{"id":"F2006B10450","name":"AD/HS 125/168 - Engine Overspeed Control","slug":"ad-hs-125-168-engine-overspeed-control","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116163,"registerId":"commonwealth-F2006B10450-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.001.png)\n\n![](image.001.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.\n\nBritish Aerospace BAe 125 Series Aeroplanes","sortOrder":0},{"sectionNumber":"AD/HS 125/168 Engine Overspeed Control 3","sectionType":"part","heading":"AD/HS 125/168 Engine Overspeed Control 3/2003","content":"# AD/HS 125/168 Engine Overspeed Control 3/2003\n\nApplicability: Model Hawker 800XP aeroplanes, as listed in Raytheon Service Bulletin SB 76-3480 dated August 2001.\n\nRequirement: Carry out the following actions in accordance with SB 76-3480:\n\n    Install a four-inch jumper wire between terminals 1 and 3 on the computer control switch \"NF\".\n\n    2. Install a six-inch jumper wire between terminals 1 and 3 on the computer control switch \"NG\".\n\n    3. Tie and stow the jumper wires on the computer control switches \"NF\" and \"NG\" using tie-wrap.\n\nNote: FAA AD 2002-26-22 Amdt 39-13011 refers.\n\nCompliance: Within 3 months or 300 hours time in service after the effective date of this Directive, whichever occurs first.\n\nThis Airworthiness Directive becomes effective on 20 March 2003.\n\nBackground: This Directive requires the installation of jumper wires on the computer control switches to power the digital electronic engine control when overspeed protection is selected, together with the tying and stowing of the jumper wires on the switches.\n\nThese actions are intended to prevent loss of the overspeed protection function without the flight crew's awareness, which could result in engine overspeed and possible uncommanded engine shutdown.\n\n![](image.002.png)  \n\nJames Coyne\n\nDelegate of the Civil Aviation Safety Authority 28 January 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 26 February 2003.","sortOrder":1}],"analysis":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The Directive's scope matches the stated objective in the Background: it mandates specific wiring changes on listed Hawker 800XP aircraft to preserve overspeed protection. There is no text indicating an expansion or narrowing of scope beyond the Applicability and the specific Requirement."},"complexity_factors":["Narrow applicability: applies only to Hawker 800XP models listed in Raytheon SB 76-3480 (Applicability).","Simple, specific hardware change: install jumper wires between terminals 1 and 3 on NF and NG computer control switches and tie/stow them (Requirement).","Dependence on an external service bulletin for implementation details (Requirement references SB 76-3480).","Short compliance window creates operational scheduling pressure: within 3 months or 300 hours time in service (Compliance).","Safety-critical objective stated: maintain power to digital electronic engine control when overspeed protection is selected to avoid engine overspeed or uncommanded shutdown (Background).","Regulatory authority and enforceability: issued by CASA under CAR 1998 subregulation 39.1(1) (preamble), so aircraft operators/owners are required to carry out the work (Requirement & Compliance).","Low technical complexity but requires access to control switches and minor wiring work — cost and labour borne by the operator (inferred from Requirement and Compliance).","Cross-reference to FAA AD 2002-26-22 (Note) indicates harmonisation with foreign airworthiness directive frameworks."],"plain_english_summary":"Sets a mandatory maintenance requirement for Hawker 800XP aeroplanes: install two jumper wires between terminals 1 and 3 on the NF and NG computer control switches and secure them, following Raytheon Service Bulletin SB 76-3480. The Directive says this will keep the digital electronic engine control powered when overspeed protection is selected, preventing unnoticed loss of overspeed protection; operators must comply within 3 months or 300 flight hours."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow Airworthiness Directive addressing a specific unsafe condition in a specific aircraft model. The scope remains tightly focused on the original safety issue — preventing loss of engine overspeed protection — with no expansion beyond the technical fix required."},"complexity_factors":["Single, discrete technical requirement with only 3 specific actions","No defined terms section — all terminology is standard aviation maintenance language","Minimal conditional logic: only one applicability criterion (specific aircraft model)","Simple compliance trigger: time-based OR flight hours-based deadline","No cross-references to other legislation beyond a single reference to an FAA equivalent directive","Short document (approximately 250 words of substantive text)"],"plain_english_summary":"This mandatory CASA Airworthiness Directive requires owners/operators of Hawker 800XP jets to have maintenance install two jumper wires on the engine computer control switches (NF and NG) to ensure the digital engine control remains powered when overspeed protection activates. Compliance is required within 3 months or 300 flight hours of 20 March 2003.\n\nThe fix prevents a silent failure of the overspeed protection that could allow an engine to overspeed and shut down in flight, posing a serious safety risk."},"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"}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-125-168-engine-overspeed-control","history":"/api/acts/ad-hs-125-168-engine-overspeed-control/history","analysis":"/api/acts/ad-hs-125-168-engine-overspeed-control/analysis","conflicts":"/api/acts/ad-hs-125-168-engine-overspeed-control/conflicts","importantCases":"/api/acts/ad-hs-125-168-engine-overspeed-control/important-cases","documents":"/api/acts/ad-hs-125-168-engine-overspeed-control/documents"}}