{"id":"F2006B02951","name":"AD/B737/51 - Outboard Flap Forward Support Fitting Attach Bolts","slug":"ad-b737-51-outboard-flap-forward-support-fitting-attach-bolts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42293,"registerId":"commonwealth-F2006B02951-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B737/51 - Outboard Flap Forward Support Fitting Attach Bolts","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)  Boeing 737 Series Aeroplanes\n\n \n\nAD/B737/51 Outboard Flap Forward Support Fitting Attach Bolts 2/91\n\nApplicability: Model 737-200, -300 and -400 listed in the Requirement document.\n\n \n\nRequirement: Action in accordance with the technical requirements of FAA AD 90-24-04 Amdt 39- 6809.\n\n \n\nNote: Boeing Alert SB 737-57A1206 and Alert SB 737-57A1208 refer.\n\n \n\nCompliance: As specified in the Requirement document with effective date 24 December 1990.\n\n \n\nBackground: Country of origin AD. Fastener fracture in fitting attachment could result in loss of outboard flap.\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\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":5,"scope_assessment":{"changed":false,"description":"The text shows no change of scope from issuing the country-of-origin AD: it adopts the FAA AD 90-24-04 technical requirements for the Model 737-200, -300 and -400 aircraft listed in the Requirement document and sets an Australian effective date of 24 December 1990 (Requirement; Applicability; Compliance). There is no indication in this text of any expansion or narrowing of applicability beyond the listed models or of additional Australian-specific measures."},"complexity_factors":["Delegates technical requirements to an external FAA AD rather than setting them out in full in the Australian text (Requirement).","Cross-references manufacturer Alert Service Bulletins (Note) that operators must obtain and interpret.","Applicability limited to specified aircraft models but depends on a separate Requirement document to list individual serials/airframes (Applicability).","Legal force is compact (short text) but operational complexity arises from aligning local compliance with foreign AD technical steps and timeframes (Requirement; Compliance).","Compliance timing is fixed by an effective date and may interact with operational scheduling and maintenance windows (Compliance)."],"plain_english_summary":"This Australian Airworthiness Directive makes compliance with FAA AD 90-24-04 mandatory for specified Boeing 737-200/300/400 aeroplanes, requiring the inspections/repairs called for by that FAA AD (and referencing Boeing alert service bulletins) to address fractured fasteners that could cause loss of an outboard flap. Owners, operators and maintenance organisations of the listed aircraft must carry out the work and bear its costs, as a safety-driven maintenance mandate."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard airworthiness directive format unchanged from its original purpose. It maintains the traditional CASA approach of incorporating by reference foreign aviation safety requirements rather than rewriting them. The scope remains precisely targeted: specific bolt inspections on specific Boeing 737 models to address a specific fracture risk."},"complexity_factors":["Extremely short document (under 200 words)","No defined terms section — relies entirely on external references","Single operative requirement that incorporates by reference an FAA directive and Boeing service bulletins","No conditional logic, exceptions, or nested provisions within the document itself","Complexity is externalized: the actual technical work is contained in referenced documents (FAA AD 90-24-04 and Boeing Alert SBs) not reproduced here"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific Boeing 737 aircraft.\n\n**What it does:**\n- Requires owners and operators of certain Boeing 737 models (-200, -300, and -400 series) to inspect or replace specific bolts on the outboard flap forward support fitting.\n- The directive references a US Federal Aviation Administration (FAA) safety order (AD 90-24-04) and Boeing service bulletins, meaning Australian operators must follow the same technical steps as American ones.\n\n**Why it matters:**\n- **Safety risk:** If the attach bolts fracture (break), the outboard flap could detach from the wing during flight — a potentially catastrophic failure affecting aircraft control.\n- **Mandatory compliance:** This isn't optional. Aircraft cannot legally fly unless this directive is followed within the specified timeframe (by 24 December 1990 for this initial directive).\n\n**Who it affects:**\n- Airlines and operators flying Boeing 737-200, -300, or -400 aircraft in Australia.\n- Maintenance engineers responsible for inspecting and repairing these specific bolt fittings.\n\n**Key point:** This document doesn't contain the actual technical instructions — it simply \"imports\" the US FAA requirements and makes them legally binding in Australia. Operators must obtain the referenced FAA document and Boeing service bulletins to know exactly what work to perform."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b737-51-outboard-flap-forward-support-fitting-attach-bolts","history":"/api/acts/ad-b737-51-outboard-flap-forward-support-fitting-attach-bolts/history","analysis":"/api/acts/ad-b737-51-outboard-flap-forward-support-fitting-attach-bolts/analysis","conflicts":"/api/acts/ad-b737-51-outboard-flap-forward-support-fitting-attach-bolts/conflicts","importantCases":"/api/acts/ad-b737-51-outboard-flap-forward-support-fitting-attach-bolts/important-cases","documents":"/api/acts/ad-b737-51-outboard-flap-forward-support-fitting-attach-bolts/documents"}}