{"id":"F2006B07010","name":"AD/SF340/8 Amdt 1 - MLG Separation Bolt Harness","slug":"ad-sf340-8-amdt-1-mlg-separation-bolt-harness","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48653,"registerId":"commonwealth-F2006B07010-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SF340/8 Amdt 1 - MLG Separation Bolt Harness","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)  SAAB SF340 Series Aeroplanes\n\n \n\nAD/SF340/8\n\nAmdt 1\n\n\nMLG Separation Bolt Harness 9/88\n\n \n\nApplicability: SAAB SF340A aircraft S/No 3 to 108 inclusive.\n\n \n\nRequirement: Comply with SAAB SB SF340-32-028 Revision 1 and SB SF340-32-041 Revision 1.\n\n \n\nNote: Swedish Airworthiness Directive SAD No 1-023 refers.\n\n \n\nCompliance: Modify prior to 11 April 1988.\n\n \n\nBackground:  Service experience has shown that the electrical harness to the main landing gear explosive bolt is vulnerable to breakage. Lack of explosive bolt function when using the emergency extension system could result in a hazardous situation. Amdt 1 to this Directive is issued to amend the revision status of the Requirement document only.\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\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"Amdt 1 does not broaden or narrow the set of required actions; it amends only the revision status of the requirement documents. The substantive obligation—to modify the MLG explosive-bolt electrical harness on SAAB SF340A serial numbers 3–108 by following the named Saab service bulletins and completing the work before 11 April 1988—remains the same. (Requirement; Background; Compliance)"},"complexity_factors":["Narrow applicability (specific aircraft serial numbers 3–108) reduces scope complexity. (Applicability)","Prescriptive requirement to follow two named service bulletins at a specified revision simplifies compliance choices but creates a need to obtain and apply exact documents. (Requirement)","Fixed compliance deadline adds scheduling and operational complexity for operators. (Compliance)","Safety-critical technical work increases practical implementation risk despite clear instructions. (Background; Requirement)","Amendment changes only the revision status of documents, not the substantive obligation, so legal scope is straightforward. (Background)"],"plain_english_summary":"What the directive does, in plain terms\n\n- Mechanically, this Airworthiness Directive orders operators of certain SAAB SF340A aeroplanes to modify the electrical harness that connects to the main landing gear (MLG) explosive bolt by following two specific Saab Service Bulletins (SB SF340-32-028 Revision 1 and SB SF340-32-041 Revision 1). (Requirement)\n- It applies to SAAB SF340A aircraft with serial numbers 3 through 108 inclusive. (Applicability)\n- The modification must be carried out before 11 April 1988. (Compliance)\n\nWhy the regulator says it is required\n\n- The stated reason is that service experience showed the harness to the MLG explosive bolt can break, and if the explosive bolt does not operate when the emergency extension system is used, a hazardous situation could result. The directive therefore mandates the modification to address that vulnerability. (Background)\n- The amendment labelled “Amdt 1” changes the revision status of the requirement documents only, not the underlying action. (Background)\n\nWho pays and who decides\n\n- Aircraft owners/operators are required to arrange and pay for the modification because the directive applies to those specific aircraft and imposes a mandatory modification. (Applicability; Compliance; Requirement)\n- The Civil Aviation Safety Authority issued the directive and prescribes the precise technical documents (the Saab service bulletins) that must be used. (Requirement)\n\nPractical effects and incentives\n\n- Operators must schedule the modification into maintenance programmes and may need to ground aircraft temporarily until the work is complete (Compliance). That creates direct costs (labour, parts, and out-of-service time) and an operational scheduling decision.\n- The mandated change reduces the specific operational risk identified in the background: failure of the explosive bolt during emergency gear extension. That creates a clear safety incentive for operators to comply. (Background)\n\nCompliance burden and implementation risk\n\n- The directive is prescriptive: it requires compliance with two named service bulletins at the specified revision level. Operators must obtain and follow those exact documents, which concentrates the technical compliance requirement into a defined set of instructions. (Requirement)\n- Implementation risk includes the usual hazards of technical maintenance work (correct application of the service instructions, parts availability and workmanship). The directive’s prescription of specific SB revisions reduces ambiguity about which instructions to follow but requires operators to ensure the correct revision is used. (Requirement)\n\nTrade-offs, opportunity costs and market effects\n\n- The trade-off faced by operators is short-term cost and downtime versus reduced risk of a hazardous failure during emergency gear extension. (Background; Compliance)\n- Maintenance providers and approved repair organisations are the likely suppliers of the required work; the directive increases demand for that specific maintenance on the affected fleet while imposing costs on operators. (Applicability; Requirement)\n\nScope and discretion\n\n- The AD sets a clear, non-discretionary obligation for the identified aircraft to be modified by a fixed date; there is little operational discretion left to an operator beyond scheduling and performing the mandated modification according to the named service bulletins. (Requirement; Compliance)\n\nSources cited: Applicability; Requirement; Compliance; Background."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is Amendment 1 to an existing directive, and it explicitly states it only updates the revision status of the required documents. The scope remains identical to the original AD — same aircraft, same safety issue, same modification required. No expansion of coverage or purpose."},"complexity_factors":["Very short document (under 200 words)","Only 2 defined references (the SAAB service bulletins)","Single, unambiguous applicability criterion (specific aircraft serial numbers)","No nested conditions or exceptions","No cross-references to other legislation beyond a single note about a Swedish directive","Straightforward compliance deadline with no alternative methods"],"plain_english_summary":"**What this is:** An Airworthiness Directive (AD) — essentially a mandatory safety notice issued by Australia's Civil Aviation Safety Authority (CASA) telling aircraft owners and operators they must fix a specific mechanical problem.\n\n**What it does:** Orders owners of certain SAAB SF340A aircraft (serial numbers 3 through 108) to modify the electrical wiring (the \"harness\") connected to the main landing gear's explosive bolt. This bolt is part of the emergency landing gear extension system — if it doesn't work, the landing gear might not deploy in an emergency.\n\n**Why it matters:** The original wiring was breaking. If the explosive bolt fails to fire when needed, the landing gear won't extend, creating a serious crash risk. This amendment (Amdt 1) simply updates which version of the manufacturer's service bulletins must be followed — it doesn't change the actual safety fix required.\n\n**Who must act:** Anyone operating SAAB SF340A aircraft with serial numbers 3–108. They had to complete this modification before 11 April 1988.\n\n**Key point:** This is a retrospective safety mandate — it applies to aircraft already in service, not just new ones."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sf340-8-amdt-1-mlg-separation-bolt-harness","history":"/api/acts/ad-sf340-8-amdt-1-mlg-separation-bolt-harness/history","analysis":"/api/acts/ad-sf340-8-amdt-1-mlg-separation-bolt-harness/analysis","conflicts":"/api/acts/ad-sf340-8-amdt-1-mlg-separation-bolt-harness/conflicts","importantCases":"/api/acts/ad-sf340-8-amdt-1-mlg-separation-bolt-harness/important-cases","documents":"/api/acts/ad-sf340-8-amdt-1-mlg-separation-bolt-harness/documents"}}