{"id":"F2006B03482","name":"AD/BAe 146/30 - Lower Wing Skin","slug":"ad-bae-146-30-lower-wing-skin","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43036,"registerId":"commonwealth-F2006B03482-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/30 - Lower Wing 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 146/30 Lower Wing Skin 4/91\n\nApplicability: Model 146 with Constructor’s Numbers:\n\n \n\nE2133, E3134, E3135, E3137, E2139, E3141, E3142, E3145, E2148, E3151 and E3155.\n\n \n\nRequirement: Action in accordance with Mandatory BAe 146 SB 57-36.\n\n \n\nCompliance: As specified in the Requirement Document but with a revised effectivity date of 18 April 1991 for Australian registered aircraft.\n\n \n\nBackground: Production inspection records cannot confirm that chamfering of the edge of the inner skin was carried out during aircraft build.\n\n \n\nFretting of an unchamfered skin edge against the inner face of the outer butt strap could lead to an increase in stresses on the 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","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD does not expand the set of affected aircraft or alter the corrective action; it enforces Mandatory SB 57-36 for the listed constructor's numbers and only revises the effectivity date for Australian-registered aircraft (Compliance)."},"complexity_factors":["Narrow applicability: targets a limited set of constructor's numbers (Applicability).","Single technical remedy: mandates actions specified in one Mandatory Service Bulletin (Requirement).","Dependence on external document: technical steps and schedules are in BAe 146 SB 57-36, which operators must obtain and follow (Requirement/Compliance).","Administrative adjustment only: revises effectivity date for Australian-registered aircraft without expanding affected fleet (Compliance).","Operational implementation: requires physical inspection/possible repair work, parts and workshop scheduling (implicit from Background and Requirement).","Evidence uncertainty: based on incomplete production records about chamfering, creating inspection-driven risk management (Background)."],"plain_english_summary":"This Airworthiness Directive requires owners/operators of certain BAe 146 aeroplanes (identified by constructor’s numbers) to carry out the inspection and corrective actions set out in Mandatory BAe 146 Service Bulletin 57-36, with an Australian effectivity date of 18 April 1991. The measure responds to missing chamfering on an inner wing skin edge that can cause fretting and increased stress on the outer butt strap. Operators must obtain the Service Bulletin, fund and arrange inspections/repairs, and certify compliance to the regulator."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific manufacturing defect in a limited fleet. It has not expanded beyond its original purpose of mandating a single safety inspection/repair."},"complexity_factors":["Single, specific applicability limited to 11 identified aircraft by constructor number","Only one substantive requirement: compliance with an external technical document (BAe SB 57-36)","No defined terms section — all language is technical aviation terminology assumed known to the audience","No conditional logic, exceptions, or nested provisions","Single compliance date with straightforward modification for Australian context","Extremely short document (approximately 150 words of substantive content)","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:**\nOrders owners and operators of certain British Aerospace BAe 146 aircraft to inspect and fix a manufacturing defect in the lower wing skin.\n\n**Who it affects:**\n- **11 specific aircraft** identified by their constructor's numbers (E2133, E3134, E3135, E3137, E2139, E3141, E3142, E3145, E2148, E3151, and E3155)\n- Australian-registered BAe 146 Model 146 aircraft only\n\n**The safety problem:**\nDuring manufacturing, the edge of the inner wing skin may not have been properly **chamfered** (beveled/smoothed) as required. Without this chamfer, the skin edge can rub (**fret**) against an outer metal strap (**butt strap**). This rubbing increases stress on the strap, potentially leading to structural failure.\n\n**What must be done:**\nOperators must follow the instructions in **BAe Service Bulletin 57-36** — a technical repair notice from the manufacturer. For Australian aircraft, the deadline is **18 April 1991**.\n\n**Why it matters:**\nWing structural failures can be catastrophic. This directive prevents potential accidents by catching a manufacturing oversight before it causes damage."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-30-lower-wing-skin","history":"/api/acts/ad-bae-146-30-lower-wing-skin/history","analysis":"/api/acts/ad-bae-146-30-lower-wing-skin/analysis","conflicts":"/api/acts/ad-bae-146-30-lower-wing-skin/conflicts","importantCases":"/api/acts/ad-bae-146-30-lower-wing-skin/important-cases","documents":"/api/acts/ad-bae-146-30-lower-wing-skin/documents"}}