{"id":"F2006B10560","name":"AD/HS 748/25 Amdt 1 - Control System Gust Locks","slug":"ad-hs-748-25-amdt-1-control-system-gust-locks","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":116383,"registerId":"commonwealth-F2006B10560-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/HS 748/25 Amdt 1 - Control System Gust Locks","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 748/25 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 (Hawker Siddeley) HS 748 Series Aeroplanes\n\nAD/HS 748/25\n\nAmdt 1\n\n  \nControl System Gust Locks 3/2003\n\nApplicability: All Series HS 748 aircraft.\n\nRequirement: Action in accordance with BAE Systems Mandatory Service Bulletin HS748-A27- 128 Revision 1.\n\nNote: UK CAA AD 008-12-96 refers.\n\nCompliance: For Part 1 of the Requirement document:\n\nAt the next scheduled Check C inspection after 20 March 2003. Repeat thereafter at each Check C inspection.\n\nFor Part 2 of the Requirement document:\n\nWithin 750 flight hours after accomplishment of the initial Part 1 inspection. Repeat thereafter at each Period 1 inspection.\n\nThis Amendment becomes effective on 20 March 2003.\n\nBackground: Following a flight control restriction incident, investigation revealed deficiencies in the rigging of the gust lock system. This Directive introduces new inspection, rectification, and rigging actions, and highlights correct control system maintenance practices.\n\nBritish Aerospace (Hawker Siddeley) HS 748 Series Aeroplanes\n\nAD/HS 748/25 Amdt 1 (Continued)\n\nAmendment 1 is issued in response to a revision of the Requirement document, which introduces new instructions applicable to aircraft that have Modification 7673 (SB HS748-27-135) incorporated.\n\nThe original issue of this Airworthiness Directive became effective on 23 April 1998.\n\n![Signature of David Villiers](image.002.png)  \n\nDavid Alan Villiers\n\nDelegate of the Civil Aviation Safety Authority 30 January 2003\n\n![](image.001.png)  \n\nThe above AD is notified in the Commonwealth of Australia Gazette on 26 February 2003.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":3,"scope_assessment":{"changed":false,"description":"The amendment stays within the original scope of addressing gust lock system safety. It simply expands the instructions to cover aircraft with a specific modification (Mod 7673), which is a natural evolution of the original safety mandate rather than scope creep."},"complexity_factors":["Short, single-purpose document (2 pages)","Only 1 defined term implicitly referenced (Check C/Period 1 inspections are industry standard terms, not defined here)","Simple conditional structure: two-part requirement with different compliance timelines","Cross-reference to external technical document (BAE Systems Service Bulletin) without reproducing its contents","Single amendment tracking (original 1998 issue, amended 2003)","No nested exceptions or complex definitional sections"],"plain_english_summary":"This AD from CASA applies to British Aerospace HS 748 aircraft and mandates inspection and corrective action on the gust lock system after a flight-control restriction incident revealed incorrect rigging that could impair control. Owners must inspect at the next Check C after 20 Mar 2003 and at each subsequent Check C, with additional work within 750 flight hours of that inspection and repeating at each Period 1.\n\nAmendment 1 adds specific instructions for aircraft fitted with Modification 7673."},"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":true,"description":"Amendment 1 revises the Requirement document to add specific instructions for aircraft with Modification 7673 (SB HS748‑27‑135). Applicability remains all HS 748 series, but the technical actions required were broadened to address aircraft incorporating that modification; the AD thus changed the required maintenance instructions rather than the population covered."},"complexity_factors":["Cross‑reference to an external mandatory service bulletin (HS748‑A27‑128 Rev 1) — compliance depends on following another document (Requirement).","Two different inspection schedules with different triggers (next scheduled Check C after 20 Mar 2003 and within 750 flight hours after initial Part 1) and repeat obligations (Compliance).","Applicability to all HS 748 series aircraft simplifies scope but requires fleet‑wide compliance (Applicability).","Amendment introduces additional instructions for aircraft with Modification 7673 (SB HS748‑27‑135), adding conditional technical complexity (Background/Amendment note).","Regulatory mechanism: revokes prior AD and is issued under CAR 1998 subregulation 39.1(1), so enforcement and legal effect rest with CASA delegate (preamble/signature).","Operational burden: recurring inspections and potential rectification impose scheduling and maintenance costs on operators (Compliance/Requirement)."],"plain_english_summary":"This AD requires all British Aerospace (Hawker Siddeley) HS 748 series aircraft to follow BAE Systems Mandatory Service Bulletin HS748‑A27‑128 Revision 1 to inspect, rig and, if necessary, rectify the gust‑lock/control system. It revokes the earlier AD and sets mandatory inspection intervals tied to Check C and Period 1 with repeat requirements. Operators pay for inspections and repairs. The CASA delegate issues and enforces the directive, which changes maintenance scheduling and rigging practice for affected aircraft."}},"importantCases":[],"_links":{"self":"/api/acts/ad-hs-748-25-amdt-1-control-system-gust-locks","history":"/api/acts/ad-hs-748-25-amdt-1-control-system-gust-locks/history","analysis":"/api/acts/ad-hs-748-25-amdt-1-control-system-gust-locks/analysis","conflicts":"/api/acts/ad-hs-748-25-amdt-1-control-system-gust-locks/conflicts","importantCases":"/api/acts/ad-hs-748-25-amdt-1-control-system-gust-locks/important-cases","documents":"/api/acts/ad-hs-748-25-amdt-1-control-system-gust-locks/documents"}}