{"id":"F2006B09877","name":"AD/F50/5 - Cabin Pressure Control System","slug":"ad-f50-5-cabin-pressure-control-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":54997,"registerId":"commonwealth-F2006B09877-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/F50/5 - Cabin Pressure Control System","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 F50 (F27 Mk 50) Series Aeroplanes\n\n \n\nAD/F50/5 Cabin Pressure Control System 1/89\n\nApplicability: All F27 Mk 50 aircraft serial numbers 20104 to 20108 inclusive, and 20110 to 20112 inclusive.\n\n \n\nRequirement: Action in accordance with the initial issue of Fokker SB F50-21-002.\n\n \n\nNote: Dutch AD BLA 88-89 refers.\n\n \n\nCompliance: Prior to 26 April 1989.\n\n \n\nBackground:  The current cabin pressurization system configuration is such that a positive cabin pressure differential can exist on the ground, and can cause the cabin door to blow open when released by ground staff thus potentially damaging the aircraft and injuring personnel.\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 AD's scope is limited to the listed serial numbers and requires action per the manufacturer's service bulletin to address a specific cabin pressurisation issue (Applicability; Requirement; Background). There is no indication in the text that the AD expanded or narrowed that scope from an earlier or different intent; it implements the stated corrective action for the identified aircraft within a fixed compliance period (Compliance)."},"complexity_factors":["Narrow and specific applicability limited to seven serial numbers (Applicability)","Compliance action is delegated to a single manufacturer's service bulletin rather than containing technical steps in the AD (Requirement)","Short, fixed compliance deadline (Compliance)","Safety risk described is straightforward and specific (Background)","Minimal legal wording and few cross-references in the instrument","Operational complexity depends on technical content of the referenced service bulletin, which is not included in the AD text"],"plain_english_summary":"This AD requires owners/operators of specific Fokker F50 (F27 Mk 50) serial numbers to carry out the manufacturer's Service Bulletin F50-21-002—mandated by the Civil Aviation Safety Authority—to eliminate a cabin pressurisation condition that can cause a door to blow open on the ground. Compliance (at operators’ expense) must be completed by 26 April 1989; it trades short-term downtime and costs for reduced risk to passengers, crew and ground staff."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, time-bound safety directive with a narrow, specific scope (particular aircraft serial numbers, single system, single technical fix). There is no indication of scope creep; it addresses exactly the safety issue described in the background."},"complexity_factors":["Very short document (under 200 words)","Single, clearly defined applicability clause (specific serial numbers)","One simple requirement referencing an external technical document","No defined terms section","No conditional logic or nested exceptions","Clear, single compliance deadline","Background explanation is plain language and intuitive"],"plain_english_summary":"**What this is:** This is an Airworthiness Directive (AD) — essentially a mandatory safety fix ordered by Australia's Civil Aviation Safety Authority (CASA) for a specific aircraft type.\n\n**What it does:** It requires owners or operators of certain Fokker F50 aeroplanes to modify their cabin pressure control system. The problem is that the existing system can trap pressurised air inside the cabin even when the plane is on the ground. If ground crew open the door in this state, the sudden release of pressure can blow the door open violently — risking injury to people nearby and damage to the aircraft.\n\n**Who it affects:** Anyone operating Fokker F50 aircraft with serial numbers 20104–20108 and 20110–20112. These operators must follow the manufacturer's service bulletin (Fokker SB F50-21-002) to fix the issue.\n\n**Why it matters:** This is a straightforward safety measure to prevent physical injuries to ground handling staff and avoid costly aircraft damage. The fix had to be completed before 26 April 1989."}},"importantCases":[],"_links":{"self":"/api/acts/ad-f50-5-cabin-pressure-control-system","history":"/api/acts/ad-f50-5-cabin-pressure-control-system/history","analysis":"/api/acts/ad-f50-5-cabin-pressure-control-system/analysis","conflicts":"/api/acts/ad-f50-5-cabin-pressure-control-system/conflicts","importantCases":"/api/acts/ad-f50-5-cabin-pressure-control-system/important-cases","documents":"/api/acts/ad-f50-5-cabin-pressure-control-system/documents"}}