{"id":"F2006B06886","name":"AD/SD3-60/40 Amdt 1 - Flight Controls Rudder Gust Lock System","slug":"ad-sd3-60-40-amdt-1-flight-controls-rudder-gust-lock-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":114766,"registerId":"commonwealth-F2006B06886-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/SD3-60/40 Amdt 1 - Flight Controls Rudder Gust Lock System","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)  \nShort SD3-60 Series Aeroplanes\n\nAD/SD3-60/40\n\nAmdt 1\n\n  \nFlight Controls Rudder Gust Lock System 8/94\n\nDM\n\nApplicability: All SD3-60 aircraft listed in Short Brothers PLC Service Bulletin SD360-27-23 Revision No 1 dated 15 April 1994.\n\nRequirement: Modify the rudder gust lock electrical circuit in accordance with Shorts SD3-60 Service Bulletin SD360-27-23 Revision No 1 dated 15 April 1994.\n\nNote: This Service Bulletin has been classified as Mandatory by the CAA(UK).\n\nCompliance: Prior to 28 July 1994.\n\nBackground: The original issue of this Directive required the introduction of a time delay relay in the rudder gust lock electrical control circuit. This relay delays possible locking of the rudder, with the weight on wheels switch closed, if the actuator has runaway in flight.\n\nThis amendment reflects a revision to the Requirement Document, which contains minor changes to the wiring and accomplishment instructions. The compliance date is unchanged.","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The amendment does not broaden or narrow which aircraft must comply or change the compliance date. It updates the Requirement Document with minor wiring and accomplishment instruction changes; the underlying obligation to install a time‑delay relay remains (Background / Compliance)."},"complexity_factors":["Safety‑critical electrical modification: introduces a time‑delay relay affecting flight controls (Background / Requirement).","Relies on an external technical document: compliance requires following Shorts Service Bulletin SD360‑27‑23 Rev 1 (Applicability / Requirement).","Fixed compliance deadline: work must be done prior to 28 July 1994 (Compliance).","Limited applicability: only applies to SD3‑60 aircraft listed in the Service Bulletin (Applicability).","Amendment scope narrow: this change revises wiring and accomplishment instructions only; no change to compliance date (Background)."],"plain_english_summary":"Mandates modification of the rudder gust‑lock electrical circuit on Short SD3‑60 aeroplanes named in Shorts Service Bulletin SD360‑27‑23 Rev 1 (15 Apr 1994). Operators must complete the wiring change, including fitting a time‑delay relay, before 28 July 1994.\n\nThe relay delays possible rudder locking when the weight‑on‑wheels switch is closed if the actuator runs away in flight. The amendment makes only minor wiring and instruction changes; aircraft operators (owners) pay for the work and maintenance personnel implement it."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This amendment remains tightly scoped to its original purpose — modifying the rudder gust lock electrical circuit on SD3-60 aircraft. The amendment merely updates the technical implementation details while maintaining the same safety objective, applicability, and compliance deadline."},"complexity_factors":["Single, specific technical requirement referencing an external service bulletin","No defined terms section — relies entirely on external technical document","No conditional logic or nested exceptions","Very short document (approximately 150 words of substantive text)","Single compliance date with no alternative methods or phased implementation","Straightforward applicability test (aircraft listed in specific service bulletin)"],"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) for specific aircraft.\n\n**What it does:** It requires owners or operators of **Short SD3-60 series aeroplanes** (a type of regional turboprop aircraft) to modify the electrical wiring for the **rudder gust lock system**.\n\n**Why it matters:** The rudder gust lock is a safety device that prevents the rudder (the vertical tail surface that steers the aircraft left/right) from moving around in high winds when the plane is parked. However, if this system malfunctions and tries to lock the rudder *while the aircraft is flying*, it could cause a serious accident. This modification adds a **time delay relay** — a safety switch that waits before activating — to prevent accidental in-flight locking if the system experiences an electrical \"runaway\" (uncontrolled activation).\n\n**Who must comply:** Anyone operating SD3-60 aircraft covered by the specific service bulletin mentioned. They had to complete this modification before 28 July 1994.\n\n**What's changed in this version:** This is **Amendment 1** to the original directive. It updates the technical instructions for the wiring modification but keeps the same safety purpose and deadline."}},"importantCases":[],"_links":{"self":"/api/acts/ad-sd3-60-40-amdt-1-flight-controls-rudder-gust-lock-system","history":"/api/acts/ad-sd3-60-40-amdt-1-flight-controls-rudder-gust-lock-system/history","analysis":"/api/acts/ad-sd3-60-40-amdt-1-flight-controls-rudder-gust-lock-system/analysis","conflicts":"/api/acts/ad-sd3-60-40-amdt-1-flight-controls-rudder-gust-lock-system/conflicts","importantCases":"/api/acts/ad-sd3-60-40-amdt-1-flight-controls-rudder-gust-lock-system/important-cases","documents":"/api/acts/ad-sd3-60-40-amdt-1-flight-controls-rudder-gust-lock-system/documents"}}