{"id":"F2006B10774","name":"AD/IAI-A/17 - Main Landing Gear Ground Contact Switches","slug":"ad-iai-a-17-main-landing-gear-ground-contact-switches","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56227,"registerId":"commonwealth-F2006B10774-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/IAI-A/17 - Main Landing Gear Ground Contact Switches","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  \n\n\n# AIRWORTHINESS DIRECTIVE\n\n![](image.001.png)  \n\n\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 CASR 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\n\n \n\nIsrael Aircraft Industries 1125 (Astra) Series Aeroplanes\n\n \n\n# AD/IAI-A/17 Main Landing Gear Ground Contact Switches\n\n\n12/2003\n\n \n\n \n\nApplicability: Gulfstream Aerospace LP (GALP) Model 1125 Astra, Astra SPX and G100 aeroplanes with serial numbers 004 through 127 inclusive.\n\n \n\nRequirement: Unless already accomplished, adjust the main landing gear ground contact switches in accordance with the revised procedures in the G100 Maintenance Manual and GALP Service Bulletin 1125-32A-233 Revision 1 dated 1 August 2003.\n\n \n\nNote 1: The G100 Maintenance Manual procedures for adjusting the main landing gear ground contact switch were revised by Temporary Revision (TR) 32-8 dated 12 April 2001. Maintenance Manual Revision 4, dated 1 August 2001, subsequently incorporated the revised procedures and removed TR 32-8.\n\n \n\nNote 2: Israel CAA AD 32-03-08-05 refers.\n\n \n\nCompliance: Within 200 hours time in service after the effective date of this Directive This Airworthiness Directive becomes effective on 27 November 2003.\n\nBackground: The Israel Civil Aviation Administration has received reports of in-flight deployment of the ground airbrakes following lowering of the landing gear. This Directive requires the adjustment of the main landing gear ground contact switch to prevent false ‘Ground’ position signals causing the ground airbrakes to deploy and the aircraft to roll.\n\n![](image.002.png)  \n\n\nJim Coyne\n\nDelegate of the Civil Aviation Safety Authority 14 October 2003\n\n \n\n \n\n \n\n![](image.001.png)  \n\n\nThe above AD is notified in the Commonwealth of Australia Gazette on 5 November 2003.\n\n \n\n \n\n\nPage 1 of 1\n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This AD maintains its original narrow scope — a targeted safety directive for a specific mechanical issue on a limited fleet of aircraft. No scope creep is evident."},"complexity_factors":["Single, clearly defined applicability (specific aircraft serial numbers 004-127)","Single, unambiguous requirement (adjust switches per specified manual and service bulletin)","Simple compliance deadline (200 hours time in service after effective date)","No nested exceptions, conditional logic, or cross-references to other legislation","Only 2 brief explanatory notes referencing technical documents","Total length: approximately 1 page"],"plain_english_summary":"This Airworthiness Directive requires operators of Gulfstream G100/Astra jets (serials 004–127) to adjust the main landing gear ground contact switches to stop false “on-ground” signals that have led to in-flight airbrake deployment and potential loss of control. It mandates following the G100 Maintenance Manual and GALP Service Bulletin 1125-32A-233 Rev 1 within 200 flight hours of 27 Nov 2003."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The AD stays within the normal scope of an airworthiness directive: it addresses a specific unsafe condition (false ground signals causing unintended airbrake deployment) on a defined set of aeroplanes by mandating a specific corrective maintenance action. It does not expand beyond that original safety‑correction purpose (no new regulatory domains, economic instruments, or broad obligations are introduced)."},"complexity_factors":["Short document (single‑issue Airworthiness Directive)","Single prescriptive action (adjust switches) rather than multiple conditional stages","Limited applicability (specific serial numbers 004–127 inclusive)","Single compliance window (within 200 hours time in service)","Cross‑references to two external documents (G100 Maintenance Manual and GALP Service Bulletin 1125-32A-233 Rev 1) but no additional nested exceptions","Few defined terms and no layered conditional logic"],"plain_english_summary":"**What this instrument does (mechanically):**\n\n- Requires owners/operators of certain Israel Aircraft Industries (IAI) Model 1125 (Astra) series aeroplanes (serial numbers 004–127 inclusive) to adjust the main landing gear ground contact switches.