{"id":"F2011L01582","name":"CASA 327/11 – Determination – lowest safe altitude","slug":"casa-327-11-determination-lowest-safe-altitude","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":125933,"registerId":"commonwealth-F2011L01582-current","compilationNumber":null,"startDate":"2026-04-03","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"CASA 327/11 – Determination – lowest safe altitude","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-description: Determination — lowest safe altitude\nmeta-generator: Aspose.Words for .NET 20.2\ntitle: CASA 327/11\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nInstrument number CASA 327/11\n\nI, gregory james hood, Executive Manager, Operations Division, a delegate of CASA, make this instrument under subregulation 178 (6) of the Civil Aviation Regulations 1988.\n\n[Signed Greg Hood]\n\nGreg Hood  Executive Manager  Operations Division\n\n25 July 2011\n\nDetermination — lowest safe altitude\n\n1 Duration\n\n This instrument:\n\n(a) commences on 1 August 2011; and\n\n(b) stops having effect at the end of 31 July 2014.\n\n2 Application\n\n  This instrument applies to CASA’s determination of a method of calculating the lowest safe altitude by Qantas Airways Limited, Aviation Reference Number 216147 (the operator).\n\n3 Determination\n\n  I determine that the operator may use either the Jeppesen Grid Minimum Off Route (MORA) method or the Digital Terrain method as a method of calculating the lowest safe en route altitude.\n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2100},"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This instrument maintains a narrow, specific scope limited to granting alternative compliance methods for a single airline operator. It does not expand beyond the standard regulatory function of approving specific calculation methodologies under the Civil Aviation Regulations."},"complexity_factors":["Only 3 operative sections covering duration, application, and the determination","Single defined entity ('the operator' referring specifically to Qantas Airways Limited)","No internal cross-references, exceptions, or conditional clauses","Straightforward binary choice between two permissible calculation methods"],"plain_english_summary":"This instrument authorises **Qantas Airways** to use alternative methods for calculating how high aircraft must fly to avoid terrain and obstacles when not following established flight paths.\n\nUnder aviation safety rules, airlines must ensure planes maintain a **lowest safe altitude**—the minimum height above ground level required for safety. While standard methods exist, this determination permits Qantas to calculate this altitude using either:\n\n*   **The Jeppesen Grid MORA method** (a commercial navigation system using grid-based minimum altitude data), or  \n*   **The Digital Terrain method** (using electronic elevation maps).\n\nThis approval applies exclusively to Qantas and allows the airline flexibility in navigation planning while ensuring terrain clearance standards are met."}},"importantCases":[],"_links":{"self":"/api/acts/casa-327-11-determination-lowest-safe-altitude","history":"/api/acts/casa-327-11-determination-lowest-safe-altitude/history","analysis":"/api/acts/casa-327-11-determination-lowest-safe-altitude/analysis","conflicts":"/api/acts/casa-327-11-determination-lowest-safe-altitude/conflicts","importantCases":"/api/acts/casa-327-11-determination-lowest-safe-altitude/important-cases","documents":"/api/acts/casa-327-11-determination-lowest-safe-altitude/documents"}}