{"id":"F2006B08842","name":"AD/DC4/35 - Floor Beam to Rear Spar Frame Attachment Angle - Inspection","slug":"ad-dc4-35-floor-beam-to-rear-spar-frame-attachment-angle-inspection","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":52319,"registerId":"commonwealth-F2006B08842-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/DC4/35 - Floor Beam to Rear Spar Frame Attachment Angle - Inspection","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/DC4/35 Floor Beam to Rear Spar Frame NK\n\nAttachment Angle - Inspection\n\nDocument: 1. Douglas SB (DC4) No. 102; or\n\n \n\n2. ANO 105.1.16.2.6.4.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive of the type routinely issued for vintage aircraft. It has not expanded beyond its original purpose of addressing a specific structural inspection requirement for the DC-4 fleet."},"complexity_factors":["Extremely short document — essentially a title and two document references","No defined terms section","No conditional logic or exceptions","No cross-references to other legislation beyond the two cited technical documents","Single, specific mechanical requirement with clear compliance path (inspect per Service Bulletin)","Assumes technical aviation knowledge but presents minimal legal complexity"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** for **Douglas DC-4 series aircraft** — a specific safety order issued by Australia's Civil Aviation Safety Authority (CASA).\n\n**What it does:**\n- Requires inspection of a specific structural component: the **attachment angle** that connects the **floor beam** to the **rear spar frame**\n- This is a mandatory safety check to ensure the airframe remains structurally sound\n\n**Who it affects:**\n- Owners and operators of Douglas DC-4 series aeroplanes (a vintage four-engine propeller aircraft, also known as the C-54 Skymaster in military service)\n- Maintenance organisations servicing these aircraft\n\n**Why it matters:**\n- The attachment angle is critical to the aircraft's structural integrity. If it fails, it could compromise the fuselage structure and flight safety\n- Compliance is **legally mandatory** under the Civil Aviation Regulations 1998\n- The directive references two technical documents that provide the detailed inspection procedures:\n  - **Douglas Service Bulletin (SB) No. 102** — the manufacturer's official maintenance instruction\n  - **ANO 105.1.16.2.6.4** — an Airworthiness Notice Order (likely the UK or Australian equivalent standard)\n\n**In short:** If you operate a DC-4, you must inspect this specific bracket where the floor connects to the rear wing structure, following the manufacturer's specified procedure."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The supplied AD text is a short instruction that delegates inspection requirements to Douglas SB (DC4) No. 102 or ANO 105.1.16.2.6.4. There is no information in the supplied text indicating a change of scope from any prior or original instrument; the AD simply references the two documents for detailed requirements."},"complexity_factors":["References external technical documents (Douglas SB No. 102; ANO 105.1.16.2.6.4) for all inspection detail, increasing reliance on non‑embedded material.","AD text omits procedural specifics (intervals, methods, acceptance criteria, corrective actions), requiring consultation of other sources.","Technical subject matter (structural attachment angle on floor beam/rear spar frame) requires specialised inspection skills and possibly parts/repair work.","Regulatory placement under Civil Aviation Regulations 1998, Part 39 (Schedule of Airworthiness Directives) creates legal effect but the supplied extract is minimal.","Potential ambiguity for operators about responsibility for costs, certification and enforcement because those points are not stated in the supplied text."],"plain_english_summary":"This AD requires inspection of the floor‑beam to rear‑spar‑frame attachment angle on Douglas DC‑4 series aeroplanes and mandates compliance by following either Douglas Service Bulletin (DC4) No. 102 or ANO 105.1.16.2.6.4. The AD itself contains no procedural details, assignment of responsibilities, cost or enforcement rules—those are in the referenced documents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-dc4-35-floor-beam-to-rear-spar-frame-attachment-angle-inspection","history":"/api/acts/ad-dc4-35-floor-beam-to-rear-spar-frame-attachment-angle-inspection/history","analysis":"/api/acts/ad-dc4-35-floor-beam-to-rear-spar-frame-attachment-angle-inspection/analysis","conflicts":"/api/acts/ad-dc4-35-floor-beam-to-rear-spar-frame-attachment-angle-inspection/conflicts","importantCases":"/api/acts/ad-dc4-35-floor-beam-to-rear-spar-frame-attachment-angle-inspection/important-cases","documents":"/api/acts/ad-dc4-35-floor-beam-to-rear-spar-frame-attachment-angle-inspection/documents"}}