\n- The adjustment must be carried out following the revised procedures contained in the G100 Maintenance Manual and in Gulfstream Aerospace (GALP) Service Bulletin 1125-32A-233 Revision 1 (dated 1 August 2003).\n- The work must be completed within 200 hours time in service after the AD’s effective date (the AD effective date is stated in the Compliance section).\n\n**Who this affects:**\n\n- Aircraft owners, operators and maintainers of GALP Model 1125 Astra, Astra SPX and G100 aeroplanes with serial numbers 004 through 127.\n- Maintenance organisations (including independent maintenance, repair and overhaul providers) that perform or sign off on the required adjustment.\n\n**Why it matters (official rationale and testing that claim):**\n\n- The Background section says there have been reports of in‑flight deployment of the ground airbrakes after landing gear extension. The stated cause is false \"Ground\" position signals from the main landing gear ground contact switches. The AD requires switch adjustment to prevent these false signals and unintended airbrake deployment (see ‘‘Background’’ and ‘‘Requirement’’ sections).\n\n**Practical effects, costs and incentives:**\n\n- Who pays: the operator/owner pays for the maintenance work (labour and any incidental materials). The AD does not mandate replacement parts, only adjustment per the manual and service bulletin (see ‘‘Requirement’’).\n- Compliance burden: a single, prescriptive maintenance action to be completed within 200 flight hours. Operators can schedule the adjustment during routine maintenance to reduce disruption. No long‑term recurring requirement is specified in this AD text.\n- Impact on service providers: independent and manufacturer‑affiliated maintenance organisations can perform the work provided they follow the maintenance manual and service bulletin procedures. The AD does not restrict who may perform the adjustment (see ‘‘Requirement’’ and Note 1 regarding where the revised procedure is recorded).\n- Safety benefit concentrated: operators of affected aeroplanes and their passengers/crew receive the direct safety benefit (preventing unintended airbrake deployment). Costs are diffuse across those operators in the form of maintenance time and expense.\n- Implementation risk and reliance: the effectiveness depends on correct execution of the revised maintenance procedures in the G100 Maintenance Manual and in GALP Service Bulletin 1125-32A-233 Rev 1 (see Note 1 and Requirement). If the procedures are ambiguous or incorrectly followed, the unsafe condition may persist.\n\n**Trade‑offs and opportunity costs:**\n\n- The AD imposes a short‑term maintenance cost and the opportunity cost of workshop time in return for reducing a flight‑safety risk. The text does not require parts purchase or recurring inspections; therefore ongoing operational costs are limited to this one corrective action unless follow‑up ADs or service instructions are later issued.\n\n**Administrative decision‑making and legal basis:**\n\n- The AD is issued under subregulation 39.1(1) of the Civil Aviation Safety Regulations 1998 (see heading). The CASA delegate determines the required corrective action and the compliance timeframe (refer to the heading and Compliance/Requirement sections).\n\n**Cross‑references and origins:**\n\n- The AD refers operators to the G100 Maintenance Manual (Temporary Revision 32‑8 incorporated into Revision 4) and Gulfstream Service Bulletin 1125-32A-233 Rev 1 for the exact adjustment procedure (see Note 1 and Requirement).\n- It also notes a corresponding Israel CAA AD (Israel CAA AD 32-03-08-05) (see Note 2), showing the directive aligns with the airworthiness authority in the aircraft’s state of manufacture.\n\n(Sections cited: Applicability; Requirement; Note 1; Note 2; Compliance; Background.)"}},"importantCases":[],"_links":{"self":"/api/acts/ad-iai-a-17-main-landing-gear-ground-contact-switches","history":"/api/acts/ad-iai-a-17-main-landing-gear-ground-contact-switches/history","analysis":"/api/acts/ad-iai-a-17-main-landing-gear-ground-contact-switches/analysis","conflicts":"/api/acts/ad-iai-a-17-main-landing-gear-ground-contact-switches/conflicts","importantCases":"/api/acts/ad-iai-a-17-main-landing-gear-ground-contact-switches/important-cases","documents":"/api/acts/ad-iai-a-17-main-landing-gear-ground-contact-switches/documents"}}