{"id":"F2006B04959","name":"AD/CESSNA 170/28 - Wing Strut Attachment Strap","slug":"ad-cessna-170-28-wing-strut-attachment-strap","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44832,"registerId":"commonwealth-F2006B04959-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 170/28 - Wing Strut Attachment Strap","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)  Cessna 170, 172, F172, FR172 and 175 Series Aeroplanes\n\n \n\nAD/CESSNA 170/28 Wing Strut Attachment Strap 9/73\n\nApplicability: All model 172 with S/No. 17261664 to 17261808. Requirement:  Action in accordance with Cessna SL SE 73-20.\n\nCompliance: Within 100 hours time in service after 24 September 1973.\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":1,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive from 1973. It has not expanded beyond its original narrow purpose of addressing a specific manufacturing defect in a limited serial number range of Cessna 172 aircraft."},"complexity_factors":["Extremely short document (under 150 words)","No defined terms section","No cross-references to other legislation beyond a single manufacturer service letter","Simple conditional logic: single applicability criterion (serial number range) and single compliance deadline","No exceptions, exemptions, or nested conditions","Single-purpose instrument: one aircraft type, one defect, one required action"],"plain_english_summary":"**What this is:** This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it like a compulsory recall notice, but for aircraft instead of cars.\n\n**What it does:** It requires owners and operators of specific Cessna aeroplanes to inspect or fix a problem with the **wing strut attachment strap** — the metal component that helps hold the wing to the fuselage. A faulty strap could cause the wing to detach in flight, which would obviously be catastrophic.\n\n**Who it affects:** Owners and operators of **Cessna 172 model aircraft with serial numbers 17261664 through 17261808** (a specific production batch).\n\n**What must be done:** The aircraft must be inspected and repaired according to **Cessna Service Letter SE 73-20** (a technical bulletin from the manufacturer) within **100 hours of flying time** after 24 September 1973.\n\n**Why it matters:** This AD addresses a critical structural defect. Non-compliance means the aircraft cannot legally fly in Australian airspace. Ignoring it risks wing failure and loss of life."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive’s scope is explicit and confined to the stated serial number range and to the action described in Cessna SL SE 73-20 (Applicability; Requirement). The text provides no indication that the statutory or factual scope has been expanded or narrowed from any earlier statement; it simply imposes the manufacturer-specified action on the identified aircraft within a defined compliance period (Compliance)."},"complexity_factors":["Narrow technical scope limited to a single component (wing strut attachment strap).","Applicability restricted to a short, specific block of serial numbers (17261664–17261808).","Core technical steps are delegated to an external document (Cessna SL SE 73-20), requiring retrieval and interpretation of that service letter.","Short, fixed compliance window (100 hours after 24 September 1973) creates a scheduling constraint for operators.","No procedural detail in the directive itself (inspection/repair specifics, parts, or labour) increases dependence on the referenced service letter."],"plain_english_summary":"This directive mandates inspection/repair of the wing strut attachment strap on Cessna Model 172s serials 17261664–17261808 by following Cessna Service Letter SE 73-20. Owners/operators must complete the work within 100 hours TIS from 24 September 1973 and bear the cost. It creates an immediate, time‑limited maintenance demand and depends on access to the referenced service letter for technical details and parts/labour requirements."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-170-28-wing-strut-attachment-strap","history":"/api/acts/ad-cessna-170-28-wing-strut-attachment-strap/history","analysis":"/api/acts/ad-cessna-170-28-wing-strut-attachment-strap/analysis","conflicts":"/api/acts/ad-cessna-170-28-wing-strut-attachment-strap/conflicts","importantCases":"/api/acts/ad-cessna-170-28-wing-strut-attachment-strap/important-cases","documents":"/api/acts/ad-cessna-170-28-wing-strut-attachment-strap/documents"}}