{"id":"F2006B10448","name":"AD/HS 125/166 Amdt 2 - Main Landing Gear Actuator Cylinder Head","slug":"ad-hs-125-166-amdt-2-main-landing-gear-actuator-cylinder-head","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116159,"registerId":"commonwealth-F2006B10448-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 125/166 Amdt 2 - Main Landing Gear Actuator Cylinder Head","content":"![](image.001.png)\n\n![](image.001.png)  \nAIRWORTHINESS DIRECTIVE\n\nFor the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/HS 125/166 Amdt 1 and issues the following 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.001.png)\n\nBritish Aerospace BAe 125 Series Aeroplanes\n\nAD/HS 125/166\n\nAmdt 2\n\n  \nMain Landing Gear Actuator Cylinder Head 5/2003\n\nApplicability: Model DH.125, HS.125 and BH.125 series aircraft; and Model BAe. 125 series 800A, 800B, 1000A, and 1000B aircraft; and Model Hawker 800, 1000, and 800XP aircraft; as listed in Raytheon Service Bulletin 32-3391, dated August 2000.\n\nRequirement: Inspect in accordance with Raytheon Service Bulletin 32-3391.\n\nNote: FAA AD 2003-04-20 Amdt 39-13069 refers.\n\nCompliance: 1. For actuator cylinder heads that have been in service for more than 7 years or that have 4,001 or more total landings as at 15 May 2003, perform the eddy current inspection within 6 Months or 10 landings after 15 May 2003, whichever occurs first, unless already accomplished.\n\n2. For all other actuator cylinder heads, as specified in the Requirement document. This amendment becomes effective on 16 May 2002.\n\nBackground: The FAA received reports of attachment lugs cracking at the main landing gear actuator cylinder head, with two incidents leading to actuator separation, which resulted in airframe damage.\n\nAmendment 1 corrected and clarified certain affected aircraft serial numbers.\n\nAmendment 2 is issued in response to a new FAA AD, which expands and clarifies applicability, and additionally, clarifies inspection compliance time.\n\nAme ndment 1 of this Airworthiness Directive became effective on 16 May 2002.\n\nBritish Aerospace BAe 125 Series Aeroplanes\n\nAD/HS 125/166 Amdt 2 (continued)\n\nThe original issue of this Airworthiness Directive became effective on 7 November 2001.\n\n![](image.002.jpeg)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 3 April 2002\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 23 April 2003.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"Amendment 2 expands and clarifies the AD's applicability and inspection compliance times relative to the prior amendment. It revokes AD/HS 125/166 Amdt 1 and adopts the expanded applicability and revised timing introduced in the referenced FAA AD, changing which serials/aircraft and which service‑life thresholds trigger earlier inspection."},"complexity_factors":["Targeted hardware: applies to a specific component (main landing‑gear actuator cylinder head) rather than entire aircraft systems, which narrows but technicalises compliance.","Multiple model applicability: covers several BAe 125 / Hawker model series as listed in an external Raytheon Service Bulletin, requiring operators to cross‑check serials against that bulletin.","External document dependency: mandates inspection 'in accordance with Raytheon Service Bulletin 32‑3391', creating reliance on an external maintenance document for procedures and thresholds.","Tiered compliance timings: faster deadlines for parts >7 years old or ≥4,001 landings (inspection within 6 months or 10 landings after 15 May 2003), and different timing for other heads per the Requirement document.","Inspection method specificity: requires an eddy‑current inspection (a specialist non‑destructive test), which imposes qualification and equipment demands on maintenance providers.","Regulatory layering: references and aligns with FAA AD 2003‑04‑20 and revokes a prior Australian amendment, adding procedural traceability for international coordination.","Date references: effective and compliance dates in the text (original AD 7 Nov 2001; Amendment 1 effective 16 May 2002; compliance benchmark 15 May 2003) may create administrative tracking complexity for operators.","Implementation cost: inspection and any subsequent repair/replacement costs fall on aircraft operators; frequency and urgency for older/heavily used parts concentrates near‑term burden on a subset of operators."],"plain_english_summary":"Requires eddy‑current inspection of the main landing‑gear actuator cylinder head on the listed BAe 125 / Hawker models, to be done following Raytheon Service Bulletin 32‑3391. Operators of those aircraft must inspect sooner for heads older than 7 years or with 4,001+ total landings as measured at 15 May 2003. The directive responds to reports of attachment‑lug cracking and two actuator separations that caused airframe damage."},"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"},"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":true,"description":"The original directive (November 2001) addressed a specific unsafe condition. Amendment 1 (May 2002) corrected aircraft serial numbers. Amendment 2 (April 2003) significantly expanded applicability to cover additional aircraft models (Hawker 800XP and clarified series designations) and introduced a two-tier compliance schedule based on aircraft age/usage, moving beyond the original 'one-size-fits-all' approach. The scope evolved from a basic inspection mandate to a more nuanced, risk-based compliance framework."},"complexity_factors":["Short, single-purpose directive (approximately 400 words)","Only 4 defined applicability categories (aircraft model series)","Two-tier compliance structure (high-time vs. other aircraft)","Single cross-reference to external technical document (Raytheon Service Bulletin 32-3391)","References to FAA AD for background context but doesn't incorporate by complex conditional logic","Clear, sequential structure: Applicability → Requirement → Compliance → Background","No nested exceptions or conditional definitions"],"plain_english_summary":"This AD mandates mandatory inspections of main landing gear actuator cylinder heads on certain BAe 125/Hawker 800/1000 series aircraft after reports of cracked attachment lugs and two separations. Owners/operators must inspect high‑risk aircraft quickly (per the AD) and follow the referenced service bulletin for others. Amendment 2 expands affected aircraft and clarifies required inspection timing."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-166-amdt-2-main-landing-gear-actuator-cylinder-head","history":"/api/acts/ad-hs-125-166-amdt-2-main-landing-gear-actuator-cylinder-head/history","analysis":"/api/acts/ad-hs-125-166-amdt-2-main-landing-gear-actuator-cylinder-head/analysis","conflicts":"/api/acts/ad-hs-125-166-amdt-2-main-landing-gear-actuator-cylinder-head/conflicts","importantCases":"/api/acts/ad-hs-125-166-amdt-2-main-landing-gear-actuator-cylinder-head/important-cases","documents":"/api/acts/ad-hs-125-166-amdt-2-main-landing-gear-actuator-cylinder-head/documents"}}