{"id":"F2006B04583","name":"AD/BELL 212/51 - Fin To Tail Boom Junction","slug":"ad-bell-212-51-fin-to-tail-boom-junction","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114317,"registerId":"commonwealth-F2006B04583-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BELL 212/51 - Fin To Tail Boom Junction","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)  \nBell Helicopter Textron 212 Series Helicopters\n\nAD/BELL 212/51 Fin To Tail Boom Junction 8/92\n\nTX\n\nApplicability: All models.\n\nRequirement: Remove the tail boom lower elliptical inspection panel, (Part number 205-030-814- 019) and perform a close visual inspection of the internal tail boom to fin junction area, paying particular attention to:\n\n    1) Skin Part number 212-030-099-087 or \\-131, in the internal radius adjacent to, and the area immediately forward of, angle Stiffener Part number 205-030-801-007. (See attached diagram, Item 22).\n\n    2) The flanges of the left and right hand upper boom longerons, in the area adjacent to angle Stiffener Part number 205-030-801-007. (See attached diagram, Item 21).\n\nCompliance: At the earliest opportunity, but before further flight after 25 May 92.\n\nBackground: One operator of a Bell 212 has reported a 250 mm crack in the subject skin, and adjacent cracks in the upper left hand longeron. These cracks occurred in line with the forward edge of the gear box support mount, and progressed under the skin doubler (Part number 212-030-099-089 or \\-129, Item 23 ) making external detection difficult. This one-off inspection is required to ensure that no other helicopters are immediately affected. Further action may be expected following laboratory investigation or manufacturers recommendation.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1720},"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope as a one-off emergency inspection requirement issued in response to a specific reported structural defect."},"complexity_factors":["References 6 specific aircraft part numbers requiring technical manual cross-referencing","Depends on attached diagrams (Item 21, 22, 23) not reproduced in the legislative text","Technical aviation terminology (longerons, stiffeners, doublers, elliptical inspection panels)","Nested compliance deadline ('earliest opportunity' constrained by 'before further flight' hard cutoff)"],"plain_english_summary":"This is an **emergency safety inspection order** for anyone operating Bell 212 helicopters. It requires an immediate check for dangerous cracks where the tail fin connects to the tail boom.\n\n**What you must do:**\n- Remove a specific inspection panel on the lower tail boom (part number 205-030-814-019)\n- Visually inspect the internal junction area, specifically looking for cracks in:\n  - The skin panel (parts 212-030-099-087 or -131) near a support bracket\n  - The top support beams (\"longerons\") on both left and right sides\n\n**Why this matters:**\nOne operator discovered a 250mm crack hidden under a reinforcement plate (doubler) that couldn't be seen from outside. Cracks in this area could cause the tail to fail in flight.\n\n**When to comply:**\nImmediately — before the next flight after 25 May 1992.\n\n**Who is affected:**\nAll models of Bell Helicopter Textron 212 series helicopters."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bell-212-51-fin-to-tail-boom-junction","history":"/api/acts/ad-bell-212-51-fin-to-tail-boom-junction/history","analysis":"/api/acts/ad-bell-212-51-fin-to-tail-boom-junction/analysis","conflicts":"/api/acts/ad-bell-212-51-fin-to-tail-boom-junction/conflicts","importantCases":"/api/acts/ad-bell-212-51-fin-to-tail-boom-junction/important-cases","documents":"/api/acts/ad-bell-212-51-fin-to-tail-boom-junction/documents"}}