{"id":"F2006B10891","name":"AD/JETSTREAM/23 Amdt 1 - Gust Lock/Throttle Interlock","slug":"ad-jetstream-23-amdt-1-gust-lock-throttle-interlock","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56424,"registerId":"commonwealth-F2006B10891-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JETSTREAM/23 Amdt 1 - Gust Lock/Throttle Interlock","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)  British Aerospace BAe 3100 (Jetstream) Series Aeroplanes\n\n \n\nAD/JETSTREAM/23\n\nAmdt 1\n\n\nGust Lock/Throttle Interlock 2/89 DM\n\n \n\nApplicability: Series 3100 constructors numbers 601 to 749. Requirement: Action in accordance with BAe SB 27-JM7561 Rev 1. Compliance:               Prior to 30 April 1989.\n\nBackground: There has been an incident where take-off was attempted with the rudder gust lock partially engaged. Incorporation of this SB ensures that take-off power cannot be achieved without all three gust locks having been disengaged. Rev 1 of the Service Bulletin provides amended rigging instructions for those aircraft that could not physically meet the initial requirement.\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":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD retains the same population of affected aircraft (constructors numbers 601–749) and the same safety objective (prevent take-off power when gust locks are engaged). Revision 1 of the Service Bulletin changed the implementation details (amended rigging instructions for aircraft that could not physically meet the initial requirement) but did not change the applicability or the compliance deadline stated in the AD (see \"Background\" and \"Requirement\")."},"complexity_factors":["Narrow applicability limited to BAe 3100 constructors numbers 601–749 (straightforward population). (Applicability)","Dependency on an external document (BAe Service Bulletin 27-JM7561 Rev 1) for technical implementation increases practical complexity. (Requirement)","Technical rigging work and possible aircraft-specific adjustments where original instructions could not be met add implementation complexity for some airframes. (Background)","Fixed compliance deadline creates scheduling pressure for operators and maintenance organisations. (Compliance)","Regulatory enforcement and certification of the work require maintenance record changes and authority oversight (implied by AD framework header)."],"plain_english_summary":"This AD requires owners/operators of BAe Jetstream Series 3100 aeroplanes (c/n 601–749) to modify the engine/throttle system per BAe Service Bulletin 27-JM7561 Rev 1 so take-off power cannot be achieved while any gust lock is engaged. It was issued after an attempted take-off with a partially engaged gust lock; operators must arrange and pay for the work and comply by 30 April 1989."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive addressing a specific mechanical hazard. It has not expanded beyond its original purpose of mandating the gust lock/throttle interlock modification for the identified aircraft series."},"complexity_factors":["Single, specific applicability (one aircraft type, defined serial number range)","One clear compliance action (follow the referenced Service Bulletin)","No defined terms section","No cross-references to other legislation or regulations beyond the parent Civil Aviation Regulations 1998","Simple conditional logic (if aircraft in this range, then must comply)","Background explanation provided in plain language","Single deadline with no exceptions or extensions mentioned"],"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) that requires specific repairs or modifications to aircraft.\n\n**What it does:** It orders owners and operators of specific British Aerospace Jetstream 3100 series aircraft (serial numbers 601 to 749) to install a safety modification. This modification creates an **interlock** (a mechanical connection that prevents one action unless another condition is met) between the throttle (power control) and the three \"gust locks\" (devices that hold control surfaces like the rudder steady when the plane is parked).\n\n**Why it matters:** A previous incident occurred where a pilot attempted to take off with the rudder gust lock still partially engaged — a dangerous situation that could cause loss of control. This directive ensures that **take-off power cannot be applied unless all three gust locks are fully disengaged**, preventing similar accidents. The amendment (Rev 1) provides updated installation instructions for aircraft that couldn't physically meet the original technical requirements.\n\n**Who must comply:** Operators of affected Jetstream aircraft had to complete this modification **before 30 April 1989**."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jetstream-23-amdt-1-gust-lock-throttle-interlock","history":"/api/acts/ad-jetstream-23-amdt-1-gust-lock-throttle-interlock/history","analysis":"/api/acts/ad-jetstream-23-amdt-1-gust-lock-throttle-interlock/analysis","conflicts":"/api/acts/ad-jetstream-23-amdt-1-gust-lock-throttle-interlock/conflicts","importantCases":"/api/acts/ad-jetstream-23-amdt-1-gust-lock-throttle-interlock/important-cases","documents":"/api/acts/ad-jetstream-23-amdt-1-gust-lock-throttle-interlock/documents"}}