{"id":"F2006B08379","name":"AD/CESSNA 400/95 - Pilots Instruments Air System","slug":"ad-cessna-400-95-pilots-instruments-air-system","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115805,"registerId":"commonwealth-F2006B08379-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 400/95 - Pilots Instruments Air System","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nCessna 400 Series Aeroplanes\n\nAD/CESSNA 400/95 Pilot’s Instruments Air System 11/88\n\nApplicability: Models 425 equipped with pneumatic gyro instruments in the left instrument panel and approved for IFR operations.\n\nRequirement: Action in accordance with CESSNA Service Bulletin CQB 88-9 and Service Kit SK425-41.\n\nCompliance: Not later than 31 March 1989.\n\nBackground: The existing instrument air pressure regulator by itself is not capable of operating at high overpressure conditions and may close and shut off airflow to the attitude and directional gyros. In the event an overpressure condition failure occurs, the additional regulator installed per this AD is designed to provide reduced air pressure at an acceptable value to the inlet of the existing regulator to assist it in operating normally.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":1536},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope as a targeted safety modification addressing a specific mechanical failure mode in a defined aircraft type. No evidence of scope creep or expansion beyond the original airworthiness concern."},"complexity_factors":["Single, clearly defined applicability limited to one aircraft model with specific equipment","One unambiguous compliance action referencing external technical standards (Service Bulletin)","Hard compliance deadline with no conditional extensions","No defined terms, cross-references to other legislation, or nested exceptions","Straightforward technical background explaining the safety risk in plain language"],"plain_english_summary":"This Airworthiness Directive requires owners/operators of Cessna 425s approved for IFR with pneumatic gyros in the left panel to install an additional air pressure regulator per Cessna SB CQB 88-9 using Service Kit SK425-41 (installation due by 31 March 1989). It prevents loss of attitude and directional gyros from regulator failure during overpressure—avoiding potentially fatal instrument loss in IMC."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-400-95-pilots-instruments-air-system","history":"/api/acts/ad-cessna-400-95-pilots-instruments-air-system/history","analysis":"/api/acts/ad-cessna-400-95-pilots-instruments-air-system/analysis","conflicts":"/api/acts/ad-cessna-400-95-pilots-instruments-air-system/conflicts","importantCases":"/api/acts/ad-cessna-400-95-pilots-instruments-air-system/important-cases","documents":"/api/acts/ad-cessna-400-95-pilots-instruments-air-system/documents"}}