{"id":"F2006B03493","name":"AD/BAe 146/42 - Wing Centre Section Top Skin","slug":"ad-bae-146-42-wing-centre-section-top-skin","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43047,"registerId":"commonwealth-F2006B03493-current","compilationNumber":null,"startDate":"2026-04-01","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/42 - Wing Centre Section Top Skin","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)  British Aerospace BAe 146 Series Aeroplanes\n\n \n\nAD/BAe 146/42 Wing Centre Section Top Skin 4/92\n\nApplicability: All Series 146 aircraft pre mod HCM 00851C.\n\n \n\nRequirement: Action in accordance with Mandatory BAe 146 Service Bulletin SB 57-41, dated 26 July 1991.\n\n \n\nCompliance: Inspect before achieving 24 000 flights and then at intervals not exceeding 9 000 flights.\n\n \n\nBackground:  Recent results from the manufacturer’s airframe structural test program have indicated that cracking should be expected in both the LH and RH upper wing skin panels, beneath the upper centre line butt strap.\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":1398},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope focused solely on mandatory inspections for wing centre section top skin cracking on specific BAe 146 aircraft models."},"complexity_factors":["Single operative requirement referencing an external technical standard (Service Bulletin SB 57-41)","Clear numerical compliance thresholds (24,000 and 9,000 flight cycles)","Limited applicability criteria (specific aircraft series and modification status)","No nested exceptions or conditional logic"],"plain_english_summary":"**What this does:** This directive orders airlines and aircraft operators to inspect the top skin of the centre wing section on British Aerospace BAe 146 aircraft for cracks.\n\n**Who it affects:** Operators of all BAe 146 Series aircraft that haven't been modified according to service bulletin HCM 00851C.\n\n**What must be done:**\n- Follow the specific inspection instructions in British Aerospace Service Bulletin SB 57-41 (dated 26 July 1991)\n- Complete the first inspection before the aircraft reaches 24,000 flights\n- Repeat the inspection at least every 9,000 flights thereafter\n\n**Why it matters:** The manufacturer discovered during structural testing that cracks are likely to develop in the left and right upper wing skin panels, specifically beneath a structural join called the 'upper centre line butt strap'. If left unchecked, this could compromise the structural integrity of the wings."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-42-wing-centre-section-top-skin","history":"/api/acts/ad-bae-146-42-wing-centre-section-top-skin/history","analysis":"/api/acts/ad-bae-146-42-wing-centre-section-top-skin/analysis","conflicts":"/api/acts/ad-bae-146-42-wing-centre-section-top-skin/conflicts","importantCases":"/api/acts/ad-bae-146-42-wing-centre-section-top-skin/important-cases","documents":"/api/acts/ad-bae-146-42-wing-centre-section-top-skin/documents"}}