{"id":"F2006B04929","name":"AD/CESSNA 150/31 Amdt 3 - Vertical Fin Attach Brackets, Nutplates and Fittings","slug":"ad-cessna-150-31-amdt-3-vertical-fin-attach-brackets-nutplates-and-fittings","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":44774,"registerId":"commonwealth-F2006B04929-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 150/31 Amdt 3 - Vertical Fin Attach Brackets, Nutplates and Fittings","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCessna 150, F150, 152 & F152 Series Aeroplanes\n\nAD/CESSNA 150/31\n\nAmdt 3\n\n  \n\nVertical Fin Attach Brackets, Nutplates and Fittings\n\n  \n3/85\n\nApplicability: All models 150, A150, F150, FA150 and FRA150.\n\nAll model 152 with S/N 15279406 to 15284541. All model A152 with S/N A1520735 to A1520943.\n\nAll model F152 with S/N F15201429 to F15201808. All model FA152 with S/N FA1520337 to FA1520372.\n\nRequirement: 1. Inspect the attach bracket and nutplates using the method detailed in Cessna SIL No. SE 79-49, Rev. 1.\n\n2. a. Remove paint from both base radii on each of the port and starboard rear attach fittings.\n\nb. Visually check the radius area, inspecting for cracking and/or corrosion. If there are indications of either condition the brackets are to be replaced.\n\nc. Reprotect the subject area with an approved protective treatment.\n\nCompliance: Inspect within 100 hours time in service after 31 November 1984, and thereafter at intervals not exceeding 100 hours time in service.\n\nBackground: This amendment corrects the aircraft applicability so as to only include inspection of aircraft with the fabricated attach bracket.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1704},"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment narrowed the scope from previous versions. The Background explicitly states it 'corrects the aircraft applicability so as to only include inspection of aircraft with the fabricated attach bracket,' thereby excluding aircraft with cast or machined brackets that were likely covered in earlier amendments."},"complexity_factors":["External technical document reference (Cessna SIL No. SE 79-49) containing unstated inspection procedures","Precise serial number applicability requiring aircraft record cross-referencing","Technical aviation terminology (port/starboard, nutplates, fabricated brackets, time in service)","Multi-step procedural compliance (paint removal, inspection, conditional replacement, reprotection)"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of specified Cessna 150/152 serial-numbered aircraft to have the fabricated brackets that attach the vertical stabiliser inspected every 100 flight hours for cracking and corrosion, with paint removed from radii, damaged brackets replaced, and protective coating reapplied. It prevents catastrophic tail separation and loss of control. Amendment 3 narrows applicability to aircraft with fabricated attach brackets only."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-150-31-amdt-3-vertical-fin-attach-brackets-nutplates-and-fittings","history":"/api/acts/ad-cessna-150-31-amdt-3-vertical-fin-attach-brackets-nutplates-and-fittings/history","analysis":"/api/acts/ad-cessna-150-31-amdt-3-vertical-fin-attach-brackets-nutplates-and-fittings/analysis","conflicts":"/api/acts/ad-cessna-150-31-amdt-3-vertical-fin-attach-brackets-nutplates-and-fittings/conflicts","importantCases":"/api/acts/ad-cessna-150-31-amdt-3-vertical-fin-attach-brackets-nutplates-and-fittings/important-cases","documents":"/api/acts/ad-cessna-150-31-amdt-3-vertical-fin-attach-brackets-nutplates-and-fittings/documents"}}