{"id":"F2006B07226","name":"AD/SWSA226/83 - Wing Trailing Edge Ribs","slug":"ad-swsa226-83-wing-trailing-edge-ribs","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":49036,"registerId":"commonwealth-F2006B07226-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SWSA226/83 - Wing Trailing Edge Ribs","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)  \nFairchild (Swearingen) SA226 and SA227 Series Aeroplanes\n\nAD/SWSA226/83 Wing Trailing Edge Ribs 6/98\n\nApplicability: Models Serial Numbers\n\nSA226-TC TC201 through TC379\n\nSA226-T T201 through T275, and T277 through T291 SA226-T(B) T(B)276, and T(B)292 through T(B)378 SA226-AT AT001 through AT069\n\nRequirement: Inspect both wing trailing edge ribs at the centre flap actuator attach brackets, wing stations 98.385 and 100.635, for cracks in accordance with the Accomplishment Instructions section, Part A, of Fairchild Aircraft Service Bulletin (SB) 57-016, issued 25 June 1981, revised 9 December 1981.\n\nIf no cracks are found, install the reinforcement doubler, part number 27K36075-7, in accordance with the Accomplishment Instructions section, Part B of Fairchild SB 57- 016.\n\nIf any cracks are found, replace any cracked rib with a new rib assembly, part number 27-31085-1/2 or 27-31086-1/2, and install the new reinforcement doubler, part number 27K36075-7, in accordance with the Accomplishment Instructions section, Part B and Part C of Fairchild SB 57-016.\n\nNote: FAA AD 98-04-05 Amdt 39-10318 refers.\n\nCompliance: Unless already accomplished, within 500 hours time in service after 21 May 1998.\n\nThis airworthiness directive becomes effective on 21 May 1998.\n\nBackground: Fatigue cracking of the wing trailing edge ribs has been reported. Failure of a wing trailing edge rib could result in asymmetrical flap deflection with possible loss of control of the aircraft.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This airworthiness directive maintains its original narrow scope: addressing a specific structural fatigue issue in defined aircraft models. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single specific technical requirement with clear conditional branches (no cracks vs cracks found)","References external technical document (Fairchild Service Bulletin 57-016) for detailed instructions rather than reproducing them","Precise part numbers and serial number ranges specified (reduces ambiguity but requires cross-checking)","Limited cross-references (one note referencing corresponding FAA directive)","Straightforward compliance deadline (500 hours time in service)","No nested exceptions or complex defined terms"],"plain_english_summary":"This safety order requires owners/operators of certain Fairchild Swearingen SA226/SA227 series aeroplanes (specified serial ranges) to inspect wing trailing-edge ribs near the flap attachments for fatigue cracks and correct defects within 500 flight hours after 21 May 1998. If no cracks are found, install a reinforcement doubler; if cracked, replace the rib and install the doubler. The measure prevents possible flap asymmetry and loss of control and parallels FAA AD 98-04-05."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive implements inspections and mandatory repairs only for the listed serial numbers to address reported fatigue cracking of trailing edge ribs (Background; Applicability; Requirement). There is no indication within the text that the directive widens or narrows scope beyond correcting the reported defect; it prescribes specific technical remedies and a fixed compliance timeframe (Requirement; Compliance)."},"complexity_factors":["Narrow, serial‑numbered applicability limits which aircraft are affected (Applicability).","Prescriptive technical actions reference manufacturer's Service Bulletin for inspection, reinforcement and replacement steps (Requirement; SB 57‑016).","Specified part numbers for doubler and replacement ribs create procurement and inventory obligations (Requirement).","Short, hard compliance window (500 hours) imposes scheduling pressure on operators (Compliance).","No delegated discretion or alternative means provided; compliance is mandatory and process‑driven (Requirement; Compliance)."],"plain_english_summary":"This airworthiness directive requires owners/operators of specific Fairchild (Swearingen) SA226/227 serial numbers (Applicability) to inspect wing trailing‑edge ribs at the flap actuator attach brackets and, if clear, fit a reinforcement doubler or, if cracked, replace the rib assembly and fit the doubler as specified in Fairchild Service Bulletin 57‑016 (Requirement). Compliance is mandatory within 500 hours after 21 May 1998 (Compliance). Operators pay for the inspections, parts and replacements; the measure aims to prevent asymmetrical flap deflection from rib failure (Background)."},"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/ad-swsa226-83-wing-trailing-edge-ribs","history":"/api/acts/ad-swsa226-83-wing-trailing-edge-ribs/history","analysis":"/api/acts/ad-swsa226-83-wing-trailing-edge-ribs/analysis","conflicts":"/api/acts/ad-swsa226-83-wing-trailing-edge-ribs/conflicts","importantCases":"/api/acts/ad-swsa226-83-wing-trailing-edge-ribs/important-cases","documents":"/api/acts/ad-swsa226-83-wing-trailing-edge-ribs/documents"}}