{"id":"F2006B09776","name":"AD/F28/39 - Pilot and Passenger Seat Locking Mechanism - Inspection and Modification","slug":"ad-f28-39-pilot-and-passenger-seat-locking-mechanism-inspection-and-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54683,"registerId":"commonwealth-F2006B09776-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F28/39 - Pilot and Passenger Seat Locking Mechanism - 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)  Fokker F28 Series Aeroplanes\n\n \n\nAD/F28/39  Pilot and Passenger Seat Locking Mechanism - Inspection and Modification\n\n\n4/79\n\n \n\nApplicability: All model F28 aeroplanes fitted with “IPECO” Seats in pilot compartment or in locations other than pilot compartment.\n\n \n\nDocument: 1. RLD AD No. 79/05/25; or\n\n \n\n2. Fokker SB No. F28/25-82.\n\n \n\nCompliance: In accordance with requirement document No. 1 except that initial inspection shall be performed within 50 hours time in Service after 1 March 1979.\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":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive from 1979 addressing a specific mechanical defect. It has not expanded beyond its original narrow scope of seat locking mechanism inspection for Fokker F28 aircraft."},"complexity_factors":["Very short document (approximately 150 words)","Only 1 defined term implicitly referenced ('time in Service')","No cross-referencing to other legislation sections","Simple conditional logic: if aircraft has IPECO seats, then comply","Single compliance pathway with one timing exception","No nested exceptions or sub-delegations"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It applies to **Fokker F28 series aircraft** equipped with specific \"IPECO\" seats.\n\n**What it requires:**\n- **Inspection and modification** of the locking mechanisms on pilot and passenger seats\n- The work must follow Dutch aviation authority guidelines (RLD AD No. 79/05/25) or Fokker's own service bulletin (SB F28/25-82)\n- **Deadline:** The first inspection must happen within **50 hours of flying time** after 1 March 1979\n\n**Why it matters:**\nFaulty seat locking mechanisms could allow seats to move unexpectedly during flight — a serious safety risk, especially for pilots during critical phases like takeoff or landing. This directive forces operators to check and fix the problem before it causes an accident.\n\n**Who it affects:**\nAirlines and operators flying Fokker F28 aircraft with these specific seats."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The instrument as presented applies specifically to all F28 aeroplanes fitted with IPECO seats (Applicability) and directs compliance with an identified technical document (Document). The text does not indicate an expansion or narrowing of that applicability from an earlier version; it retains a focused scope limited to the specified aircraft and seat type and sets a specified compliance timing (Applicability; Document; Compliance)."},"complexity_factors":["Short, narrowly targeted directive text limited to one aircraft type and one seat maker (Applicability).","Technical procedures and detail are delegated to external documents (RLD AD No. 79/05/25; Fokker SB F28/25-82), requiring operators to obtain and interpret those documents (Document).","A specific historical timing requirement (initial inspection within 50 hours TIS after 1 March 1979) creates a clear but time‑bound compliance duty (Compliance).","Limited procedural content in the directive itself reduces internal complexity but increases dependence on the referenced materials for execution (Document; Compliance).","Potential ambiguity about which referenced document governs (the text lists two documents but instructs compliance in accordance with Document No. 1 except for the timing modification) (Document; Compliance).","Operational complexity for operators arises from scheduling downtime, labour and parts procurement, even though the regulatory text is concise (Document; Compliance)."],"plain_english_summary":"What this directive does (mechanical change)\n\n- Requires inspection and modification of the pilot and passenger seat locking mechanism on Fokker F28 aeroplanes that are fitted with \"IPECO\" seats in the pilot compartment or elsewhere on the aeroplane (Applicability).\n- The technical procedures to be followed are those set out in the referenced requirement documents: RLD AD No. 79/05/25 (Document No. 1) or Fokker Service Bulletin No. F28/25-82 (Document No. 2). The directive instructs compliance in accordance with Document No. 1, except that the initial inspection must be done within 50 hours time in service after 1 March 1979 (Document; Compliance).\n\nWho is affected\n\n- Aircraft owners and operators of Fokker F28 series aeroplanes that have IPECO seats in the pilot compartment or in any passenger locations (Applicability).\n- Maintenance organisations and technicians who must carry out the inspection and any required modifications according to the referenced documents (Document; Compliance).\n- Indirectly, pilots and passengers who use the seats covered by the directive.