IREX/PIFR Students: CASR 91 MOS Changes
On 11 February 2025, the Civil Aviation Safety Authority announced significant amendments to the Part 91 Manual of Standards (MOS), which will take effect on 1 March 2025. This update introduces key changes affecting landing minima and the classification of military operating areas.
A Closer Look at the Changes
Updated Visibility Requirements for Landing Minima
One of the core changes in this update is the correction of visibility requirements in section 15.10 of CASR Part 91 MOS. The revisions are designed to:
- Align with Approach Procedure Classifications: Visibility corrections are now organised under Non-Precision Approach (NPA), Approach with Vertical Guidance (APV), and Precision Approach (PA) procedures.
- Differentiate Based on Approach Lighting Splay: The visibility requirements are grouped depending on whether the final approach track falls within the defined ‘visible approach lighting splay’—a term clearly outlined in the updated MOS.
- Match Design Specifications: The corrections are accurately related to the design standards for full, intermediate, basic, and nil approach lighting systems.
- Round Up for Failed Lighting Systems: For scenarios where the approach lighting system has failed or partially failed, the visibility requirement will be rounded up to the nearest 100 metres.
These detailed adjustments aim to remove ambiguity and enhance safety during critical landing phases.
Introduction of Military Operating Areas (MOAs)
Another significant amendment is the introduction of military operating areas (MOAs) in section 11.23 of the MOS. This addition highlights a closer integration between civil and military airspace operations, ensuring that airspace management remains comprehensive and up-to-date.
This has been in effect for a while now (in the AIP) and is now standardised in the MOS.
Read the Updated MOS
- Before 1 March 2025: Review the unofficial compilation of the Part 91 MOS to get a detailed understanding of the proposed changes.
- After 1 March 2025: Visit the Federal Register of Legislation to view the official compilation and amendment instrument.
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