{"id":"F2006B02794","name":"AD/B727/9 Amdt 1 - Main Landing Gear Safety Bar - Modification","slug":"ad-b727-9-amdt-1-main-landing-gear-safety-bar-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":42136,"registerId":"commonwealth-F2006B02794-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/B727/9 Amdt 1 - Main Landing Gear Safety Bar - Modification","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 727 Series Aeroplanes\n\n \n\nAD/B727/9\n\nAmdt 1\n\n\nMain Landing Gear Safety Bar - Modification 2/66\n\n \n\nApplicability: All models.\n\n \n\nDocument: Boeing SB No. 32-55, Rev. 1. Compliance:  Before 6000 hours total time in service.\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\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a standard, narrow airworthiness directive focused on a specific mechanical modification. It has not expanded beyond its original safety purpose."},"complexity_factors":["Extremely short document (approximately 150 words)","Only 1 defined term implicitly referenced (Boeing SB No. 32-55)","No cross-references to other legislation beyond the enabling Civil Aviation Regulations 1998","Single, unambiguous compliance requirement (time-based deadline)","No conditional logic, exceptions, or nested provisions","Straightforward applicability (all models, no exclusions)"],"plain_english_summary":"This is an **Airworthiness Directive** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA). It requires owners and operators of **Boeing 727 aircraft** to modify the **main landing gear safety bar** (a mechanical component that helps secure the landing gear in place).\n\n**What must be done:**\n- Follow the instructions in **Boeing Service Bulletin No. 32-55, Revision 1** (the manufacturer's official technical guide for this fix)\n- Complete the modification **before the aircraft reaches 6,000 hours of total flight time**\n\n**Who it affects:**\n- All Boeing 727 models operating in Australia\n- Airlines, cargo operators, or private owners flying this aircraft type\n\n**Why it matters:**\nLanding gear failures can be catastrophic. This directive addresses a specific safety risk with the main landing gear safety bar to prevent potential accidents during takeoff or landing."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":true,"description":"The document is labelled 'Amdt 1', indicating it amends a prior airworthiness directive (AD/B727/9). The supplied text does not include the original version of the AD, so the precise nature of the amendment cannot be determined from the material provided. The amendment as presented sets applicability to 'All models', cites Boeing SB No. 32-55, Rev. 1 as the method, and imposes a compliance deadline of before 6,000 hours total time in service."},"complexity_factors":["Mandatory reference to an external technical document (Boeing SB No. 32-55, Rev. 1) means the AD’s technical details are not self-contained and require access to the service bulletin.","Compliance deadline measured in hours total time in service requires accurate tracking of each aircraft’s flight hours and scheduling of work before a moving threshold.","Applicability to all Boeing 727 models increases the number and variety of operators and maintenance circumstances affected.","The supplied text does not include the technical steps, parts lists or acceptance criteria; implementers must interpret and follow the referenced SB to resolve technical ambiguities.","Operational and logistical factors (parts availability, qualified labour, maintenance windows) can create practical complexity even though the directive’s wording is short and prescriptive."],"plain_english_summary":"CASA mandates a modification to the main landing-gear safety bar on all Boeing 727 series aeroplanes, to be carried out per Boeing Service Bulletin No. 32‑55 Revision 1 before each aeroplane reaches 6,000 hours total time in service. Operators/owners must arrange, pay for and schedule the work (and track TIS); the bulletin contains the technical steps and acceptance criteria."}},"importantCases":[],"_links":{"self":"/api/acts/ad-b727-9-amdt-1-main-landing-gear-safety-bar-modification","history":"/api/acts/ad-b727-9-amdt-1-main-landing-gear-safety-bar-modification/history","analysis":"/api/acts/ad-b727-9-amdt-1-main-landing-gear-safety-bar-modification/analysis","conflicts":"/api/acts/ad-b727-9-amdt-1-main-landing-gear-safety-bar-modification/conflicts","importantCases":"/api/acts/ad-b727-9-amdt-1-main-landing-gear-safety-bar-modification/important-cases","documents":"/api/acts/ad-b727-9-amdt-1-main-landing-gear-safety-bar-modification/documents"}}