{"id":"F2006B03490","name":"AD/BAe 146/4 Amdt 1 - Flight Controls - Stall Identification","slug":"ad-bae-146-4-amdt-1-flight-controls-stall-identification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43044,"registerId":"commonwealth-F2006B03490-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BAe 146/4 Amdt 1 - Flight Controls - Stall Identification","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)  \nBritish Aerospace BAe 146 Series Aeroplanes\n\nAD/BAe 146/4\n\nAmdt 1\n\n  \nFlight Controls \\- Stall Identification 1/87\n\nApplicability: Series 100 and 100A, and Series 200 and 200A, fitted with the suspect valves identified in the Requirement Document.\n\nRequirement: Action in accordance with British Aerospace Service Bulletin 27-58.\n\nNote: SB 27-58 supersedes SB 27-53.\n\nCompliance: Inspect within 60 flights after 2 May 1986 and thereafter at intervals not exceeding 60 flights until replaced with modified valve.\n\nFor spares prior to installation in an aircraft and thereafter a intervals not exceeding 60 flights until replaced with modified valve.\n\nBackground: A number of stick push valves in service may become defective as a result of internal corrosion within the solenoid assembly. This could lead to a dormant failure not apparent on the flight deck.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspections and replacements of corroded stick push valves."},"complexity_factors":["Very short document — approximately 150 words","Only 1 defined term implicitly referenced ('suspect valves' in the Requirement Document)","Single compliance pathway with clear timeframes (60 flights)","No nested exceptions or conditional logic","No cross-references to other legislation beyond the parent Civil Aviation Regulations 1998","Straightforward applicability criteria (specific aircraft series + specific component)","Single technical reference to British Aerospace Service Bulletin 27-58"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) that requires specific repairs or inspections on aircraft.\n\n**What it does:**\nOrders owners and operators of certain British Aerospace BAe 146 aircraft to inspect a critical flight control component called the \"stick push valve.\" This valve is part of the stall protection system — it automatically pushes the control column forward to prevent the aircraft from stalling (losing lift and potentially crashing).\n\n**The problem:**\nSome of these valves can develop internal corrosion that causes a \"dormant failure\" — meaning the valve could fail silently without any warning to the pilots. If the stall protection system fails without anyone knowing, the aircraft could stall unexpectedly with no automatic recovery.\n\n**Who must act:**\n- Owners/operators of BAe 146 Series 100, 100A, 200, and 200A aircraft\n- Only those fitted with specific \"suspect valves\" identified in the accompanying technical document\n\n**What they must do:**\n- Inspect the valves within 60 flights after 2 May 1986\n- Continue inspecting every 60 flights thereafter\n- Keep inspecting until the valve is replaced with a modified, corrosion-resistant version\n- Also inspect any spare valves before installing them in an aircraft, then every 60 flights until replaced\n\n**Why it matters:**\nThis is a life-safety measure. A failed stall protection system on a commercial airliner could lead to catastrophic loss of control. The directive forces operators to find and fix the problem before it causes an accident."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"This instrument is labelled as Amendment 1 and updates the requirement by directing compliance with British Aerospace Service Bulletin 27-58, which supersedes SB 27-53 (Note). The amendment specifies the inspection interval (within 60 flights after 2 May 1986 and every 60 flights thereafter) and explicitly extends the inspection requirement to spares prior to installation and thereafter until the valve is replaced with the modified unit (Compliance; For spares). Those changes alter the operational scope by (a) formalising the inspection cadence and (b) covering spare parts as well as in-service valves."},"complexity_factors":["Cross-reference to an external technical document (British Aerospace Service Bulletin 27-58) which contains the procedural detail (Requirement; Note)","Repeated, time-based compliance obligation (every 60 flights) applying both to in-service items and spares (Compliance; For spares)","Limited applicability tied to specific aircraft series and to those \"fitted with the suspect valves\" (Applicability)","Operational dependence on availability and installation of a \"modified valve\" to terminate recurring inspections (Compliance)","Safety-technical subject matter (internal corrosion of solenoid assembly) that requires maintenance/engineering competence to detect and remediate (Background)"],"plain_english_summary":"Operators and maintainers of BAe 146 Series 100/100A and 200/200A aircraft fitted with certain “suspect” stick‑push valves must inspect those valves per British Aerospace Service Bulletin 27‑58 within 60 flights of 2 May 1986 and every 60 flights thereafter until the valve is replaced by the modified unit; the same requirement applies to spares before installation. \n\nThe directive responds to possible internal corrosion causing dormant stall‑identification failures; operators bear inspection and replacement costs, creating an incentive to fit the modified valve to avoid repeated checks."}},"importantCases":[],"_links":{"self":"/api/acts/ad-bae-146-4-amdt-1-flight-controls-stall-identification","history":"/api/acts/ad-bae-146-4-amdt-1-flight-controls-stall-identification/history","analysis":"/api/acts/ad-bae-146-4-amdt-1-flight-controls-stall-identification/analysis","conflicts":"/api/acts/ad-bae-146-4-amdt-1-flight-controls-stall-identification/conflicts","importantCases":"/api/acts/ad-bae-146-4-amdt-1-flight-controls-stall-identification/important-cases","documents":"/api/acts/ad-bae-146-4-amdt-1-flight-controls-stall-identification/documents"}}