{"id":"F2006B08157","name":"AD/CESSNA 310/30 - Alternate Air System - Modification","slug":"ad-cessna-310-30-alternate-air-system-modification","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":115325,"registerId":"commonwealth-F2006B08157-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/CESSNA 310/30 - Alternate Air System - Modification","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 310 Series Aeroplanes\n\n \n\nAD/CESSNA 310/30 Alternate Air System - Modification 7/73\n\nApplicability: Model 310 with S/Nos. 310N0001 to 310Q0520 but excluding model T310. Document:               Cessna SL No. ME72-21.\n\nCompliance: Within 100 hours time in service after 31 July 1973.\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\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, single-issue airworthiness directive from 1973. It has not expanded beyond its original purpose of mandating a specific safety modification to a defined subset of Cessna 310 aircraft. The scope remains precisely as originally intended."},"complexity_factors":["Extremely short document — only 8 substantive lines","No defined terms section — all terms are standard aviation terminology","No cross-references to other legislation beyond the enabling regulation (Civil Aviation Regulations 1998, Part 39)","Simple conditional logic: applicability is a straightforward serial number range with one exclusion","Single compliance requirement with clear deadline and reference document","No exceptions, nested conditions, or discretionary provisions"],"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 requires:** Owners and operators of specific **Cessna 310 series aircraft** must modify the **alternate air system** (a backup air intake for the engines, used if the main intake gets blocked by ice or debris).\n\n**Who it affects:** \n- **Specific aircraft:** Cessna Model 310 with serial numbers from 310N0001 to 310Q0520\n- **Exclusion:** Does NOT apply to the T310 model (a turbocharged variant)\n\n**What must be done:** The modification must be carried out following **Cessna Service Letter No. ME72-21** (the manufacturer's official instructions for this fix).\n\n**When it must be done:** Within **100 hours of flight time** after **31 July 1973**.\n\n**Why it matters:** Airworthiness Directives are legally binding safety requirements. If you don't comply, you cannot legally fly the aircraft. This particular AD addresses a potential safety issue with the alternate air system — likely a design flaw that could affect engine performance or safety in certain conditions. Non-compliance means the aircraft is not considered airworthy."},"flash_summary":{"complexity_score":2,"scope_assessment":{"changed":false,"description":"The directive as published is narrowly targeted and self-contained in scope: it prescribes a modification for a specific model and serial-number range, references a Cessna Service Letter for the technical method, and sets a single compliance window (Applicability; Document; Compliance). The instrument does not indicate an expansion or contraction of that scope compared with its expressed terms."},"complexity_factors":["Narrow technical scope limited to a single modification (Alternate Air System) reduces legal complexity.","Applicability limited to a specific serial-number range and excludes one submodel, requiring accurate record checks (Applicability).","Compliance measured in flight hours with a fixed post-date window creates a simple but time-tracked deadline (Compliance).","Reference to an external technical document (Cessna SL ME72-21) concentrates technical detail outside the AD, adding an operational dependency (Document).","The AD text does not specify enforcement mechanics, certification of work, or acceptable maintenance standards, which leaves operational detail to implementers and referenced documents."],"plain_english_summary":"This AD requires owners/operators of Cessna Model 310 aircraft (S/N 310N0001–310Q0520, excluding T310) to have the alternate air system modified per Cessna Service Letter ME72-21. The work must be done within 100 hours time‑in‑service after 31 July 1973; owners/operators are responsible for arranging and funding the modification to remain compliant."}},"importantCases":[],"_links":{"self":"/api/acts/ad-cessna-310-30-alternate-air-system-modification","history":"/api/acts/ad-cessna-310-30-alternate-air-system-modification/history","analysis":"/api/acts/ad-cessna-310-30-alternate-air-system-modification/analysis","conflicts":"/api/acts/ad-cessna-310-30-alternate-air-system-modification/conflicts","importantCases":"/api/acts/ad-cessna-310-30-alternate-air-system-modification/important-cases","documents":"/api/acts/ad-cessna-310-30-alternate-air-system-modification/documents"}}