004–159; 340B S/N 160–459).","References to three Saab Service Bulletins (SAAB 340-26-030, SAAB 340-26-029, SAAB 340-26-018).","One fixed compliance deadline and one effective date (clear timing).","One cross-reference note to another authority's AD (LFV AD 1-184).","No extensive definitions, no layered exceptions beyond prior-modification acceptance."],"plain_english_summary":"**What this instrument does (mechanically)**\n\n- This is an Airworthiness Directive (a mandatory safety order) issued under the Civil Aviation Regulations 1998 (subregulation 39.1(1)). It requires operators of certain SAAB SF340 aeroplanes to modify the tailpipe hot-detection wiring harness by resealing around the terminal lugs in accordance with the manufacturer's Service Bulletin. (See: Requirement; Applicability; Compliance.)\n\n- It applies to specific serial-numbered aircraft only: SF340A with serial numbers 004–159 and 340B with serial numbers 160–459. (See: Applicability.)\n\n- The required work is the modification of the Tailpipe Hot Detection harness following Saab Mandatory Service Bulletin SAAB 340-26-030 dated 28 October 2002. If an operator has already completed earlier Saab Service Bulletins SAAB 340-26-018 (26 Sep 1997) or SAAB 340-26-029 (28 Oct 2002), those earlier modifications are treated as acceptable terminating action (i.e. they satisfy the AD). (See: Requirement.)\n\n- The AD sets a deadline for compliance: the modification must be done before 26 December 2003. The AD took effect on 26 December 2002. (See: Compliance; Effective date.)\n\n**Why the change is required (official rationale)**\n\n- The background states that the tailpipe hot-detection system has produced false warnings caused mainly by moisture ingress, corroded detectors, and chafed or broken wires in the tailpipe hot-detection harness. Those false warnings have led to delayed or aborted flights and, in some instances, in-flight engine shutdowns and diversions. The modification is intended to improve moisture protection and the mechanical strength of the harness to reduce false warnings. (See: Background.)\n\n**Who is affected and who pays**\n\n- Aircraft owners/operators of the listed SAAB SF340 serial numbers are required to comply. (Applicability.)\n\n- The operator (or owner) is responsible for arranging and paying for the modification called for by the Service Bulletin (parts, labour, downtime). The AD does not fund the work. (Requirement; Compliance.)\n\n**Who decides and how it is enforced**\n\n- The Civil Aviation Safety Authority delegate issued the AD under CAR 1998. Compliance with the AD is mandatory under the regulation cited. Civil aviation regulators may use standard oversight and enforcement powers to ensure operators comply. (Header; signature block.)\n\n**Behavioural and commercial effects (mechanisms, not value judgments)**\n\n- Operators must schedule maintenance work on affected aircraft before the compliance date, causing planned downtime and the direct cost of parts and labour. (Compliance; Requirement.)\n\n- Operators who already completed the earlier listed Service Bulletins can avoid repeating work — that creates a clear compliance incentive to rely on prior-modification records. (Requirement: prior modification accepted as terminating action.)\n\n- Aircraft kept flying without the modification face regulatory non-compliance risk and, depending on oversight, potential grounding or enforcement action. (Implicit from AD being mandatory.)\n\n**Practical trade-offs, costs and implementation risk**\n\n- Direct costs: parts, labour and aircraft out-of-service time. Those costs are borne directly by each operator (Requirement; Compliance).\n\n- Operational risk reducing measure: the intended safety benefit is fewer false hot-pipe warnings and lower probability of unnecessary diversions or in-flight shutdowns (Background). The AD changes maintenance priority and resource allocation towards this harness resealing.\n\n- Implementation risk: correct and complete compliance depends on carrying out the Service Bulletin instructions accurately and retaining clear maintenance records. If the SB is unclear or workmanship is poor, the intended benefit may not be realised. (Requirement; Service Bulletin reliance.)\n\n- Compliance complexity is moderate and concentrated: only a defined set of serial-numbered aircraft are affected, so costs and operational impacts are concentrated on those operators rather than spread across the whole market. (Applicability.)\n\n**Effects on markets and private choice (short assessment)**\n\n- Competition and ownership: the AD does not alter ownership or market structure. It imposes a safety compliance cost on the owners/operators of affected aircraft only. (Applicability; Requirement.)\n\n- Contract freedom and independent businesses: maintenance providers (independent MROs or the manufacturer) can perform the required Service Bulletin work subject to regulatory acceptance; the AD does not specify a provider, so independent businesses may compete to carry out the work. (Requirement — SB-based instruction doesn’t mandate a specific repair shop.)\n\n- Prices and productivity: short-term increased maintenance demand for the specific modification could raise local MRO utilisation and prices for that work; productivity could be reduced temporarily for the aircraft while modification is carried out. (Requirement; Compliance.)\n\n**Concentrated benefits and costs; substitution effects**\n\n- Benefits are primarily safety-related and accrue to the affected aircraft operators, their passengers and regulators (Background). Costs are concentrated on those operators in the form of repair cost and downtime. (Applicability; Requirement.)\n\n- A substitution effect exists: operators may prefer to demonstrate compliance by showing prior SB work (SAAB 340-26-018 or SAAB 340-26-029) rather than carry out the newest SB if earlier work already provides equivalent protection. (Requirement.)\n\n**Summary statement of mechanics**\n\n- Mandatory modification of the tailpipe hot detection harness to the Saab SB SAAB 340-26-030 standard for the listed SF340 serial numbers, to be completed before 26 December 2003; prior listed SBs are accepted as satisfying the requirement. (Applicability; Requirement; Compliance.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This Airworthiness Directive maintains its original narrow scope: addressing a specific unsafe condition in the tailpipe hot detection system of Saab SF340 aircraft. There is no evidence of scope creep; it targets precisely the moisture ingress and wiring issues identified in the background section."},"complexity_factors":["Single, specific technical requirement referencing an external service bulletin","Only 2 defined applicability criteria (model and serial number ranges)","Simple compliance structure with single deadline and one acceptable terminating action","No nested exceptions or conditional logic — only a straightforward note about prior modifications","Length: 1 page with minimal cross-referencing"],"plain_english_summary":"This safety order requires owners/operators of Saab SF340A (S/N 004–159) and SF340B (S/N 160–459) to reseal wiring on the tailpipe hot detection system to stop moisture ingress that causes corrosion, false overheat warnings, and equipment failures. Affecting about 456 aircraft, the fix prevents in-flight engine shutdowns, diversions, and service disruptions. The measure took effect 26 Dec 2002 and must be completed by 26 Dec 2003 (exempt if covered by earlier service bulletins)."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-87-sealing-around-terminal-lugs-on-fire-detectors","history":"/api/acts/ad-sf340-87-sealing-around-terminal-lugs-on-fire-detectors/history","analysis":"/api/acts/ad-sf340-87-sealing-around-terminal-lugs-on-fire-detectors/analysis","conflicts":"/api/acts/ad-sf340-87-sealing-around-terminal-lugs-on-fire-detectors/conflicts","importantCases":"/api/acts/ad-sf340-87-sealing-around-terminal-lugs-on-fire-detectors/important-cases","documents":"/api/acts/ad-sf340-87-sealing-around-terminal-lugs-on-fire-detectors/documents"}}