{"id":"F2006B10446","name":"AD/HS 125/164 - Pitot/Static and Stall Vent Drain Valves","slug":"ad-hs-125-164-pitot-static-and-stall-vent-drain-valves","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116155,"registerId":"commonwealth-F2006B10446-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.png)  \nFor the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CAR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.","sortOrder":0},{"sectionNumber":"AD/HS 125/164 Pitot/Static and Stall Ven","sectionType":"part","heading":"AD/HS 125/164 Pitot/Static and Stall Vent Drain Valves 1/2001","content":"# AD/HS 125/164 Pitot/Static and Stall Vent Drain Valves 1/2001\n\nApplicability: Model DH.125, Model HS.125, Model BH.125, Model BAe.125, Model Hawker 800, Model Hawker 800XP, and Model Hawker 1000 series aeroplanes; as listed in Raytheon Aircraft Service Bulletin SB 34-3207, dated August 1999; excluding those aeroplanes on which all pitot/static drain vent valves have been modified with an insert in accordance with Raytheon Aircraft Repair Design Office instructions.\n\nRequirement: 1. Drain the pitot/static and stall vent drain valves, then perform a leak test of the systems, in accordance with SB 34-3207.\n\n    2. If, as a result of the Requirement 1 drain check, all drain valves are found to be operative, but any valve does not pass the leak test, accomplish one of the following actions:\n\n    apply a temporary seal of the drain valve(s) in accordance with Raytheon Aircraft SB 34-3223, dated August 1999; or\n\n    b. replace the drain valve components with new or serviceable drain valve components in accordance with SB 34-3207 and perform a leak test in accordance with SB 34-3207; or\n\n    c. modify the drain valves in accordance with Raytheon Aircraft SB 34-3282, dated August 1999.\n\nModification of ALL the drain valves in accordance with SB 34-3282 constitutes terminating action for the requirement to perform repetitive leak tests.\n\n    3. If any drain valve was sealed in accordance with Requirement 2.a., either Requirement 2.b. or 2.c. must be accomplished.\n\n    4. If, as a result of the Requirement 1 drain check, any drain valve is inoperative (eg. plugged or taped), whether or not any leaking is detected, disassemble the valve and clean all obstructions in accordance with SB 34-3207 and perform a general visual inspection for corrosion of the drain valve.","sortOrder":1}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — addressing a specific unsafe condition in pitot/static drain valves on a defined aircraft series. The multiple repair options (temporary seal, replacement, or permanent modification) represent alternative compliance paths rather than scope expansion."},"complexity_factors":["Multiple conditional branches in Requirements 2-4 (if/then logic for operative vs inoperative valves, leaking vs non-leaking)","Cross-references to three separate Service Bulletins (SB 34-3207, SB 34-3223, SB 34-3282) without reproducing their content","Nested requirements (Requirement 3 mandates completion of 2.b or 2.c if 2.a was used)","Specific exclusion clause for pre-modified aircraft requiring verification of modification standard","Terminating action concept (modification of ALL valves ends repetitive testing obligation)"],"plain_english_summary":"This CASA Airworthiness Directive orders owners/operators of specified British Aerospace/Raytheon business jets (HS.125 series and Hawker 800/1000) to inspect, drain, test and—if necessary—repair, replace or modify pitot/static and stall vent drain valves.  \n\nThe action prevents blocked or leaking valves that can cause false airspeed/altitude indications; a permanent modification (SB 34‑3282) removes the need for repeat testing."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The AD sets a self-contained applicability and requirements limited to the listed 125-series aeroplanes and excludes aircraft already modified per Raytheon instructions. The instrument does not, within the supplied text, indicate it alters or supersedes a prior AD; absent a prior-reference in this excerpt, there is no clear sign the scope has changed from earlier instruments."},"complexity_factors":["Multiple aircraft types listed in Applicability increases operator coverage and variation in fleet; see 'Applicability'.","Reliance on external Raytheon service bulletins (SB 34-3207, SB 34-3223, SB 34-3282) for the required procedures and acceptable corrective actions creates operational dependency on vendor documents; see 'Requirement' references.","Conditional branching of remedial options (temporary seal, replace components, or modify) requires decision-making by maintenance organisations and follow-up actions; see Requirement 2.a–2.c and Requirement 3.","Terminating action (modification of ALL drain valves) removes repetitive testing requirement, creating a one-off cost vs. ongoing test trade-off; see Requirement 2.c and note on terminating action.","Inspection and cleaning duty where valves are inoperative adds maintenance workload and potential parts/repair costs; see Requirement 4.","The AD is issued under CASA's delegated power (subregulation 39.1(1) of CAR 1998), indicating administrative discretion over issuance and compliance timing; see introductory paragraph.","Compliance timing is referenced but not shown in this excerpt (the AD refers to a compliance section), increasing implementation uncertainty for operators without the full AD text."],"plain_english_summary":"**What it does:** Requires operators of specified DH/HS/BH/BAe/Hawker 125‑series aircraft to drain and leak‑test pitot/static and stall vent drain valves using Raytheon service bulletins, and to seal, repair/replace, or modify valves depending on test results; modification of all valves ends repetitive testing.  \n\n**Who it affects and why it matters:** Affects aircraft owners, maintenance organisations and pilots by imposing inspections, possible parts/replacement and modification costs; CASA (the delegate) sets compliance timing and relies on Raytheon SBs for procedures."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-164-pitot-static-and-stall-vent-drain-valves","history":"/api/acts/ad-hs-125-164-pitot-static-and-stall-vent-drain-valves/history","analysis":"/api/acts/ad-hs-125-164-pitot-static-and-stall-vent-drain-valves/analysis","conflicts":"/api/acts/ad-hs-125-164-pitot-static-and-stall-vent-drain-valves/conflicts","importantCases":"/api/acts/ad-hs-125-164-pitot-static-and-stall-vent-drain-valves/important-cases","documents":"/api/acts/ad-hs-125-164-pitot-static-and-stall-vent-drain-valves/documents"}}