{"id":"F2006B03184","name":"AD/B747/29 - Fairing Mounted Escape Slide Firing Mechanism - Rigging Revision","slug":"ad-b747-29-fairing-mounted-escape-slide-firing-mechanism-rigging-revision","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42556,"registerId":"commonwealth-F2006B03184-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B747/29 - Fairing Mounted Escape Slide Firing Mechanism - Rigging Revision","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)  Boeing 747 Series Aeroplanes\n\n \n\nAD/B747/29 Fairing Mounted Escape Slide Firing\n\nMechanism - Rigging Revision\n\n\n12/81\n\n \n\nApplicability: All model B747 aeroplanes with S/Nos. referenced in Boeing SB 747-25A2581 or with S/Nos. referenced in subsequent issues or revisions of that SB.\n\n \n\nDocument: Boeing SB 747-25A2581.\n\n \n\nCompliance: Within 1200 hours time in service after 31 December 1981.\n\n \n\nBackground: Failure of escape slide to inflate due to reduced fairing door travel restricting the inflation firing mechanism.\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":{"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The text of the directive sets applicability, references the Boeing service bulletin for the required work, and specifies a compliance interval. It does not indicate any change to the scope from an earlier stated intent within the provided text; the AD applies to the listed B747 serial numbers and mandates the rigging revision within the stated time window (Applicability; Document; Compliance)."},"complexity_factors":["Narrow applicability tied to serial numbers listed in Boeing SB 747-25A2581 (Applicability)","Procedural detail delegated to an external manufacturer service bulletin rather than contained in the AD (Document)","Compliance measured in flight hours after a specific calendar date, requiring operational tracking (Compliance)","Technical cause is a mechanical interference (reduced fairing door travel) affecting safety-critical equipment (Background)","Implementation requires typical maintenance access and scheduling but no additional regulatory steps are described in the AD itself (Document; Compliance)"],"plain_english_summary":"### What this directive does\n\nThis airworthiness directive requires a rigging revision to the fairing-mounted escape slide firing mechanism on certain Boeing 747 aeroplanes. The technical work is to be performed in accordance with Boeing Service Bulletin 747-25A2581 (or later revisions of that bulletin), which contains the procedural details (Document).\n\n### Who this affects\n\n- Operators and owners of Boeing 747 aeroplanes whose serial numbers are listed in Boeing SB 747-25A2581 or in later issues or revisions of that SB (Applicability).\n\n### When it must be done\n\n- The required rigging revision must be completed within 1,200 hours time in service after 31 December 1981 (Compliance).\n\n### Why it matters (official rationale and mechanical effect)\n\n- The stated reason is that reduced fairing door travel can restrict the escape slide inflation firing mechanism, which has resulted in failure of an escape slide to inflate (Background). The rigging revision changes how the fairing and firing mechanism are adjusted so that the door travel does not interfere with the firing mechanism and so that the slide will deploy as designed.\n\n### Who decides and who pays\n\n- The directive places the obligation on the operator/owner of an affected aeroplane to have the work done within the specified compliance interval (Applicability; Compliance). The procedural instructions are those contained in the referenced Boeing service bulletin (Document). Practically, the operator must schedule and fund the maintenance action and ensure it is done according to the SB.\n\n### Practical trade-offs, compliance and implementation points to note\n\n- The directive refers out to a manufacturer service bulletin for the exact work instructions; the AD itself sets applicability and a compliance window but does not contain the step-by-step procedure (Document).\n- Compliance is measured in aircraft time-in-service hours after a fixed calendar date, so operators must track hours to meet the 1,200-hour deadline (Compliance).\n- The safety concern identified is mechanical interference from reduced fairing door travel that can prevent slide inflation; the required change is a rigging revision intended to restore prescribed travel and firing operation (Background).\n\nSections cited from the directive: Applicability; Document; Compliance; Background."},"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 ensuring escape slide reliability on affected Boeing 747 aircraft."},"complexity_factors":["Extremely short document — only 8 substantive lines of regulatory text","No defined terms section — relies entirely on external Boeing technical document","Single, unambiguous compliance deadline (1200 hours after fixed date)","No nested conditions, exceptions, or cross-references to other legislation","Simple binary applicability test (serial number match)","Background explanation is one plain-English sentence"],"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 Boeing 747 aircraft.\n\n**What it does:** It requires airlines and aircraft operators to fix a dangerous design flaw in the emergency escape slide system on certain Boeing 747 planes.\n\n**The problem:** On some 747s, the escape slides mounted on the aircraft's fairings (the smooth outer panels covering doors and hatches) weren't inflating properly during emergencies. This happened because the fairing doors weren't opening far enough — their travel was restricted — which prevented the firing mechanism from activating the inflation system. In plain terms: passengers trying to evacuate could find themselves staring at a deflated slide instead of an inflated escape route.\n\n**Who must comply:** All Boeing 747 aircraft with specific serial numbers listed in Boeing Service Bulletin 747-25A2581 (or later versions of that document).\n\n**What operators must do:** Follow the technical instructions in Boeing Service Bulletin 747-25A2581 to correct the rigging (the mechanical setup) of the firing mechanism. This must be done within 1,200 flight hours after 31 December 1981.\n\n**Why it matters:** Emergency evacuation systems must work flawlessly. A slide that fails to inflate during an emergency evacuation could trap passengers inside a burning or damaged aircraft, turning a survivable incident into a fatal one."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b747-29-fairing-mounted-escape-slide-firing-mechanism-rigging-revision","history":"/api/acts/ad-b747-29-fairing-mounted-escape-slide-firing-mechanism-rigging-revision/history","analysis":"/api/acts/ad-b747-29-fairing-mounted-escape-slide-firing-mechanism-rigging-revision/analysis","conflicts":"/api/acts/ad-b747-29-fairing-mounted-escape-slide-firing-mechanism-rigging-revision/conflicts","importantCases":"/api/acts/ad-b747-29-fairing-mounted-escape-slide-firing-mechanism-rigging-revision/important-cases","documents":"/api/acts/ad-b747-29-fairing-mounted-escape-slide-firing-mechanism-rigging-revision/documents"}}