{"id":"F2006B06932","name":"AD/SEATS/4 - Historical and Ex-Military Aircraft - Harness Attachment","slug":"ad-seats-4-historical-and-ex-military-aircraft-harness-attachment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114819,"registerId":"commonwealth-F2006B06932-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SEATS/4 - Historical and Ex-Military Aircraft - Harness Attachment","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 - 107 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Seats and Berths\n\n \n\n# AD/SEATS/4  Historical and Ex-Military Aircraft - Harness Attachment\n\nApplicability: All aircraft operated under an historical and ex- military Permit-To-Fly.\n\n# 12/88\n\n \n\nRequirement: 1. Inspect seat belt and harness attachments to ensure that they are connected to metal structure - either seat or airframe.\n\n \n\n2. If the attachment is to non-metal structure, modify the harness attachments to a scheme acceptable to the Authority.\n\n \n\nCompliance: Before each issue of Permit-To-Fly.\n\n \n\nBackground: During a forced landing of an ex-military aircraft, the seat belt separated from the crew seat which was manufactured from a type of phenol formaldehyde reinforced material.\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 directive applies to the same population described in the instrument (all aircraft operated under an historical and ex-military Permit-To-Fly) and imposes inspection and modification requirements prior to each Permit-To-Fly issue (Applicability; Requirement 1–2; Compliance). There is no indication in the text provided that the scope has been broadened or narrowed from its stated content."},"complexity_factors":["Narrow applicability limited to aircraft operated under an historical and ex-military Permit-To-Fly (Applicability) — reduces scope complexity.","Simple, binary technical requirement: attachments must be to metal structure, otherwise be modified (Requirement 1–2) — lowers legal complexity.","Recurrent compliance timing: must be satisfied before each issue of Permit-To-Fly (Compliance) — adds operational burden and administrative repetition.","Technical execution complexity for modifications: some seats use non-metallic materials (Background); engineering or specialised fittings may be required — adds practical/technical complexity.","Administrative discretion: modifications must follow a scheme acceptable to the Authority (Requirement 2) — introduces approval processes and potential for delay or differing outcomes.","Enforcement/verification implied but not detailed: the directive sets the check and acceptance requirement but does not prescribe documentation or inspection standards — creates modest implementation ambiguity."],"plain_english_summary":"Operators of historical and ex‑military aircraft flown under a Permit‑To‑Fly must, before each permit issue, inspect crew seat‑belt and harness attachment points and ensure they attach to metal structure or are modified to a method acceptable to the Civil Aviation Safety Authority. Introduced after a seat‑belt separation in a forced landing, the rule shifts recurring inspection and any modification costs and approval burden onto operators, with possible downtime and approval delays."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific known failure mode in a narrow class of aircraft. It has not expanded beyond its original purpose of ensuring harness attachments are structurally sound in historical military aircraft."},"complexity_factors":["Extremely short: only 2 substantive requirements","No defined terms section","No cross-references to other legislation or regulations","Simple conditional logic (if non-metal → then modify)","Single applicability criterion (historical/ex-military Permit-To-Fly)","Plain language throughout with minimal aviation jargon"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority. It applies to **historical and ex-military aircraft** that operate under a special 'Permit-To-Fly' rather than a standard airworthiness certificate.\n\n**What it requires:**\n- **Inspection:** Before each Permit-To-Fly is issued, someone must check that seat belts and harnesses are attached to **metal structure** (either the seat itself or the aircraft frame).\n- **Modification:** If any harness is attached to non-metal material (like plastic or composite), it must be re-engineered to a design approved by the aviation regulator.\n\n**Why it exists:**\nAn ex-military aircraft crashed during a forced landing when the pilot's seat belt ripped away from the seat. The seat was made from **phenol formaldehyde** (an early plastic/resin material) that couldn't withstand the forces of impact. This rule prevents that deadly failure from happening again.\n\n**Who must comply:**\nOwners and operators of vintage military aircraft flying under historical permits—not regular commercial or private planes."}},"importantCases":[],"_links":{"self":"/api/acts/ad-seats-4-historical-and-ex-military-aircraft-harness-attachment","history":"/api/acts/ad-seats-4-historical-and-ex-military-aircraft-harness-attachment/history","analysis":"/api/acts/ad-seats-4-historical-and-ex-military-aircraft-harness-attachment/analysis","conflicts":"/api/acts/ad-seats-4-historical-and-ex-military-aircraft-harness-attachment/conflicts","importantCases":"/api/acts/ad-seats-4-historical-and-ex-military-aircraft-harness-attachment/important-cases","documents":"/api/acts/ad-seats-4-historical-and-ex-military-aircraft-harness-attachment/documents"}}