{"id":"F2006B10153","name":"AD/GA-7/9 - Rudder Torque Tube Corrosion and Cracking","slug":"ad-ga-7-9-rudder-torque-tube-corrosion-and-cracking","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":55739,"registerId":"commonwealth-F2006B10153-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/GA-7/9 - Rudder Torque Tube Corrosion and Cracking","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 Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Gulfstream (Grumman American) GA-7 Series Aeroplanes\n\n \n\nAD/GA-7/9 Rudder Torque Tube Corrosion and Cracking 1/86 T\n\nApplicability: All models.\n\n \n\nRequirement: Action in accordance with Gulfstream Aerospace Corp, SB No ME-21.\n\n \n\nCompliance: Within 10 hours time in service after 04 December 1985 and thereafter at intervals not exceeding 100 hours time in service or at each issue of a new Maintenance Release.\n\n \n\nBackground:  The manufacturer reports instances of corrosion and cracking in the rudder torque tube at the bellcrank area. In two aircraft the torque tube had cracked around the entire circumference of the tube.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspections for rudder torque tube corrosion."},"complexity_factors":["Very short document (under 200 words)","Only 4 defined elements: applicability, requirement, compliance, and background","Single, clear compliance pathway with two alternative triggers (100 hours OR new Maintenance Release)","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","No nested conditions or exceptions","Straightforward mechanical safety issue with prescribed manufacturer procedure"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) for specific aircraft.\n\n**What it does:** It requires owners and operators of **Gulfstream GA-7 series aeroplanes** (also known as Grumman American GA-7s) to inspect the **rudder torque tube** — a metal tube that transfers pilot pedal movements to the rudder — for **corrosion and cracking** near where it connects to a component called the bellcrank.\n\n**Why it matters:** The manufacturer found cases where this tube had corroded and cracked completely around its circumference. A failed torque tube means the pilot could lose rudder control, which is critical for steering the aircraft, especially during takeoff, landing, and crosswinds.\n\n**What must be done:**\n- **First inspection:** Within 10 flight hours after 4 December 1985\n- **Repeat inspections:** Every 100 flight hours **or** whenever a new Maintenance Release is issued (whichever comes first)\n- **How:** Follow the manufacturer's Service Bulletin ME-21 exactly\n\n**Who it affects:** Anyone who owns, operates, or maintains a Gulfstream/Grumman American GA-7 aircraft in Australia."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to all GA-7 models and mandates inspections/repairs per SB No ME-21 on a defined schedule. Nothing in the text indicates an expansion or narrowing of the AD's applicability or requirements compared with the directive as stated here."},"complexity_factors":["Narrow technical focus (single component: rudder torque tube) and single corrective reference (SB No ME-21).","Short, specific compliance timeline (initial 10 hours then every 100 hours or at each Maintenance Release).","Mandated compliance with an external document (service bulletin) creates dependence on that document for procedural detail.","Limited scope of discretion in the AD text (no alternative compliance methods or exemptions provided).","Operational implications (recurring inspections) that interact with maintenance scheduling and downtime considerations."],"plain_english_summary":"Owners and operators of all Gulfstream (Grumman American) GA‑7 series aeroplanes must carry out the inspection and repair actions specified in Gulfstream Service Bulletin No. ME‑21 within 10 hours TIS after 4 December 1985 and thereafter at intervals not exceeding 100 hours TIS or each Maintenance Release. The AD responds to reported corrosion and circumferential cracking of the rudder torque tube; it imposes recurring maintenance, downtime and direct costs to detect and correct that safety risk, with no alternative compliance routes specified."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ga-7-9-rudder-torque-tube-corrosion-and-cracking","history":"/api/acts/ad-ga-7-9-rudder-torque-tube-corrosion-and-cracking/history","analysis":"/api/acts/ad-ga-7-9-rudder-torque-tube-corrosion-and-cracking/analysis","conflicts":"/api/acts/ad-ga-7-9-rudder-torque-tube-corrosion-and-cracking/conflicts","importantCases":"/api/acts/ad-ga-7-9-rudder-torque-tube-corrosion-and-cracking/important-cases","documents":"/api/acts/ad-ga-7-9-rudder-torque-tube-corrosion-and-cracking/documents"}}