{"id":"F2006B10042","name":"AD/G1159/39 - Landing Gear Door Control Valves","slug":"ad-g1159-39-landing-gear-door-control-valves","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55463,"registerId":"commonwealth-F2006B10042-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"AIRWORTHINESS DIRECTIVE","sectionType":"part","heading":"AIRWORTHINESS DIRECTIVE","content":"# AIRWORTHINESS DIRECTIVE\n\n![](image.002.png)\n\n![](image.002.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.","sortOrder":0},{"sectionNumber":"AD/G1159/39 Landing Gear Door Control Va","sectionType":"part","heading":"AD/G1159/39 Landing Gear Door Control Valves 7/2001","content":"# AD/G1159/39 Landing Gear Door Control Valves 7/2001\n\nDM\n\nApplicability: Gulfstream Model G-1159, G-1159A, G-1159B, G-IV, and G-V series aeroplanes.\n\nRequirement: 1. Perform a visual inspection to determine if any landing gear door control valve having Gulfstream part number (P/N) 1159SCH231-33 with Eaton/Sterer P/N 65940-1, -1 Rev. A, or -1 Rev. B, is installed.\n\nNo further action is required if there are no P/N 1159SCH231-33 with Eaton/Sterer P/N 65940-1, -1 Rev. A, or -1 Rev. B valves installed on the aircraft.\n\n    2. If during the inspection, any landing gear door control valve having P/N 1159SCH231-33 with Eaton/Sterer P/N 65940-1, \\-1 Rev. A, or \\-1 Rev. B is found:\n\nReplace the set screw with a new set screw, fill with Dow Corning RTV 732 sealant, and label the valve as P/N 65490-1 Rev. C; in accordance with; Gulfstream G-II Alert Customer Bulletin (ACB) No. 27 (for Model G-1159 and G- 1159A series aeroplanes); G-III ACB No. 13 (for model G-1159B series aeroplanes); G-IV ACB No. 27 (for Model G-IV series aeroplanes); and G-V ACB No.12 (for Model G-V series aeroplane); all dated 20 March 2001, as applicable.\n\n    3. Do not install a landing gear door control valve unless it\n\n    (a) has been modified according to Requirement 2 or\n\n    (b) is of P/N 1159CH231-33 with Eaton/Sterer P/N 65940-1, Rev. C.\n\nNote: FAA AD 2001-08-13 refers.","sortOrder":1}],"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"},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original, narrow scope: addressing a specific unsafe condition in a particular valve component on specific Gulfstream aircraft. It has not expanded beyond this original safety purpose."},"complexity_factors":["Single, specific technical issue (one valve part number)","Clear binary decision tree: inspect → if found, modify → if not found, no action","Only 3 requirements with straightforward conditional logic","Minimal cross-referencing (references specific Gulfstream service bulletins by number and date, plus FAA AD for context)","No nested exceptions or complex definitions section","Narrow applicability (5 specific aircraft model series)"],"plain_english_summary":"Owners/operators of certain Gulfstream G‑II through G‑V business jets must inspect landing‑gear door control valves for a specific vulnerable part number. If found, the AD mandates replacing a set screw, applying sealant and relabeling the valve to the safer revision; unmodified valves may not be installed going forward. This required action prevents valve failure that could stop gear from deploying, addressing a serious landing‑safety risk."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD maintains a focused scope: it applies only to listed Gulfstream models and to landing-gear-door control valves with the specified Gulfstream and Eaton/Sterer part numbers (Applicability; Requirement 1). The directive prescribes inspection, a defined modification, relabelling, and an installation ban unless the valve meets the revised P/N or has been modified (Requirements 2–3); it does not broaden coverage beyond those parts or models."},"complexity_factors":["Narrow technical scope: targets a specific component (landing gear door control valve) and precise part numbers (Applicability; Requirement 1).","Cross-referencing: mandates modification in accordance with external Gulfstream Alert Customer Bulletins dated 20 March 2001 (Requirement 2), requiring operators to obtain and follow those documents.","Modification detail: requires a specific hardware change (replace set screw), application of a specific sealant (Dow Corning RTV 732), and relabelling to a new P/N (Requirement 2).","Installation restriction: prohibits installing valves unless modified or already at the revised Eaton/Sterer P/N Rev. C (Requirement 3), creating an on‑going procurement constraint for maintenance organisations.","Regulatory linkage: notes the related FAA AD (Note), creating a need to check parallel foreign-airworthiness guidance.","Operational burden: imposes inspection and one-time modification costs on aircraft operators and maintenance providers and implies record-keeping and parts-control actions (Requirements 1–3)."],"plain_english_summary":"This Airworthiness Directive requires operators of Gulfstream G-1159, G-1159A/B, G‑IV and G‑V series aeroplanes to inspect for landing-gear-door control valves with specified Gulfstream and Eaton/Sterer part numbers and, if found, replace the set screw, apply Dow Corning RTV 732 sealant and relabel the valve per Gulfstream Alert Customer Bulletins (Requirement 1–2). It also prohibits installing affected valves unless they are modified as required or already carry the revised part number (Requirement 3). Operators pay for inspection and modification and must ensure future installs meet the AD."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g1159-39-landing-gear-door-control-valves","history":"/api/acts/ad-g1159-39-landing-gear-door-control-valves/history","analysis":"/api/acts/ad-g1159-39-landing-gear-door-control-valves/analysis","conflicts":"/api/acts/ad-g1159-39-landing-gear-door-control-valves/conflicts","importantCases":"/api/acts/ad-g1159-39-landing-gear-door-control-valves/important-cases","documents":"/api/acts/ad-g1159-39-landing-gear-door-control-valves/documents"}}