{"id":"F2009L04657","name":"AD/G1159/35 Amdt 1 - Takeoff Warning System","slug":"ad-g1159-35-amdt-1-takeoff-warning-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":82551,"registerId":"commonwealth-F2009L04657-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Gulfstream (Grumman) G1159 and G-IV Seri","sectionType":"division","heading":"Gulfstream (Grumman) G1159 and G-IV Series Aeroplanes","content":"### Gulfstream (Grumman) G1159 and G-IV Series Aeroplanes\n\n| AD/G1159/35 Amdt 1 | Takeoff Warning System | 25/2009 |\n| ------------------ | ---------------------- | ------- |\n\n| Applicability: | All Model G-II (G-1159), G-III (G-1159A), G-IIB (G-1159B) series aeroplanes and G-IV series aeroplanes serial numbers 1000 through 1092.                                                                                                                                       |\n| -------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |\n| Requirement:   | 1. For applicable aircraft carry out the following:                                                                                                                                                                                                                            |\n|                | a. For all Model G-II (G-1159) and G-IIB (G-1159B) series aeroplanes - Perform an operational check of the takeoff warning system in accordance with Gulfstream Aerospace Customer Bulletin (CB) Number 388, Amendment 1, dated 15 August 1989.                                |\n|                | b. For all Model G-III (G-1159A) series aeroplanes - Perform an operational check of the takeoff warning system, in accordance with Gulfstream CB Number 106, dated 1 May 1989.                                                                                                |\n|                | c. For Model G-IV series aeroplanes, - Perform an operational check in accordance with Gulfstream Aircraft Service Change (ASC) Number 122, dated 31May 1989.                                                                                                                  |\n|                | 2. Repair non functioning systems found during the Requirement 1 operational check in accordance with the CB or ASC as applicable.                                                                                                                                             |\n|                | 3. For Model G-IV series aeroplanes, if not previously accomplished, modify the takeoff warning range indication system in accordance Gulfstream ASC Number 122.                                                                                                               |\n|                | Later revision(s) of the above CB(s) or ASC approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 90-02-05 is/are considered acceptable for compliance with the equivalent Requirements of this Amendment. |\n|                | Note: FAA AD 90-02-05 Amdt 39-6472 refers.                                                                                                                                                                                                                                     |\n| Compliance:    | For Requirement 1 -If repetitive checks have been or are being accomplished in accordance with either AD/G1159/35 or FAA AD 90-02-05 Amdt 39-6472 continue the checks at intervals not to exceed 150 hours time-in-service (TIS).                                              |\n\n|             | b. If repetitive checks have not, or are not, being accomplished in accordance with AD/G1159/35 or FAA AD 90-02-05 Amdt 39-6472 perform an initial check within 25 hours TIS after the effective date of this Amendment and thereafter at intervals not to exceed 150 hours TIS.                                                                                                                                                                                                                                                                                                                                                                                                                            |\n| ----------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|             | For Requirement 2 - After the Requirement 1 operational check.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |\n|             | For Requirement 3 - Within 25 hours TIS after the effective date of this Directive.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |\n|             | This Amendment becomes effective on 22 December 2009.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |\n| Background: | Operator reports involving the following discrepancies, elongated bolt holes, cracks and loose fasteners in the rudder actuator attachment area, have been received by the manufacturer.The original issue of this Directive only applied to GII and GIIB series aeroplanes and required initial and repetitive operational checks of the takeoff warning system.This amendment continues the repetitive operational checks and extends the applicability of the Directive to include G-III aeroplanes and certain G-IV aeroplanes; it also requires a modification of the takeoff warning range indication system forG-IV aeroplanes.The original issue of this Directive became effective on 17 May 1990. |\n\n![](image.001.png)\n\nWilliam David  \nDelegate of the Civil Aviation Safety Authority\n\n11 December 2009","sortOrder":0},{"sectionNumber":"AD/G1159/35 Amdt 1","sectionType":"part","heading":"AD/G1159/35 Amdt 1","content":"## AD/G1159/35 Amdt 1","sortOrder":1},{"sectionNumber":"Takeoff Warning System","sectionType":"part","heading":"Takeoff Warning System","content":"## Takeoff Warning System","sortOrder":2},{"sectionNumber":"25/2009","sectionType":"part","heading":"25/2009","content":"## 25/2009","sortOrder":3}],"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":3,"scope_assessment":{"changed":true,"description":"The original 1990 directive only covered G-II and G-IIB aircraft. This 2009 amendment significantly expanded scope to include G-III aircraft and G-IV aircraft (serial numbers 1000-1092), and added a new modification requirement for G-IV aircraft that wasn't in the original."},"complexity_factors":["Multiple aircraft models with slightly different compliance paths (G-II/G-IIB vs G-III vs G-IV)","Cross-references to external manufacturer documents (Gulfstream Customer Bulletins and Aircraft Service Changes) rather than spelling out procedures in the text","Conditional compliance based on prior inspection history (whether operators were already doing repetitive checks)","Reference to US FAA Airworthiness Directive as an acceptable alternative compliance method","Nested applicability criteria (serial number range for G-IV only)"],"plain_english_summary":"This CASA Airworthiness Directive requires owners/operators of certain Gulfstream G‑II/G‑III/G‑IIB and early G‑IV (S/N 1000–1092) jets to perform recurrent operational checks of the takeoff warning system, repair any failures, and install a G‑IV modification. It addresses mechanical issues in the rudder actuator area that could disable a critical takeoff‑configuration alert."