{"id":"F2006B08852","name":"AD/DC4/9 - Hydraulic Hand Pump - Modification","slug":"ad-dc4-9-hydraulic-hand-pump-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52051,"registerId":"commonwealth-F2006B08852-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DC4/9 - Hydraulic Hand Pump - 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)  Douglas DC4 Series Aeroplanes\n\n \n\nAD/DC4/9 Hydraulic Hand Pump - Modification NK\n\nDocument: 1. Douglas SB (DC4) No. 3 revised 8 June 1948; or\n\n \n\n2. FAA AD 47-2-6; or 3. ANO 105.1.16.2.5.8.\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":"On the face of the supplied text there is no indication the scope has been changed from an original intent: the AD requires a hydraulic hand pump modification for Douglas DC‑4 series aeroplanes and directs compliance to one of three specified documents (Douglas SB (DC4) No.3 rev. 8 June 1948; FAA AD 47‑2‑6; ANO 105.1.16.2.5.8). The text supplied neither adds nor narrows applicability beyond that requirement."},"complexity_factors":["Directive text is very short and delegates technical detail to external documents (Douglas SB, FAA AD, ANO), which reduces internal complexity but requires consulting multiple sources.","Applies to vintage airframes (Douglas DC‑4 series), creating practical complexity in parts availability and specialised labour.","Compliance requires coordination between operators, maintenance organisations and the regulator (administrative coordination complexity).","Enforcement and any alternative methods of compliance depend on regulatory discretion rather than explicit AD text.","Cross‑jurisdictional reference (FAA AD) may introduce interpretive differences for Australian operators."],"plain_english_summary":"What this instrument does, mechanically\n\n- AD/DC4/9 requires a modification of the hydraulic hand pump installed on Douglas DC‑4 series aeroplanes. The directive does not set out the modification steps in the text shown; instead it requires compliance by following one of the documents it lists: Douglas SB (DC4) No. 3 (rev. 8 June 1948), or FAA AD 47‑2‑6, or ANO 105.1.16.2.5.8. (See: AD/DC4/9; Documents 1–3.)\n\nWho this affects\n\n- Owners and operators of Douglas DC‑4 series aeroplanes, and the maintenance organisations or mechanics who service those aeroplanes, are the parties required to take action to implement the modification. The Civil Aviation Safety Authority (CASA) is the regulator that issues and enforces the airworthiness directive (AD/DC4/9).\n\nWhy it matters (official claim and how that claim translates into costs and incentives)\n\n- The directive’s title and placement in the Schedule of Airworthiness Directives indicate the measure is intended to address an airworthiness or safety concern relating to the hydraulic hand pump on DC‑4 aircraft. That is an attribution of purpose based on the AD’s nature and heading, not a statement of independent fact. (See: AD/DC4/9.)\n\n- Who pays: aircraft owners/operators pay for work, parts, and downtime required to carry out the modification specified in the referenced documents (AD/DC4/9; Documents 1–3).\n\n- Incentives created: operators must choose between installing the modification (incurring immediate cost and downtime) or following any alternative compliance paths approved by the regulator. Compliance preserves the aircraft’s approved airworthiness status; non‑compliance risks regulatory enforcement, grounding, or denial of certificate privileges.\n\n- Compliance burden and practical trade‑offs: the directive delegates the technical specification to external documents (the Douglas service bulletin, an FAA AD, or an ANO clause). This reduces textual length in the AD but requires operators to obtain and follow those external materials. For vintage aircraft like the DC‑4, the practical burdens may include locating parts, specialist labour, and scheduling work without excessive operational disruption. (See: AD/DC4/9; Documents 1–3.)\n\n- Administrative discretion and enforcement: CASA enforces compliance with the AD. The directive’s brief form leaves technical judgement—such as acceptable alternative methods of compliance or timing—to regulatory processes or to the content of the referenced documents, which concentrates technical discretion in regulators and approved maintenance authorities.\n\n- Effects on private choice and markets: the AD compels a specific technical modification, reducing operators’ freedom to leave the pump unchanged. Maintenance organisations, parts suppliers, and engineers who can perform the modification gain demand; operators face a direct cost. If parts or qualified technicians are scarce, this can raise prices and increase aircraft downtime.\n\nPotential implementation risks and substitution effects\n\n- Implementation risk arises from relying on historical documents (a 1948 service bulletin and a 1947 FAA AD are cited), including availability of parts and clarity of technical instructions. Operators may substitute responses to the AD by seeking alternative compliance methods, temporarily grounding affected aircraft, or retiring aircraft if modification costs exceed economic value.\n\nConcise mechanics summary\n\n- The AD imposes an obligation to modify the hydraulic hand pump on Douglas DC‑4 series aeroplanes by following one of the three listed documents. Operators pay for and arrange the work; CASA oversees compliance. (AD/DC4/9; Documents 1–3.)"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive focused specifically on hydraulic hand pump modifications for DC-4 aircraft. It has not expanded beyond its original technical safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","No defined terms section","No conditional logic or exceptions","Simple directive structure: issue identified, solution mandated, three alternative compliance documents cited","Single subject matter (one aircraft type, one component, one required action)","No cross-references to other legislation beyond the three technical source documents"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA) for **Douglas DC-4 series aircraft**.\n\n**What it does:**\n- Requires owners and operators of DC-4 aeroplanes to modify the **hydraulic hand pump** system on these aircraft.\n- The modification must be done according to one of three approved technical documents:\n  1. Douglas Service Bulletin (SB) No. 3, revised 8 June 1948; or\n  2. FAA Airworthiness Directive 47-2-6 (an American aviation safety rule); or\n  3. ANO 105.1.16.2.5.8 (an Australian National Order).\n\n**Who it affects:**\n- Anyone who owns, operates, or maintains Douglas DC-4 aircraft in Australia.\n\n**Why it matters:**\n- Airworthiness Directives are legally binding safety orders. If you don't comply, your aircraft cannot legally fly.\n- This particular AD addresses a safety issue with the hydraulic hand pump—a critical backup system used to operate landing gear, flaps, or brakes if the main hydraulic system fails. Without this modification, there could be a safety risk during flight operations."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dc4-9-hydraulic-hand-pump-modification","history":"/api/acts/ad-dc4-9-hydraulic-hand-pump-modification/history","analysis":"/api/acts/ad-dc4-9-hydraulic-hand-pump-modification/analysis","conflicts":"/api/acts/ad-dc4-9-hydraulic-hand-pump-modification/conflicts","importantCases":"/api/acts/ad-dc4-9-hydraulic-hand-pump-modification/important-cases","documents":"/api/acts/ad-dc4-9-hydraulic-hand-pump-modification/documents"}}