{"id":"F2006B05977","name":"AD/PA-42/11 - Hydraulic Hose","slug":"ad-pa-42-11-hydraulic-hose","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":136175,"registerId":"commonwealth-F2006B05977-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/PA-42/11 - Hydraulic Hose","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)  Piper PA-42 (Cheyenne III) Series Aeroplanes\n\n \n\nAD/PA-42/11 Hydraulic Hose 6/86 DM\n\nApplicability: All model PA-42 Cheyenne III with S/Nos 42-7800001, 42-7800002, 42-7801003, 42-7801004 and 42-8001001 to 42-8001106.\n\n \n\nAll model PA-42 Cheyenne IIIA with S/Nos 42-8301001, 42-8301002, 42-5501003 to 42-5501023, 42-5501025.\n\n \n\nRequirement: Action in accordance with Piper Service Bulletin No. 822. Compliance:  Within 25 hours time in service after 19 May 1986.\n\nBackground: A group of hydraulic hoses were manufactured using material that does not meet the pressure requirements for operation in the aircraft hydraulic system.\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\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"The AD’s scope remains limited to the specific PA-42 Cheyenne III and IIIA airframes listed by serial number and requires compliance with the manufacturer’s Service Bulletin. There is no indication in the text that the applicability or required actions were broadened beyond that original technical and serial‑numbered focus (Applicability; Requirement)."},"complexity_factors":["Narrow applicability defined by a discrete list of serial numbers (Applicability)","Mandatory compliance tied to an external technical document (Piper Service Bulletin No. 822) rather than prescribing detailed steps in the AD itself (Requirement)","Short mandatory compliance window (25 hours TIS after 19 May 1986) that affects maintenance scheduling (Compliance)","Safety‑critical technical issue (hydraulic hose material not meeting pressure requirements) but limited to specific production batch (Background)","Regulatory reliance on manufacturer‑issued remedial action with enforcement by the civil aviation authority (title/heading; Requirement)"],"plain_english_summary":"This AD mandates that owners/operators of the specified Piper PA‑42 (Cheyenne III/IIIA) serial‑numbered aeroplanes comply with Piper Service Bulletin No. 822 to inspect/rectify suspect hydraulic hoses within 25 hours TIS after 19 May 1986. It affects the listed aircraft, the maintenance organisations that must perform the work, and the regulator; it’s a short, mandatory action to remove non‑conforming hoses that may not meet hydraulic pressure requirements and thus mitigate safety risk."},"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a discrete, targeted safety directive addressing a specific manufacturing defect in specific aircraft. It has not expanded beyond its original purpose of mandating hose replacement for affected Piper PA-42 aircraft."},"complexity_factors":["Very short document (approximately 200 words)","Only 2 defined applicability groups (specific aircraft models and serial numbers)","Single requirement referencing an external technical document (Piper Service Bulletin No. 822)","Simple compliance deadline (25 hours time in service after a fixed date)","No nested conditions, exceptions, or cross-references to other legislation","Straightforward factual background with no legal interpretation required"],"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) under the Civil Aviation Regulations 1998.\n\n**What it does:** It requires owners and operators of specific Piper PA-42 Cheyenne III and IIIA aircraft to replace or inspect certain hydraulic hoses. The hoses were manufactured with substandard material that cannot handle the pressure demands of the aircraft's hydraulic system, creating a safety risk.\n\n**Who must comply:**\n- Owners/operators of PA-42 Cheyenne III aircraft with specific serial numbers (42-7800001, 42-7800002, 42-7801003, 42-7801004, and 42-8001001 through 42-8001106)\n- Owners/operators of PA-42 Cheyenne IIIA aircraft with specific serial numbers (42-8301001, 42-8301002, and 42-5501003 through 42-5501023, plus 42-5501025)\n\n**What action is required:** Follow the instructions in **Piper Service Bulletin No. 822** — a technical document from the manufacturer detailing exactly what needs to be done to fix the problem.\n\n**When it must be done:** Within 25 hours of flight time after 19 May 1986.\n\n**Why it matters:** Hydraulic system failures in flight can lead to loss of control of critical systems like landing gear, flaps, or brakes. This directive prevents potential accidents by ensuring defective hoses are replaced before they fail under pressure."}},"importantCases":[],"_links":{"self":"/api/acts/ad-pa-42-11-hydraulic-hose","history":"/api/acts/ad-pa-42-11-hydraulic-hose/history","analysis":"/api/acts/ad-pa-42-11-hydraulic-hose/analysis","conflicts":"/api/acts/ad-pa-42-11-hydraulic-hose/conflicts","importantCases":"/api/acts/ad-pa-42-11-hydraulic-hose/important-cases","documents":"/api/acts/ad-pa-42-11-hydraulic-hose/documents"}}