\n\nWho pays and who decides\n\n- The economic cost (inspection labour, any parts, and aircraft downtime) falls on the aircraft owner/operator because they must perform or fund the inspections and modifications (Compliance; Document).\n- The directive is issued as part of the Civil Aviation Safety Authority’s Schedule of Airworthiness Directives under the Civil Aviation Regulations (header), and it refers operators to the specified technical documents for the required work (Document).\n\nHow it works in practice\n\n- Operators must obtain the referenced requirement document (RLD AD No. 79/05/25) and carry out the inspection/modification steps set out there, except that the initial inspection deadline is explicitly set at 50 hours time in service after 1 March 1979 (Document; Compliance).\n- If operators prefer or need the alternate reference, Fokker SB No. F28/25-82 is listed as the other document option (Document).\n- The directive itself does not reproduce the step‑by‑step technical procedures; it mandates compliance with the referenced documents, so operators must consult those documents to know exactly what to inspect and what modifications are required (Document).\n\nStated purpose and how to evaluate it against costs and incentives\n\n- The directive text supplied does not include an explicit statement of the safety problem or rationale. The instrument nevertheless imposes a concrete obligation: inspect and modify specified seat locking mechanisms according to the referenced documents and timing (Document; Compliance).\n- Costs and incentives: the direct financial cost and operational burden (labour, parts, aircraft downtime) fall on owners/operators because they must perform the work. The operator has an incentive to schedule the work to minimise revenue loss (for example during other maintenance). The directive reduces an operator’s freedom to defer these inspections because it sets a regulatory compliance requirement and a specific initial-inspection deadline (Compliance).\n\nImplementation, compliance burden and discretion\n\n- The directive delegates technical detail to external documents (Document). That reduces ambiguity about methods only if operators obtain and follow those documents. The requirement to use Document No. 1 (with the timing exception) leaves limited room for technical discretion, but operators must interpret which document applies and obtain it (Document; Compliance).\n- Administrative and logistical burdens include sourcing the referenced documents, planning aircraft downtime, performing inspections, fitting any required modifications or replacement parts, and retaining records to demonstrate compliance to the regulator (Document; Compliance).\n\nTrade-offs and likely behavioural responses (concrete mechanisms)\n\n- Operators are likely to allocate resources to comply: obtain the requirements document, task maintenance crews, schedule aircraft out of service for inspection/modification, and purchase any specified parts. These are direct, measurable costs tied to compliance (Document; Compliance).\n- Benefits (not stated in the text) would be realised by operators, crew and passengers if the inspections/modifications reduce seat locking failures. The directive text itself does not quantify benefits or costs; it prescribes a compliance path instead (Document; Compliance).\n\nKey textual references\n\n- Applicability: identifies affected aeroplanes and seat types (Applicability).\n- Document: lists the two technical requirement documents to be followed, with Document No. 1 as the primary reference (Document).\n- Compliance: specifies that compliance is “in accordance with requirement document No. 1 except that initial inspection shall be performed within 50 hours time in Service after 1 March 1979” (Compliance).\n\nSummary statement\n\n- This airworthiness directive mandates that operators of Fokker F28 aeroplanes fitted with IPECO seats must inspect and, if necessary, modify pilot and passenger seat locking mechanisms by following specified technical documents, with an explicit deadline for the initial inspection. The regulatory obligation shifts the direct cost and operational burden of inspection and modification onto the aircraft owner/operator and requires reliance on the referenced documents for technical execution (Applicability; Document; Compliance)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f28-39-pilot-and-passenger-seat-locking-mechanism-inspection-and-modification","history":"/api/acts/ad-f28-39-pilot-and-passenger-seat-locking-mechanism-inspection-and-modification/history","analysis":"/api/acts/ad-f28-39-pilot-and-passenger-seat-locking-mechanism-inspection-and-modification/analysis","conflicts":"/api/acts/ad-f28-39-pilot-and-passenger-seat-locking-mechanism-inspection-and-modification/conflicts","importantCases":"/api/acts/ad-f28-39-pilot-and-passenger-seat-locking-mechanism-inspection-and-modification/important-cases","documents":"/api/acts/ad-f28-39-pilot-and-passenger-seat-locking-mechanism-inspection-and-modification/documents"}}