{"id":"F2006B07214","name":"AD/SWSA226/71 - Wing Lower Skin at WS 187","slug":"ad-swsa226-71-wing-lower-skin-at-ws-187","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":48987,"registerId":"commonwealth-F2006B07214-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SWSA226/71 - Wing Lower Skin at WS 187","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/SWSA226/71 Wing Lower Skin at WS 187 5/95\n\nApplicability: Metro III, Model SA227-AC S/N 415, 416, 420 - 554 and Merlin IVC, Model SA227-AT, S/N 423 \\- 554 without either reinforcement doublers 27K31013-001, 27K31013-002 or stringer ties 27-13869 installed.\n\nRequirement: 1. Do a fluorescent dye penetrant inspection of the wing lower surface skin in the area of Wing Station (WS) 187.0. Inspect in accordance with Fairchild Service Bulletin (SB) 227-57-002, Revision dated 23 January 1984, Accomplishment Instructions, paragraph IIA and CAO 108.10.\n\n    2. Install reinforcement doublers 27K31013-001 LH and 27K31013-002 RH, in accordance with Fairchild SB227-57-002, Revision dated 23 January 1984, Accomplishment Instructions, paragraph IIB; or,\n\n    3. Install stringer ties 27-13869 in accordance with Fairchild SB 227-57-002, Revision dated 23 January 1984, Accomplishment Instructions paragraph IIC.\n\nNote: FAA AD 95-01-07 refers.\n\nCompliance: 1. Inspect in accordance with Requirement 1 before 20 hours time in service after 27 April 1995.\n\nRe-inspect at intervals not to exceed 50 hours time in service, until modified.\n\n2. Modify in accordance with either Requirement 2 or 3 before 500 hours time in service after 27 April 1995.\n\nBackground: Due to the configuration of the wing lower surface access panels, cracking is expected to occur at WS 187 between the two access openings. The inspections required by this AD will allow timely detection of cracking. Modification will terminate the requirement for further inspections.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD applies narrowly to the listed aircraft without the listed reinforcements and imposes inspection and modification obligations; the instrument does not purport to broaden applicability beyond those models/SNs or change other regulatory categories."},"complexity_factors":["Narrow applicability: specific models and serial number ranges (Metro III SA227‑AC S/N 415–554; Merlin IVC SA227‑AT S/N 423–554)","Conditional application: only applies where specified reinforcement doublers (27K31013‑001/‑002) or stringer ties (27‑13869) are not installed","Cross‑references to external technical documents: Fairchild Service Bulletin 227‑57‑002 (23 Jan 1984) and CAO 108.10 required for inspection/modification procedures","Multiple compliance options: either install reinforcement doublers or stringer ties to terminate inspections","Specific and short compliance timeframes: initial inspection before 20 hours TIS after 27 Apr 1995, re‑inspect every 50 hours until modification, modification required before 500 hours TIS","Operational burden: inspections require fluorescent dye‑penetrant technique and access to parts and maintenance capability","Termination mechanism: modification explicitly terminates the inspection requirement, creating clear but binary compliance outcome","Reference to foreign regulator action (FAA AD 95‑01‑07) adds an interjurisdictional compliance context"],"plain_english_summary":"This Airworthiness Directive requires fluorescent dye‑penetrant inspections of the wing lower skin at Wing Station 187 on specified Fairchild (Swearingen) SA226/SA227 Metro III and Merlin IVC aeroplanes that do not already have certain reinforcement doublers or stringer ties. Operators must either inspect on a short schedule and re‑inspect until modification, or install the specified reinforcement doublers or stringer ties within a set flight‑hour limit to stop the inspections. The measure is intended to detect and address cracking between two access openings."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific structural defect in specific aircraft. It has not expanded beyond its original purpose of mandating inspection and repair of wing lower skin cracking at WS 187."},"complexity_factors":["Single, specific aircraft type and limited serial number range (narrow applicability)","Three clear alternative compliance paths (inspect-only pending modification, or two different modification options)","Precise reference to external technical documents (Fairchild Service Bulletin 227-57-002, CAO 108.10, FAA AD 95-01-07)","Defined compliance intervals tied to 'time in service' (flight hours) rather than calendar dates","No nested exceptions or conditional logic — straightforward if/then structure","Short document (approximately 250 words) with minimal defined terms"],"plain_english_summary":"This CASA Airworthiness Directive applies to certain Fairchild Metro III and Merlin IVC aircraft (specific serials) that lack a required wing reinforcement. It mandates fluorescent dye-penetrant inspections under the wing at Wing Station 187, repeated every 50 flight hours until a permanent repair is fitted.\n\nWithin 20 flight hours after 27 April 1995 the first inspection is required, and the fix—either doublers or stringer ties—must be installed within 500 flight hours to prevent crack growth and possible structural failure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-swsa226-71-wing-lower-skin-at-ws-187","history":"/api/acts/ad-swsa226-71-wing-lower-skin-at-ws-187/history","analysis":"/api/acts/ad-swsa226-71-wing-lower-skin-at-ws-187/analysis","conflicts":"/api/acts/ad-swsa226-71-wing-lower-skin-at-ws-187/conflicts","importantCases":"/api/acts/ad-swsa226-71-wing-lower-skin-at-ws-187/important-cases","documents":"/api/acts/ad-swsa226-71-wing-lower-skin-at-ws-187/documents"}}