{"id":"F2006B10449","name":"AD/HS 125/167 - Turbine Air Discharge and Water Separator Ducts","slug":"ad-hs-125-167-turbine-air-discharge-and-water-separator-ducts","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116161,"registerId":"commonwealth-F2006B10449-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/167 - Turbine Air Discharge and Water Separator Ducts","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)  \n![](image.002.png)  \nBritish Aerospace BAe 125 Series Aeroplanes\n\nAIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\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.\n\n![](image.003.png)AD/HS 125/167 Turbine Air Discharge and Water Separator Ducts\n\n  \n5/2002\n\nDM\n\nApplicability: Model BAe 125 800A, 1000A, and 1000B series aeroplanes, and Hawker 800 aeroplanes, up to and including serial number 258406; and Hawker 800XP series aeroplanes, up to and including serial number 258483, and 1000 series aeroplanes.\n\nRequirement: 1. For Model BAe.125 series 800A series aeroplanes; Hawker 800 aeroplanes up to and including serial number 258406; and Hawker 800XP series aeroplanes up to and including serial number 258459:\n\nUnless accomplished previously, remove the clamps, bedding tapes, and rubber connecting sleeves at the ends of the air turbine discharge duct and the water separator, and replace the clamps and rubber connecting sleeves with new, improved components, in accordance with the Accomplishment Instructions of Raytheon Service Bulletin SB 21-3377, Revision 1, dated July 2000.\n\n2. For Model Hawker 800XP series aeroplanes having serial numbers 258460 to 258483; Model BAe.125 series 1000A/1000B aeroplanes; and Hawker 1000 series aeroplanes:\n\nUnless accomplished previously, remove the aluminium bedding strips from the air conditioning duct sleeves attached to both ends of the turbine air discharge duct and at the outlet end of the water separator, in accordance with the Accomplishment Instructions of Raytheon Service Bulletin SB 21-3414, Revision 1, dated July 2000.\n\nPrevious action and Terminating action:\n\nFor certain aeroplanes, actions described in the original issue of Raytheon Service Bulletin SB 21-3377 may have been accomplished prior to the effective date of this Airworthiness Directive and are not required to be repeated. However, any action described in Raytheon Service Bulletin SB 21-3377, Revision 1, dated July 2000; or Raytheon Service Bulletin SB 21-3414, Revision 1, dated July 2000, that has not been accomplished on those aeroplanes must be accomplished in accordance with this Airworthiness Directive. Accomplishment of the actions specified in both Raytheon Service Bulletin SB 21-3377, Revision 1, dated July 2000; and Raytheon Service Bulletin SB 21-3414, Revision 1, dated July 2000, is terminating action for the requirements of this Airworthiness Directive.\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.004.png)Note: FAA AD 2001-13-05 refers.\n\nCompliance: For Requirement 1 and 2: Within 100 hours time-in-service or, two months after the effective date of this Airworthiness Directive, whichever occurs first.\n\nThis Airworthiness Directive becomes effective on 10 April 2002.\n\nBackground: The manufacturer reported that air conditioning clamps and connecting sleeves that connect the water separator and turbine discharge duct have come loose. Should either of these ducts become disconnected, it will result in loss of air supply to maintain adequate cabin pressure. Loss of adequate cabin pressure at high altitude would require emergency procedures to be used, such as use of oxygen, auxiliary pressurisation, or emergency descent. This Airworthiness Directive therefore requires the replacement of existing clamps, bedding tapes and sleeves with new improved components that will prevent clamp slippage and subsequent duct disconnection.\n\n![](image.005.png)  \n\nEugene Paul Holzapfel\n\nDelegate of the Civil Aviation Safety Authority 28 March 2002\n\n![](image.002.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 10 April 2002.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"A positive credit balance is required for all requests, including BYOK, so fallback providers remain available. Add credits at https://vercel.com/d?to=%2F%5Bteam%5D%2F%7E%2Fai%3Fmodal%3Dtop-up to continue.","source":"analysis-cron"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive implements the manufacturer's corrective measures for a reported hardware slippage problem and limits requirements to listed models and serial-number ranges. It does not expand applicability beyond those aircraft, nor introduce recurring inspections; completion of the specified service bulletins is stated as the terminating action for this AD."},"complexity_factors":["Multiple affected types and serial-numbered sub-ranges (Applicability) add eligibility checking for operators","Two distinct corrective actions depending on model/serial (Requirement 1 & 2)","Reliance on external manufacturer Service Bulletins (Raytheon SB 21-3377 Rev1 and SB 21-3414 Rev1) for technical instructions","Terminating action tied to accomplishment of both service bulletins (Previous action and Terminating action)","Short compliance window (100 hours TIS or two months) requiring scheduling in operational fleets (Compliance)","Safety rationale linked to pressurisation loss if ducts disconnect (Background)","Reference to an FAA AD for related action (Note/Background) that may require cross-jurisdictional tracking"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of specific BAe 125 / Hawker 800 and 1000 series aeroplanes (limited by model and serial number) to replace or modify turbine air discharge and water-separator duct clamps, bedding strips and sleeves following Raytheon service bulletins. CASA issued the directive to prevent duct disconnection that could cause loss of cabin pressure. Operators pay for parts and labour and must complete the work within 100 flight hours or two months, and record compliance per the service instructions."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This AD maintains focused scope on the specific unsafe condition (duct clamp failures) described in the background. The applicability sections precisely target affected aircraft by serial number without expanding beyond the original safety issue."},"complexity_factors":["Multiple applicability categories based on aircraft model and serial number ranges (4 distinct groups)","Two different technical requirements depending on aircraft configuration (SB 21-3377 vs SB 21-3414)","Cross-references to external technical documents (Raytheon Service Bulletins) for detailed instructions","Conditional compliance logic (100 hours OR 2 months, whichever first)","Previous action provisions allowing credit for work done before the AD effective date","Terminating action clause specifying when the safety requirement is satisfied"],"plain_english_summary":"This CASA safety order mandates urgent repairs to specified BAe 125 and Hawker 800/800XP/1000 series aircraft to prevent cabin depressurisation caused by loose air‑conditioning duct clamps/sleeves. Affected owners/operators must install improved clamps/sleeves (per SB 21‑3377) or remove aluminium bedding strips (per SB 21‑3414), depending on model/serial number. Compliance is mandatory within 100 flight hours or 2 months (whichever is first) from April 2002 to eliminate a known in‑flight depressurisation hazard."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-167-turbine-air-discharge-and-water-separator-ducts","history":"/api/acts/ad-hs-125-167-turbine-air-discharge-and-water-separator-ducts/history","analysis":"/api/acts/ad-hs-125-167-turbine-air-discharge-and-water-separator-ducts/analysis","conflicts":"/api/acts/ad-hs-125-167-turbine-air-discharge-and-water-separator-ducts/conflicts","importantCases":"/api/acts/ad-hs-125-167-turbine-air-discharge-and-water-separator-ducts/important-cases","documents":"/api/acts/ad-hs-125-167-turbine-air-discharge-and-water-separator-ducts/documents"}}