{"id":"F2009L03815","name":"AD/CESSNA 550/13 - Bleed Air Check Valve - CANCELLED","slug":"ad-cessna-550-13-bleed-air-check-valve-cancelled","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":81055,"registerId":"commonwealth-F2009L03815-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Cessna 550 (Citation II) Series Aeroplan","sectionType":"division","heading":"Cessna 550 (Citation II) Series Aeroplanes","content":"### Cessna 550 (Citation II) Series Aeroplanes\n\n| AD/CESSNA 550/13 | Bleed Air Check Valve | 12/2009 |\n| ---------------- | --------------------- | ------- |\n\n| Requirement: | CANCELLED.                                                                                                                                                                                                                                                                                                                                    |\n| ------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |\n|              | This AD is cancelled on 19 November 2009.                                                                                                                                                                                                                                                                                                     |\n| Background:  | This AD, raised in1986 against Cessna Service Bulletins (SB) SB 550-36-2 and SBS550-36-1, required a modification by replacement of bleed air check valve. Compliance was required at the next scheduled maintenance period after30 September 1986.As all affected aircraft would have been modified long ago, this AD is no longer required. |\n\n![](image.001.png)\n\nDavid Villiers  \nDelegate of the Civil Aviation Safety Authority\n\n27 September 2009","sortOrder":0},{"sectionNumber":"AD/CESSNA 550/13","sectionType":"part","heading":"AD/CESSNA 550/13","content":"## AD/CESSNA 550/13","sortOrder":1},{"sectionNumber":"Bleed Air Check Valve","sectionType":"part","heading":"Bleed Air Check Valve","content":"## Bleed Air Check Valve","sortOrder":2},{"sectionNumber":"12/2009","sectionType":"part","heading":"12/2009","content":"## 12/2009","sortOrder":3}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1237},"content_quality":"ok","complexity_score":1,"scope_assessment":{"changed":false,"description":"This instrument terminates the legal effect of an existing Airworthiness Directive without expanding, restricting, or otherwise modifying the scope of the original legislation. It is a pure revocation."},"complexity_factors":["Single operative provision consisting only of cancellation","No interpretation section or defined terms","No cross-references to other legislation or regulations","Factual background statement with no conditional or contingent provisions"],"plain_english_summary":"**What this does:** This document cancels an old aircraft safety rule (an Airworthiness Directive) that required owners of Cessna 550 business jets to replace faulty **bleed air check valves** (parts that prevent air pressure from flowing backwards in the engine system).\n\n**Who it affects:** Owners and operators of Cessna 550 (Citation II) series aircraft. In practice, this affects almost no one today, as the original rule required compliance by 1986—meaning all affected planes were modified decades ago.\n\n**Why it matters:** It formally removes a 23-year-old maintenance requirement that has become redundant. This is regulatory housekeeping—cleaning up obsolete rules so operators don't have to track requirements that no longer serve any safety purpose."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-550-13-bleed-air-check-valve-cancelled","history":"/api/acts/ad-cessna-550-13-bleed-air-check-valve-cancelled/history","analysis":"/api/acts/ad-cessna-550-13-bleed-air-check-valve-cancelled/analysis","conflicts":"/api/acts/ad-cessna-550-13-bleed-air-check-valve-cancelled/conflicts","importantCases":"/api/acts/ad-cessna-550-13-bleed-air-check-valve-cancelled/important-cases","documents":"/api/acts/ad-cessna-550-13-bleed-air-check-valve-cancelled/documents"}}