{"id":"F2006B04760","name":"AD/BN-2/49 - Pilots Seat Backs - Inspection and Modification","slug":"ad-bn-2-49-pilots-seat-backs-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44524,"registerId":"commonwealth-F2006B04760-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BN-2/49 - Pilots Seat Backs - 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)  Pilatus Britten-Norman BN-2 Series Aeroplanes\n\n \n\nAD/BN-2/49 Pilots Seat Backs - Inspection and Modification 7/84\n\nApplicability: All models with individual pilots sliding seat units - P/N NBC-010-H-001 (LH) and P/N NBC-010-H-002 (RH) or NBC-012-H-001, not embodying mod. NB/M/1217.\n\n \n\nDocument: Britten Norman SB No. BN2/SB163.\n\n \n\nCompliance: INSPECT: Prior to the issue of the next maintenance release after 31 July 1984 and\n\nthereafter at each issue of a new maintenance release.\n\n \n\nMODIFY: Before 30 November 1984.\n\n \n\nBackground: Some individual seat units, installed in the flight compartment, have been affected by distortion and fracture at the attachment of the folding back to the seat frame.\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 directive, as written, sets a focused scope: inspect and modify specific pilot seat units unless they already embody modification NB/M/1217. The text does not indicate any change to that original scope; it consistently limits applicability to the listed part numbers and exempts seats with mod NB/M/1217. (Applicability)"},"complexity_factors":["Narrow technical scope limited to specific seat part numbers and an existing mod exemption (NB/M/1217) which simplifies applicability.","Clear, short compliance schedule with two defined actions (inspect at maintenance releases; modify by a fixed date).","Dependence on an external detailed service bulletin (BN2/SB163) for technical execution increases operational detail but not legal complexity.","Temporal constraints (specific deadlines tied to maintenance-release events) create scheduling complexity for operators.","No alternative compliance options or tolerances are provided in the text, reducing procedural complexity but increasing operational pressure."],"plain_english_summary":"This directive requires operators of Pilatus Britten‑Norman BN‑2 aeroplanes fitted with specific individual pilot sliding seat units (certain P/Ns, unless already modified by NB/M/1217) to inspect those seats for distortion/fracture and to carry out a mandated seat‑back modification per Britten Norman SB BN2/SB163.  \n\nInspections must begin at the next maintenance release after 31 July 1984 and continue at each release; the modification must be completed by 30 November 1984. Operators bear costs and scheduling responsibility."},"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 specific aircraft type. It has not expanded beyond its original purpose of mandating seat inspections and modifications."},"complexity_factors":["Single, specific technical requirement (seat inspection and modification)","Only 4 defined part numbers in applicability section","Clear, absolute deadlines (31 July 1984 for first inspection, 30 November 1984 for modification)","No nested exceptions or conditional logic — compliance is straightforward","Short document (approximately 150 words of substantive content)","Single cross-reference to manufacturer service bulletin (Britten Norman SB No. BN2/SB163)","Binary applicability test (either the seat has the mod or it doesn't)"],"plain_english_summary":"This is an **Airworthiness Directive** (a mandatory safety order) issued by Australia's Civil Aviation Safety Authority for **Pilatus Britten-Norman BN-2 series aircraft** (small twin-engine planes commonly used for regional transport and island hopping).\n\n**What it requires:**\n- **Inspection:** Operators must check the pilots' sliding seat units for damage before the next maintenance release (a certificate allowing the plane to fly) issued after 31 July 1984, and then again at every subsequent maintenance release.\n- **Modification:** The seats must be physically modified before 30 November 1984.\n\n**Why it matters:**\nSome pilot seats were experiencing **distortion and fractures** where the folding seat back attaches to the frame. This is a serious safety issue — if a seat back fails during flight, the pilot could lose control of the aircraft or be injured.\n\n**Who must comply:**\nAll BN-2 aircraft with specific seat part numbers (NBC-010-H-001, NBC-010-H-002, or NBC-012-H-001) that haven't already been modified under service bulletin NB/M/1217.\n\n**The bottom line:** This directive forces operators to fix a potentially dangerous seat defect through regular inspections and a one-time modification, preventing possible accidents caused by seat failure in the cockpit."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bn-2-49-pilots-seat-backs-inspection-and-modification","history":"/api/acts/ad-bn-2-49-pilots-seat-backs-inspection-and-modification/history","analysis":"/api/acts/ad-bn-2-49-pilots-seat-backs-inspection-and-modification/analysis","conflicts":"/api/acts/ad-bn-2-49-pilots-seat-backs-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-bn-2-49-pilots-seat-backs-inspection-and-modification/important-cases","documents":"/api/acts/ad-bn-2-49-pilots-seat-backs-inspection-and-modification/documents"}}