{"id":"F2006B03475","name":"AD/BAe 146/22 - Stall Ident and Warning","slug":"ad-bae-146-22-stall-ident-and-warning","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43029,"registerId":"commonwealth-F2006B03475-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/22 - Stall Ident and Warning","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 146/22 Stall Ident and Warning 10/90\n\nApplicability: BAe 146 models 200 and 200A S/No E 2012 and subsequent with modification HCM 00503B embodied before delivery, or retrofitted by SB 27-94-00503B.\n\n \n\nRequirement: Action in accordance with British Aerospace SB 27-109-00503C.\n\n \n\nNote: UK CAA Mandatory SB.\n\n \n\nCompliance: Prior to 31 August 1991.\n\n \n\nBackground: The stall identification summing unit Part No C81606-3 has incorrect speed law.\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\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted airworthiness directive addressing a specific technical defect in a specific aircraft component. It has not expanded beyond its original purpose of mandating a safety-critical modification to the stall warning system."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 2 defined applicability criteria (model type and serial number range)","Single requirement referencing an external technical document (SB 27-109-00503C)","No nested exceptions or conditional logic","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Straightforward compliance deadline with no alternative methods or phased implementation"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** issued by Australia's Civil Aviation Safety Authority (CASA) that mandates a safety fix for specific British Aerospace BAe 146 aircraft.\n\n**What it does:**\n- Requires owners/operators of certain BAe 146-200 and 200A aircraft to carry out a modification to the **stall warning system** — the equipment that alerts pilots when the plane is flying too slowly and at risk of stalling (losing lift).\n\n**Who it affects:**\n- BAe 146-200 and 200A aircraft with serial numbers E 2012 and onwards\n- Only those that have a specific modification called \"HCM 00503B\" installed (either from the factory or added later via Service Bulletin SB 27-94-00503B)\n\n**The problem:**\n- The **stall identification summing unit** (a component that calculates when to trigger the stall warning) — part number C81606-3 — has an \"incorrect speed law.\" This means the device uses the wrong mathematical formula to determine airspeed thresholds, potentially giving pilots incorrect or delayed warnings about an impending stall.\n\n**What must be done:**\n- Follow the instructions in British Aerospace Service Bulletin SB 27-109-00503C to fix the issue.\n\n**Deadline:**\n- The fix must be completed **before 31 August 1991**.\n\n**Why it matters:**\n- Stall warnings are critical safety systems. An incorrect speed law could mean pilots don't get timely warnings, increasing the risk of an aerodynamic stall — a dangerous condition where the wings stop generating enough lift. This directive ensures affected aircraft are corrected before they pose a safety risk."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD's scope is limited to BAe 146 models 200 and 200A with S/No E 2012 and subsequent that have the specified modification embodied or retrofitted by SB 27-94-00503B, and it requires the corrective action in SB 27-109-00503C to be completed by 31 August 1991. There is no indication in the AD text that the scope differs from its original stated intent to correct the stall identification summing unit's incorrect speed law (see \"Applicability\", \"Requirement\", \"Compliance\", \"Background\")."},"complexity_factors":["Narrow technical scope limited to specific airframe models and serial numbers (Applicability).","Mandated compliance with an external manufacturer service bulletin (Requirement) rather than detailing corrective steps inside the AD.","A fixed compliance deadline that requires scheduling maintenance (Compliance).","Technical root cause stated succinctly (incorrect speed law of a named part) but the detailed fix is contained in the referenced SB (Background).","Cross-reference to another authority's mandatory bulletin (UK CAA note) which adds a layer of regulatory context."],"plain_english_summary":"This AD requires owners/operators of BAe 146-200/200A aeroplanes (SN E2012 onward with HCM 00503B or retrofit SB 27-94-00503B) to modify the stall identification/warning summing unit per British Aerospace SB 27-109-00503C to correct an incorrect speed law. Compliance is mandatory before 31 August 1991. Operators bear the costs and downtime; the directive eliminates discretion by mandating the SB-prescribed fix to restore correct equipment performance."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-22-stall-ident-and-warning","history":"/api/acts/ad-bae-146-22-stall-ident-and-warning/history","analysis":"/api/acts/ad-bae-146-22-stall-ident-and-warning/analysis","conflicts":"/api/acts/ad-bae-146-22-stall-ident-and-warning/conflicts","importantCases":"/api/acts/ad-bae-146-22-stall-ident-and-warning/important-cases","documents":"/api/acts/ad-bae-146-22-stall-ident-and-warning/documents"}}