{"id":"F2006B03641","name":"AD/BEECH 1900/24 - Ground Fine Switch","slug":"ad-beech-1900-24-ground-fine-switch","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43231,"registerId":"commonwealth-F2006B03641-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 1900/24 - Ground Fine Switch","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBeechcraft 1900 Series Aeroplanes\n\nAD/BEECH 1900/24 Ground Fine Switch 10/98\n\nApplicability: Model 1900D aeroplanes with serial numbers UE-1 through UE-271 inclusive. Requirement: Modify the ground idle low pitch stop system by incorporating Raytheon ‘Ground\n\nFine Switch Installation Kit’ No 129-5200-1 in accordance with the Accomplishment\n\nInstructions of Raytheon Aircraft Mandatory Service Bulletin No 2714 issued June 1997.\n\nNote: FAA AD 98-13-11 Amdt 39-10599 refers.\n\nCompliance: Within 800 hours time in service after the effective date of this directive.\n\nThis airworthiness directive becomes effective on 10 September 1998.\n\nBackground: This directive is intended to prevent a loose or misrigged ground fine switch, which could result in a hard landing causing structural damage to the airframe and possible passenger injury.","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, single-issue airworthiness directive targeting a specific mechanical defect in a defined aircraft population. It has not expanded beyond its original safety purpose."},"complexity_factors":["Single, specific mechanical modification with no conditional exceptions","Only one defined applicability criterion (serial number range)","Clear, single compliance deadline (800 hours time in service)","No cross-references to other legislation beyond a single related FAA directive mentioned in a note","No nested definitions or interpretive provisions","Straightforward causal chain: faulty switch → hard landing → damage/injury → mandatory fix"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). Think of it like a compulsory recall notice, but for aircraft rather than cars.\n\n**What it does:** It requires owners and operators of specific Beechcraft 1900D aeroplanes (those with serial numbers UE-1 through UE-271) to install a safety modification. The fix involves adding a \"Ground Fine Switch Installation Kit\" to the aircraft's ground idle system — the mechanism that controls propeller pitch when the plane is on the ground.\n\n**Why it matters:** A faulty or poorly installed ground fine switch could cause a hard landing. This means the plane might hit the runway harder than intended, potentially damaging the airframe and injuring passengers. The directive prevents this by ensuring the switch is properly secured.\n\n**Who must comply:** Anyone operating the affected Beechcraft 1900D models must complete this modification within 800 flight hours of 10 September 1998.\n\n**Key details:**\n- **Affected aircraft:** Beechcraft 1900D, serial numbers UE-1 to UE-271\n- **Required action:** Install Raytheon kit No 129-5200-1 following specific instructions in Service Bulletin No 2714\n- **Deadline:** Within 800 hours of flying time after 10 September 1998\n- **Related rule:** This aligns with a US Federal Aviation Administration (FAA) directive (AD 98-13-11)"},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive as written applies to Model 1900D aeroplanes serial numbers UE-1 through UE-271 and requires installation of the named Raytheon kit per the manufacturer’s mandatory service bulletin within 800 hours time in service. The text contains no indication that the scope of applicability or the required modification has been broadened or narrowed from the document’s stated content."},"complexity_factors":["Narrow technical applicability (specific model and serial-number range)","Prescriptive compliance method naming a specific kit and mandatory service bulletin","Compliance measured in aircraft hours-in-service (800 hours) rather than calendar time","Cross-reference to an external FAA AD and manufacturer service bulletin for accomplishment instructions","Lack of stated alternatives, exemptions, or cost allocation details in the text"],"plain_english_summary":"This directive requires owners/operators of Beechcraft 1900D aeroplanes (serials UE‑1 through UE‑271) to install Raytheon Ground Fine Switch Kit No. 129‑5200‑1 per Raytheon Mandatory Service Bulletin No. 2714 within 800 hours TIS after 10 September 1998 to prevent a loose or mis‑rigged ground fine switch that could cause hard landings, damage or injury.\n\nOperators must procure and pay for the kit and installation; the rule is prescriptive with limited timing discretion and no alternate means of compliance specified."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-1900-24-ground-fine-switch","history":"/api/acts/ad-beech-1900-24-ground-fine-switch/history","analysis":"/api/acts/ad-beech-1900-24-ground-fine-switch/analysis","conflicts":"/api/acts/ad-beech-1900-24-ground-fine-switch/conflicts","importantCases":"/api/acts/ad-beech-1900-24-ground-fine-switch/important-cases","documents":"/api/acts/ad-beech-1900-24-ground-fine-switch/documents"}}