{"id":"F2006B09676","name":"AD/F27/107 - Inboard Aileron Hinge Bolt Retention - Inspection and Replacement","slug":"ad-f27-107-inboard-aileron-hinge-bolt-retention-inspection-and-replacement","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115815,"registerId":"commonwealth-F2006B09676-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F27/107 - Inboard Aileron Hinge Bolt Retention - Inspection and Replacement","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)  Fokker F27 Series Aeroplanes\n\n \n\n# AD/F27/107  Inboard Aileron Hinge Bolt Retention - Inspection and Replacement\n\nApplicability: All model F27 with S/Nos. 10105 to 10635. Document:  Fokker SB F27/57-58.\n\nNote: RLD AD BLA 83-20-57 refers.\n\n \n\nCompliance: Before 1st January 1984.\n\n# 8/83\n\n \n\nBackground: Restricted aileron movement was reported due to migration of hinge bolt and bush.\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":2,"scope_assessment":{"changed":false,"description":"The directive’s scope, as expressed in the text, is consistent with its stated purpose: it targets a specific mechanical fault (migration of hinge bolt and bush) on a clearly defined set of aircraft (Fokker F27 S/Ns 10105–10635) and prescribes inspection and replacement in line with the manufacturer service bulletin. The text contains no provisions that expand or narrow that scope beyond the stated applicability, compliance deadline, and reference to the service bulletin and related AD (Applicability; Background; Document; Compliance; Note)."},"complexity_factors":["Narrow applicability limited to Fokker F27 with S/Ns 10105–10635 (Applicability), reducing scope of subjects affected.","Single, fixed compliance deadline (before 1 January 1984) simplifies temporal compliance requirements (Compliance).","Substantive technical procedure is not set out in the directive itself but delegated to an external service bulletin (Fokker SB F27/57-58), requiring implementers to obtain and follow additional documentation (Document).","Directive references another airworthiness directive (RLD AD BLA 83-20-57), introducing cross-reference complexity for full compliance checks (Note).","The directive states a clear mechanical fault to address (migration of hinge bolt and bush) so the failure mode is specified, reducing interpretive ambiguity (Background).","Enforcement and penalty mechanisms are not specified in the text provided, leaving practical compliance monitoring to regulatory processes outside the directive text."],"plain_english_summary":"What this directive does, mechanically:\n\n- It requires inspection of the inboard aileron hinge bolt retention on certain Fokker F27 aeroplanes and replacement of affected parts where necessary. (Applicability; Document)\n- The technical steps for inspection and any replacement are to be carried out in accordance with the manufacturer service bulletin identified (Fokker SB F27/57-58). (Document)\n- The requirement applied to aircraft with serial numbers 10105 to 10635 and had to be complied with before 1 January 1984. (Applicability; Compliance)\n\nWhy this requirement is stated: the directive records that a restricted aileron movement was observed, caused by migration of the hinge bolt and its bush. The directive therefore directs inspection and replacement to address that specific mechanical failure mode. (Background)\n\nWho this affects and who pays:\n\n- Affected parties are operators/owners of Fokker F27 aircraft with S/Ns 10105–10635. (Applicability)\n- Those operators bear the practical costs: arranging inspections, performing any required removal and replacement of hinge bolts/bushes, labour and parts as required by the service bulletin. (Document; Compliance)\n\nWho decides and what discretion exists:\n\n- The Civil Aviation Safety Authority issued the directive specifying the obligation and deadline. (Compliance)\n- The directive refers implementers to the Fokker service bulletin for the technical procedure, so detailed workmanship and parts specification decisions are delegated to the manufacturer’s guidance rather than set out in the text of the directive itself. (Document)\n\nHow behaviour must change:\n\n- Operators must inspect the specified hinge retention before the compliance date and replace components if migration or deterioration is found. (Compliance; Document)\n- If operators do not perform the inspection/replacement, the aircraft would remain non-compliant with the directive and continue to carry the mechanical defect the directive identifies. (Background)\n\nCosts, incentives and trade-offs (mechanisms, not judgements):\n\n- Direct compliance costs: time off-line for each aircraft to inspect and, if needed, to replace hinge bolts/bushes; cost of replacement parts and labour. (Document; Compliance)\n- Incentive structure: operators have a direct safety and regulatory incentive to perform the inspection and replacement because the directive sets a mandatory compliance deadline and cites a specific safety defect (restricted aileron movement). (Background; Compliance)\n- Opportunity cost: maintenance resources and hangar time allocated to this work cannot be used elsewhere during compliance. (Compliance)\n\nImplementation risks and compliance burden:\n\n- The directive does not contain step-by-step repair instructions in its text; it relies on the referenced service bulletin for technical detail. Operators must obtain and follow that bulletin to meet the directive. That creates a dependence on the manufacturer’s documentation for correct implementation. (Document)\n- The directive specifies a fixed deadline for compliance, which concentrates demand for maintenance resources ahead of that date and may create scheduling pressure for affected operators. (Compliance)\n\nCross-references and enforcement note:\n\n- The directive notes a related RLD AD (BLA 83-20-57), indicating cross-references to other authority or jurisdictional actions that implementers may need to consult. (Note)\n\nSummary statement of purpose claim and its concrete implications:\n\n- The directive’s stated purpose is to prevent restricted aileron movement caused by migration of hinge bolts and bushes. Mechanically, that is achieved by mandating inspection and replacement where necessary, applied to a defined fleet subset and enforced by a compliance deadline; operators must incur the inspection and repair work and follow the manufacturer service bulletin to satisfy the requirement. (Background; Applicability; Document; Compliance)\n"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical defect in a defined aircraft population. It has not expanded beyond its original purpose of mandating inspection and replacement of a single component to prevent aileron malfunction."},"complexity_factors":["Extremely short document (approximately 150 words)","Only one defined applicability criterion (serial number range)","Single compliance deadline with no conditional extensions","No cross-references to other legislation beyond a single service bulletin and related foreign directive","No nested exceptions or conditional logic","Straightforward imperative language ('inspect and replace')","Single technical issue addressed with clear causal link to safety risk"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for aircraft.\n\n**What it does:**\n- Requires owners and operators of specific **Fokker F27 aircraft** (serial numbers 10105 to 10635) to inspect and replace the **inboard aileron hinge bolt retention** components.\n\n**Why it matters:**\n- A safety problem was discovered where the hinge bolt and bush could **migrate (move out of position)**, causing **restricted aileron movement**. Ailerons are the hinged surfaces on the wings that control the aircraft's roll — if they don't move properly, the pilot can't control the plane effectively, creating a serious flight safety risk.\n\n**Who must comply:**\n- Anyone operating the affected Fokker F27 models must complete this inspection and replacement **before 1 January 1984**.\n\n**Key reference:**\n- Operators must follow the technical instructions in **Fokker Service Bulletin F27/57-58** to carry out the work."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f27-107-inboard-aileron-hinge-bolt-retention-inspection-and-replacement","history":"/api/acts/ad-f27-107-inboard-aileron-hinge-bolt-retention-inspection-and-replacement/history","analysis":"/api/acts/ad-f27-107-inboard-aileron-hinge-bolt-retention-inspection-and-replacement/analysis","conflicts":"/api/acts/ad-f27-107-inboard-aileron-hinge-bolt-retention-inspection-and-replacement/conflicts","importantCases":"/api/acts/ad-f27-107-inboard-aileron-hinge-bolt-retention-inspection-and-replacement/important-cases","documents":"/api/acts/ad-f27-107-inboard-aileron-hinge-bolt-retention-inspection-and-replacement/documents"}}