{"id":"F2006B02723","name":"AD/B727/23 - Inboard Mid-Flap Link Support Beam - Inspection and Modification","slug":"ad-b727-23-inboard-mid-flap-link-support-beam-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42039,"registerId":"commonwealth-F2006B02723-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/23 - Inboard Mid-Flap Link Support Beam - Inspection and Modification","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 727 Series Aeroplanes\n\n \n\nAD/B727/23  Inboard Mid-Flap Link Support Beam - Inspection and Modification\n\n\n3/66\n\n \n\nApplicability: All models. Document: Boeing SB No. 57-62. Compliance: Forthwith.\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\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The source text does not indicate any amendment or change from an earlier stated scope. The AD as published applies to all Boeing 727 models, requires the actions described in Boeing Service Bulletin No. 57-62, and requires compliance forthwith. There is no text in the instrument suggesting a change from an original or prior scope."},"complexity_factors":["Short, focused directive with only three explicit operative lines: applicability, document reference, and compliance timing.","Dependence on an external technical document (Boeing Service Bulletin No. 57-62) for procedural detail increases implementation complexity for operators.","Immediate compliance requirement (\"forthwith\") reduces scheduling flexibility and increases operational impact.","Universal applicability to all Boeing 727 models widens the affected population but does not add technical complexity to the AD text itself.","Lack of stated alternatives, inspection intervals, or certification steps in the AD shifts procedural complexity to maintenance organisations and the referenced service bulletin."],"plain_english_summary":"What this instrument does, mechanically:\n\n- It requires inspection and modification of the inboard mid-flap link support beam on Boeing 727 series aeroplanes. The required work is the work described in Boeing Service Bulletin No. 57-62 (Document: Boeing SB No. 57-62). (See: \"Document: Boeing SB No. 57-62\".)\n- It applies to all Boeing 727 models. (See: \"Applicability: All models\".)\n- Compliance is required immediately — \"forthwith\" — meaning there is no deferred compliance period in the text of the directive. (See: \"Compliance: Forthwith\".)\n\nWho is affected and who decides:\n\n- The directive is issued under the Civil Aviation Safety Authority framework (Commonwealth of Australia, Civil Aviation Regulations 1998, Part 39). The regulator is the issuing authority. (See heading: \"Civil Aviation Safety Authority\".)\n- The practical duties created by the directive fall on the parties responsible for aircraft airworthiness: aircraft owners/operators and the maintenance organisations that carry out inspections and modifications. Those parties must follow the Boeing Service Bulletin referenced for the technical steps. (See: \"Document: Boeing SB No. 57-62\" and \"Applicability: All models\".)\n\nWho pays and what the immediate burdens are:\n\n- Costs for inspection and any required modifications will be borne by the aircraft owner/operator or the organisation that contracts for the maintenance work. The directive itself specifies the required action and the service bulletin to follow; it does not allocate funding. (See: \"Document: Boeing SB No. 57-62\" and \"Applicability: All models\".)\n- The compliance timing is immediate (\"forthwith\"), so owners/operators may face immediate operational and scheduling impacts while arranging inspections and modifications. (See: \"Compliance: Forthwith\".)\n\nMechanics of implementation and discretion:\n\n- The AD does not include the technical steps in its text; it points to Boeing Service Bulletin No. 57-62 for the procedures. This makes compliance dependent on the content of that external manufacturer document and on maintenance organisations following it. (See: \"Document: Boeing SB No. 57-62\".)\n- The term \"forthwith\" limits discretion about when to act; the AD provides no staged or optional compliance schedule in the published text. (See: \"Compliance: Forthwith\".)\n\nTrade-offs, incentives and risks (source-grounded):\n\n- Incentives: Operators are incentivised to perform the inspection/modification promptly to comply with the AD. The AD channels technical remediation through the manufacturer service bulletin, creating an incentive to use the Boeing-prescribed method. (See: \"Document: Boeing SB No. 57-62\".)\n- Costs and opportunity cost: Immediate compliance may impose direct maintenance costs and short-term operational disruption (aircraft out of service while work is done). The AD text does not provide financial assistance or scheduling flexibility; those costs fall to operators/owners. (See: \"Applicability: All models\" and \"Compliance: Forthwith\".)\n- Compliance burden and implementation risk: Because the AD refers to an external service bulletin rather than including technical detail, operators must obtain and follow that bulletin; any ambiguity or delay in accessing or interpreting the bulletin could affect timely compliance. (See: \"Document: Boeing SB No. 57-62\".)\n\nWhat the directive does not specify (and therefore shifts to other documents or actors):\n\n- The AD text does not describe the technical inspection or modification steps, nor does it provide alternative means of compliance or an inspection interval — those details must be obtained from the referenced Boeing Service Bulletin. (See: \"Document: Boeing SB No. 57-62\".)\n- The AD does not state how compliance will be recorded, how long modified structure is acceptable before reinspection, or who certifies that the work has been completed; these operational details will be addressed through the service bulletin and standard maintenance certification procedures under the regulator's rules. (See: the overall structure of the AD and the reference to the service bulletin.)\n\nSource citations: the AD heading and the three explicit lines in the instrument are the authoritative source for the points above: \"Applicability: All models.\" \"Document: Boeing SB No. 57-62.\" \"Compliance: Forthwith.\""},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific airworthiness concern. It has not expanded beyond its original purpose of mandating inspection/modification of a particular structural component on a specific aircraft type."},"complexity_factors":["Extremely short document — only 3 substantive lines of regulatory text","No defined terms section — relies entirely on external Boeing document (SB 57-62) for technical details","No conditional logic or exceptions — blanket applicability to all Boeing 727 models","Single cross-reference only (to Boeing Service Bulletin)","Simple command structure: applicability + document reference + compliance deadline"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA).\n\n**What it does:**\nOrders owners and operators of **Boeing 727 aircraft** to inspect and modify a specific part called the \"inboard mid-flap link support beam.\" This is a structural component in the wing flap system.\n\n**Who it affects:**\nAnyone who owns or operates any model of Boeing 727 aeroplane in Australia.\n\n**Why it matters:**\nFlaps are crucial for takeoff and landing — they extend to increase wing area and lift at low speeds. If the support beam for the mid-flap links fails, it could compromise the aircraft's ability to control its flaps, potentially leading to loss of control during critical flight phases. This directive mandates immediate action (\"forthwith\") to prevent structural failure.\n\n**What must be done:**\nOperators must follow **Boeing Service Bulletin No. 57-62**, which contains the detailed inspection and modification instructions. The compliance deadline is immediate — there's no grace period."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-23-inboard-mid-flap-link-support-beam-inspection-and-modification","history":"/api/acts/ad-b727-23-inboard-mid-flap-link-support-beam-inspection-and-modification/history","analysis":"/api/acts/ad-b727-23-inboard-mid-flap-link-support-beam-inspection-and-modification/analysis","conflicts":"/api/acts/ad-b727-23-inboard-mid-flap-link-support-beam-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-b727-23-inboard-mid-flap-link-support-beam-inspection-and-modification/important-cases","documents":"/api/acts/ad-b727-23-inboard-mid-flap-link-support-beam-inspection-and-modification/documents"}}