{"id":"F2006B04953","name":"AD/CESSNA 170/2 - Right Wing Rear Spar","slug":"ad-cessna-170-2-right-wing-rear-spar","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44823,"registerId":"commonwealth-F2006B04953-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 170/2 - Right Wing Rear Spar","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 170/2 Right Wing Rear Spar NK Applicability:  Model 170B with S/Nos. 27107 to 27124. Model 172 with S/Nos 28675 to 28815. Requirement:  Action in accordance with Cessna SL No 170/172-6.\n\nCompliance:   Before 1 September 1971.\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":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1651},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This airworthiness directive remains tightly scoped to its original purpose: addressing a specific structural defect in the right wing rear spar of identified Cessna 170B and 172 aircraft. The scope has not expanded beyond this specific safety issue."},"complexity_factors":["Single, specific mechanical component addressed","No defined terms or interpretation section","Applicability determined by simple aircraft model and serial number ranges","Single external reference to manufacturer service letter","No conditional exceptions or nested requirements"],"plain_english_summary":"**What this does:** Orders owners of specific Cessna aircraft to inspect or repair the right wing rear spar (the main structural beam running through the back of the wing) to prevent potential structural failure.\n\n**Who it affects:** Owners and operators of:\n- **Cessna Model 170B** aircraft with serial numbers 27107 through 27124\n- **Cessna Model 172** aircraft with serial numbers 28675 through 28815\n\n**What must be done:** Follow the technical instructions in **Cessna Service Letter No. 170/172-6** regarding the right wing rear spar.\n\n**Deadline:** The required action had to be completed before **1 September 1971**.\n\n**Why it matters:** Wing spar failures can cause the wing to separate from the aircraft in flight. This directive ensures these specific high-risk aircraft receive necessary structural inspections or repairs to prevent catastrophic accidents."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-170-2-right-wing-rear-spar","history":"/api/acts/ad-cessna-170-2-right-wing-rear-spar/history","analysis":"/api/acts/ad-cessna-170-2-right-wing-rear-spar/analysis","conflicts":"/api/acts/ad-cessna-170-2-right-wing-rear-spar/conflicts","importantCases":"/api/acts/ad-cessna-170-2-right-wing-rear-spar/important-cases","documents":"/api/acts/ad-cessna-170-2-right-wing-rear-spar/documents"}}