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":true,"description":"This amendment expands the original Directive's scope. The original Directive applied only to G‑II and G‑IIB series aeroplanes and required initial and repetitive operational checks. This amendment extends applicability to include G‑III aeroplanes and certain G‑IV aeroplanes (serial numbers 1000–1092) and adds a mandatory modification of the takeoff warning range indication system for G‑IV aeroplanes that have not already been modified (see Background and Requirements 1–3)."},"complexity_factors":["Single airworthiness directive amendment with limited text but multiple cross‑references","References three separate manufacturer service documents (Gulfstream CB No. 388 Amendment 1; CB No. 106; ASC No. 122)","Accepts later revisions approved by the FAA as Alternate Methods of Compliance (AMOC) — introduces cross‑jurisdictional compliance dependency","Contains model and serial‑number specificity (all G‑II, G‑IIB, G‑III; G‑IV serial numbers 1000–1092)","Two compliance timing paths (operators already performing checks vs operators not performing checks) with different effective start times","Separate repair obligation and an additional hardware modification requirement for G‑IVs","Short, concrete deadlines (25 hours TIS for initial checks or G‑IV modification; 150 hours TIS recurring interval)","Background material referencing prior issue and expansion of applicability (useful for scope but not operational complexity)"],"plain_english_summary":"**What this Directive does (mechanically)\n\n- Requires operators of specified Gulfstream G‑II (G‑1159), G‑IIB (G‑1159B), G‑III (G‑1159A) and certain G‑IV series aeroplanes (serial numbers 1000–1092) to carry out operational checks of the takeoff warning system and to repair any faults found (Requirement 1 and 2).\n- Sets which manufacturer documents must be used to perform the checks: Gulfstream Customer Bulletin (CB) No. 388 Amendment 1 for G‑II and G‑IIB; CB No. 106 for G‑III; and Aircraft Service Change (ASC) No. 122 for G‑IV (Requirement 1(a)–(c)).\n- For G‑IV aeroplanes, additionally requires a modification of the takeoff warning range‑indication system if that modification has not already been done (Requirement 3).\n- Allows later revisions of the specified CB(s) or ASC approved by the U.S. Federal Aviation Administration as an Alternate Method of Compliance to be used instead (AMOC provision).\n- Prescribes compliance timing: either continue existing repetitive checks at intervals not exceeding 150 hours time‑in‑service (TIS) if they are already being done under the prior AD; or, if not already being done, perform an initial check within 25 hours TIS of this amendment and then at intervals not exceeding 150 hours TIS (Compliance section). Repairs must be done after the operational check; the G‑IV modification must be done within 25 hours TIS if not previously accomplished.\n\nWho it affects\n\n- Aircraft owners and operators of the listed Gulfstream models and serial‑numbered G‑IVs (they pay for and arrange the inspections, repairs and any required modification).\n- Maintenance organisations and certificated mechanics who perform the operational checks, repairs and modification (they carry out the work to the specified Gulfstream CB/ASC).\n- The regulator (Civil Aviation Safety Authority, via the Deputy/Delegate named) enforces the requirement and accepts FAA‑approved AMOCs.\n\nWhy it matters (stated purpose and practical effect)\n\n- Stated purpose: respond to reported discrepancies around the rudder actuator attachment area and ensure the takeoff warning system functions correctly to reduce the risk of takeoff configuration hazards (Background). The Directive requires routine operational checks, fixes for non‑functioning systems, and a hardware modification for certain G‑IV aeroplanes.\n\nPractical impacts, trade‑offs and implementation considerations\n\n- Who pays and who decides: aircraft operators pay for inspections, repairs and modifications; maintenance providers undertake the work; the regulator enforces compliance and may accept FAA‑approved alternative methods.\n- Costs and opportunity cost: labour time, possible parts, and aircraft downtime for checks, repairs and the G‑IV modification. These are recurring costs while the repetitive inspection regime remains in force (150‑hour interval).\n- Incentives and behaviour change: operators are incentivised to keep the takeoff warning system operational and to perform the mandated modification on affected G‑IV airframes; some operators may choose to preemptively modify equipment to avoid repeated operational checks.\n- Compliance burden and implementation risk: reliance on manufacturer CBs/ASC and FAA AMOCs means operators must have access to the correct service documents and acceptable AMOCs; scheduling repetitive checks into flight operations is an administrative burden. Availability of approved parts or approved modification procedures could affect time to compliance.\n- Effects on private markets: creates predictable demand for maintenance labour and parts for the affected models; may increase short‑term maintenance expenses and scheduling constraints for operators, but channels work to certificated maintenance organisations.\n\nRelevant cross‑references in the Directive\n\n- The Directive references FAA AD 90‑02‑05 Amdt 39‑6472 and accepts FAA‑approved later revisions of the stated CB(s)/ASC as acceptable AMOCs.\n\nWhich behaviours are required and when (concise)\n\n- If you already perform the required repetitive takeoff warning checks under the prior AD, continue them at intervals not exceeding 150 hours TIS.\n- If you are not performing them, do an initial operational check within 25 hours TIS of this amendment date and then repeat at intervals not exceeding 150 hours TIS (Requirement 1 and Compliance).\n- Repair any non‑functioning system found during the check (Requirement 2).\n- For affected G‑IV aeroplanes not already modified, complete the takeoff warning range indication modification within 25 hours TIS (Requirement 3)."}},"importantCases":[],"_links":{"self":"/api/acts/ad-g1159-35-amdt-1-takeoff-warning-system","history":"/api/acts/ad-g1159-35-amdt-1-takeoff-warning-system/history","analysis":"/api/acts/ad-g1159-35-amdt-1-takeoff-warning-system/analysis","conflicts":"/api/acts/ad-g1159-35-amdt-1-takeoff-warning-system/conflicts","importantCases":"/api/acts/ad-g1159-35-amdt-1-takeoff-warning-system/important-cases","documents":"/api/acts/ad-g1159-35-amdt-1-takeoff-warning-system/documents"}}