{"id":"F2006B09696","name":"AD/F27/129 - Brake Control Valve Actuating Levers","slug":"ad-f27-129-brake-control-valve-actuating-levers","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115854,"registerId":"commonwealth-F2006B09696-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F27/129 - Brake Control Valve Actuating Levers","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)  Fokker F27 Series Aeroplanes\n\n \n\nAD/F27/129 Brake Control Valve Actuating Levers 3/92\n\nApplicability: All model F27, all serial numbers.\n\n \n\nRequirement: Replace the brake control valve actuating levers in accordance with Fokker SB F27/32-161 Revision 1 dated 14 June 1991.\n\n \n\nNote: Netherlands RLD AD 91-038 refers.\n\n \n\nCompliance: Before 1 May 1992.\n\n \n\nBackground: Country of origin AD. Reports have been received of brake control valve actuating levers that fractured during operation of the braking system. Subsequent investigation showed that the levers initially cracked due to fatigue and finally fractured due to overload.\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 discrete, time-bound safety directive. It has not expanded beyond its original purpose of mandating a specific hardware replacement on a specific aircraft type."},"complexity_factors":["Single, unambiguous requirement with no conditional exceptions","No defined terms section — uses plain technical language","Single cross-reference to manufacturer service bulletin and Dutch aviation authority document","Fixed compliance date with no alternative methods or phased implementation","Extremely short document (under 200 words of substantive content)"],"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) for aircraft.\n\n**What it does:** It requires owners and operators of all Fokker F27 aircraft (a Dutch-built regional turboprop) to replace specific brake parts — the \"brake control valve actuating levers\" — before 1 May 1992.\n\n**Why it matters:** The original brake levers were cracking and breaking due to metal fatigue. If a lever fractures during landing, the brakes could fail, potentially causing a runway accident. This directive forces a fix before the problem causes a crash.\n\n**Who must comply:** Anyone operating a Fokker F27 in Australia, regardless of when it was built or its serial number.\n\n**How to comply:** Follow the manufacturer's service bulletin (Fokker SB F27/32-161 Revision 1, dated 14 June 1991) to install replacement levers."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive does not change regulatory scope beyond imposing a corrective airworthiness action on an identified fleet. It mandates a part replacement for all F27 aeroplanes (Applicability; Requirement) with a fixed compliance date (Compliance). There is no expansion or narrowing of the set of affected aircraft or of ongoing operational permissions in the text of this instrument."},"complexity_factors":["Single, specific mandated action with a single clear compliance date (Requirement; Compliance)","Uniform applicability to all F27 models and serial numbers (Applicability) reduces case-by-case interpretation","Dependence on an external manufacturer service bulletin for technical steps increases logistical complexity (Requirement)","Reference to a foreign authority AD (Netherlands RLD AD 91-038) introduces an additional external document to consult (Note)","Technical work must be performed by qualified maintenance organisations, creating operational and scheduling complexity not detailed in the directive (implicit from Requirement)"],"plain_english_summary":"This directive mandates replacement of brake control valve actuating levers on all Fokker F27 aircraft, to be done per Fokker Service Bulletin F27/32-161 Rev.1 and completed by 1 May 1992. Owners/operators must arrange and pay for the work, normally via licensed maintenance providers.\n\nIt was issued after reports of fatigue cracks and overload fractures in the levers. Practical impacts: parts/labour cost, aircraft downtime, reliance on the service bulletin and parts supply."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f27-129-brake-control-valve-actuating-levers","history":"/api/acts/ad-f27-129-brake-control-valve-actuating-levers/history","analysis":"/api/acts/ad-f27-129-brake-control-valve-actuating-levers/analysis","conflicts":"/api/acts/ad-f27-129-brake-control-valve-actuating-levers/conflicts","importantCases":"/api/acts/ad-f27-129-brake-control-valve-actuating-levers/important-cases","documents":"/api/acts/ad-f27-129-brake-control-valve-actuating-levers/documents"}}