{"id":"F2006L01020","name":"AD/HS 125/178 - Air Conditioning - Fan Venturi Motor","slug":"ad-hs-125-178-air-conditioning-fan-venturi-motor","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":58294,"registerId":"commonwealth-F2006L01020-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"British Aerospace BAe 125 Series Aeropla","sectionType":"division","heading":"British Aerospace BAe 125 Series Aeroplanes","content":"### British Aerospace BAe 125 Series Aeroplanes\n\n| AD/HS 125/178 | Air Conditioning - Fan Venturi Motor | 5/2006 |\n| ------------- | ------------------------------------ | ------ |\n\n| Applicability: | Raytheon Model DH.125, HS.125 and BH.125 series aeroplanes; Model BAe.125 Series 800A (C-29A and U-125), 800B, 1000A and 1000B aeroplanes; Model Hawker 800 (including variant U-125A) and 1000 aeroplanes all identified in Raytheon Service Bulletin SB 21-3669, dated December 2004. |\n| -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n| Requirement:   | 1. If not previously accomplished, carry out either of the flowing actions in accordance with the Accomplishment Instructions of Raytheon Service Bulletin SB 21-3669:                                                                                                                  |\n|                | a. Modify the existing fan venturi part number (P/N) 132322-2-1 by installing an improved motor, P/N 207640-34.                                                                                                                                                                         |\n|                | b. Replace the existing fan venturi P/N 132322-2-1 with a new fan venturi P/N 132322-3-1.                                                                                                                                                                                               |\n|                | Note 1: Raytheon Service Bulletin SB 21-3669 refers to Honeywell Service Bulletin 132322-21-4041, Revision 2, dated 20 August 2004, as an additional source of service information for doing the modification. The Raytheon service bulletin includes the Honeywell service bulletin.   |\n|                | 2. Fan venturi, P/N 132322-2-1, may not be installed on any aeroplane as a replacement part unless the fan venturi has been modified in accordance with Requirement 1.a. or unless the fan venturi has a new P/N in accordance with Requirement 1.b.                                    |\n|                | Later revisions of the above Raytheon SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2006-01-04, are considered acceptable for compliance with the equivalent Requirements of this Directive.            |\n|                | Note 2: FAA AD 2006-01-04 Amdt 39-14443 refers.                                                                                                                                                                                                                                         |\n| Compliance:    | For Requirement 1 - Within 1,200 hours time in service or 24 months after the effective date of this Directive, whichever occurs first.                                                                                                                                                 |\n|                | For Requirement 2 - As of the effective date of this Directive.                                                                                                                                                                                                                         |\n|                | This Airworthiness Directive becomes effective on 11 May 2006.                                                                                                                                                                                                                          |\n\n| Background: | This Directive supersedes AD/HS 125/141 which applied to Raytheon aeroplanes identified above. That Directive required a visual inspection to determine whether adequate clearance exists between the fan venturi motor casing and the adjacent equipment together with any necessary adjustments. The Directive also required a visual inspection to detect signs of overheating, degradation of insulating materials, and ingestion of debris into the motor together with the replacement of discrepant parts with serviceable parts. |\n| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | This new Directive instead requires that operators replace the fan venturi with a new or modified part. This results from advice from the United States Federal Aviation Administration that the fan venturi overheated and produced smoke while the aeroplane was on the ground. This Directive is issued to prevent heat and fire damage to equipment adjacent to the fan venturi, which could result in smoke in the cabin and/or burning equipment.                                                                                  |\n\n![](image.001.png)  \nJames Coyne  \nDelegate of the Civil Aviation Safety Authority\n\n28 March 2006","sortOrder":0},{"sectionNumber":"AD/HS 125/178","sectionType":"part","heading":"AD/HS 125/178","content":"## AD/HS 125/178","sortOrder":1},{"sectionNumber":"Air Conditioning - Fan Venturi Motor","sectionType":"part","heading":"Air Conditioning - Fan Venturi Motor","content":"## Air Conditioning - Fan Venturi Motor","sortOrder":2},{"sectionNumber":"5/2006","sectionType":"part","heading":"5/2006","content":"## 5/2006","sortOrder":3}],"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"},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"Yes. The Directive replaces a prior inspection-and-adjustment requirement with a mandatory modification or replacement of the fan venturi to eliminate overheating risk, moving from a monitoring/repair approach to compulsory part change (Background; Requirement 1 & Requirement 2)."},"complexity_factors":["Specific part-number mandates and prohibitions (P/N 132322-2-1, 132322-3-1, 207640-34) create tight technical constraints (Requirement 1; Requirement 2).","Applicability spans multiple Raytheon/BAe/Hawker model variants identified by Raytheon Service Bulletin SB 21-3669, requiring operators to check aircraft applicability (Applicability).","Cross-references to manufacturer service bulletins (Raytheon SB 21-3669 and Honeywell SB 132322-21-4041) increase procedural complexity for maintenance planning (Note 1).","Compliance deadline of 1,200 flight hours or 24 months imposes a fixed scheduling window for operators (Compliance).","Supersedes an inspection-based directive and replaces it with mandatory modification or replacement, changing maintenance strategy and likely costs (Background; Requirement 1).","Prohibition on installing the unmodified venturi as a replacement creates spare-part and logistics constraints for maintenance organisations (Requirement 2).","Limited administrative flexibility: later revisions of the Raytheon SB approved by the FAA as an AMOC are acceptable, which provides a single channel for alternative compliance but relies on FAA approval (\"Later revisions...FAA AMOC\").","Who bears cost and performs work is clear (operators must carry out the modification or replacement), concentrating immediate costs on aircraft owners/operators (Requirement 1; Compliance)."],"plain_english_summary":"Requires operators of specified Raytheon/BAe 125 and Hawker 800/1000 series aeroplanes to either fit an improved fan venturi motor (P/N 207640-34) or replace the venturi with P/N 132322-3-1, and bans installing the older P/N 132322-2-1 unless modified. Compliance must occur within 1,200 flight hours or 24 months. The directive's stated purpose is to prevent fan venturi overheating, smoke or fire damage to adjacent equipment (Requirement 1; Requirement 2; Background)."},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"This directive maintains its original narrow scope — addressing a specific air conditioning component failure risk in a defined aircraft fleet. It replaces an earlier directive on the same subject but does not expand beyond the original safety purpose of preventing fan venturi overheating."},"complexity_factors":["Single, specific mechanical component targeted (fan venturi motor)","Only two compliance options provided (modify or replace)","Clear applicability criteria tied to specific aircraft models and service bulletin","Straightforward timeline with binary trigger (hours OR months)","Limited cross-referencing: only references one superseded directive (AD/HS 125/141), one Raytheon service bulletin, and one FAA AD","No nested exceptions or conditional logic beyond the two alternative compliance methods","Short document length with minimal defined terms"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of certain BAe/Raytheon Hawker 800/1000 series jets (those listed in Raytheon SB 21-3669) to fix a defective fan venturi motor that can overheat, smoke, and potentially cause fire. \n\nOperators must either install the improved motor (P/N 207640-34) or replace the venturi with the redesigned unit (P/N 132322-3-1); modifications are due within 1,200 flight hours or 24 months after 11 May 2006, and use of the old unmodified part is prohibited from that date."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-178-air-conditioning-fan-venturi-motor","history":"/api/acts/ad-hs-125-178-air-conditioning-fan-venturi-motor/history","analysis":"/api/acts/ad-hs-125-178-air-conditioning-fan-venturi-motor/analysis","conflicts":"/api/acts/ad-hs-125-178-air-conditioning-fan-venturi-motor/conflicts","importantCases":"/api/acts/ad-hs-125-178-air-conditioning-fan-venturi-motor/important-cases","documents":"/api/acts/ad-hs-125-178-air-conditioning-fan-venturi-motor/documents"}}