{"id":"F2006B08428","name":"AD/CESSNA 550/22 - Outflow Safety Valve","slug":"ad-cessna-550-22-outflow-safety-valve","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115907,"registerId":"commonwealth-F2006B08428-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 550/22 - Outflow Safety Valve","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)  Cessna 550 (Citation II) Series Aeroplanes\n\n \n\nAD/CESSNA 550/22 Outflow Safety Valve 5/96\n\nApplicability: All Cessna 550 series aircraft.\n\n \n\nRequirement: Unless previously carried out, action in accordance with Allied Signal Service Bulletin 103576-21-4056.\n\n \n\nNote: FAA AD 95-25-10 Amdt 39-9456 refers.\n\n \n\nCompliance: Within 200 hours time in service from 25 April 1996 or prior to 31 July 1996, whichever occurs first.\n\n \n\nBackground: The manufacturer has advised that cracking has been found in two valve poppets of a particular batch. This cracking may cause failure of the outflow safety valve which could result in rapid decompression of the aircraft.\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, targeted safety directive addressing a specific mechanical defect in a specific aircraft type. It has not expanded beyond its original purpose of mandating inspection/replacement of cracked outflow safety valves."},"complexity_factors":["Very short document (approximately 150 words of substantive content)","Only 1 defined term implicitly referenced (the service bulletin)","No cross-references to other legislation beyond a note about a related FAA directive","Simple conditional structure: single requirement with single compliance deadline","No nested exceptions or complex logical operators","Straightforward applicability (all aircraft in the series)","Single mechanical action required (follow the service bulletin)"],"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 aircraft owners or operators to fix a specific mechanical problem.\n\n**Who it affects:** Anyone who owns or operates a **Cessna 550 series aircraft** (also known as the Citation II business jet).\n\n**What it requires:** Operators must inspect or replace the **outflow safety valve** — a component that helps regulate cabin pressure — following instructions in a manufacturer service bulletin (Allied Signal Service Bulletin 103576-21-4056). The outflow safety valve prevents the aircraft cabin from losing pressure too quickly; if it fails, passengers and crew could face **rapid decompression** (a dangerous sudden loss of breathable air at high altitude).\n\n**Why it matters:** The manufacturer discovered **cracks in valve poppets** (small moving parts inside the valve) from a specific production batch. These cracks could cause the valve to fail completely. The directive forces operators to address this before the valve breaks, preventing potential emergencies where the cabin could rapidly lose pressure.\n\n**When it had to be done:** By whichever came first — within **200 flight hours** after 25 April 1996, or before **31 July 1996**.\n\n**Key point:** This is not optional. Airworthiness Directives are legally binding safety requirements. Ignoring them means the aircraft cannot legally fly."},"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The directive applies to all Cessna 550 series aircraft and mandates the corrective action described in Allied Signal Service Bulletin 103576-21-4056 within a defined timeframe. The AD does not expand or narrow the population of affected aircraft beyond the Applicability statement, nor does it add new categories of obligation beyond requiring the service-bulletin action; therefore the scope has not changed from the instrument's stated purpose of addressing outflow safety valve poppet cracking. (Applicability, Requirement, Compliance, Background)"},"complexity_factors":["Cross-reference to an external technical document (Allied Signal Service Bulletin 103576-21-4056) — requires operators to obtain and follow another source for the exact corrective steps (Requirement).","Short, fixed compliance window (200 hours TIS from 25 April 1996 or before 31 July 1996) creates scheduling pressure for operators (Compliance).","Technical nature of the required work — requires certified maintenance personnel and possibly specific parts, creating logistical complexity for operators (Requirement).","Universal applicability to all Cessna 550 aircraft simplifies scope but increases aggregate operational impact for the fleet (Applicability).","Reference to another regulator's AD (FAA AD 95-25-10) may require cross-checking between documents for full technical or compliance context (Note)."],"plain_english_summary":"CASA mandates that every Cessna 550 (Citation II) have the outflow safety valve inspected/rectified per Allied Signal Service Bulletin 103576-21-4056, to be done within 200 flight hours from 25 April 1996 or by 31 July 1996 (whichever is earlier). Owners/operators bear parts, labour and downtime; certificated maintenance organisations must perform the work and CASA enforces compliance.\n\nThe action responds to reported poppet cracking that could cause valve failure and rapid decompression, trading short‑term cost and scheduling burdens for reduced decompression risk."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-550-22-outflow-safety-valve","history":"/api/acts/ad-cessna-550-22-outflow-safety-valve/history","analysis":"/api/acts/ad-cessna-550-22-outflow-safety-valve/analysis","conflicts":"/api/acts/ad-cessna-550-22-outflow-safety-valve/conflicts","importantCases":"/api/acts/ad-cessna-550-22-outflow-safety-valve/important-cases","documents":"/api/acts/ad-cessna-550-22-outflow-safety-valve/documents"}}