On 4 August 2025, the International Civil Aviation Organization published new Standards and Recommended Practices (SARPs) and changes to Part 6 of the Airport Services Manual (Doc 9137). These SARPS and changes relate to the protection of low-level airspace in the immediate vicinity of aerodromes.
The specifications of imaginary surfaces used to control obstacles will change for the first time in over forty years.
The new ICAO SARPs will change the way obstacles are assessed, controlled or restricted. The new ICAO object limitation surface (OLS) SARPs focus on providing protection of the aircraft using the runway from obstacles. This ensures the protection of aircraft using instrument flight procedures or undertaking visual circuit patterns.
The new OLS intends to focus on the areas and airspace needed to ensure the safe navigation of aircraft.
The new ICAO SARPs include:
- the introduction of the new aeroplane design group (ADG), which separates OLS from the existing aerodrome infrastructure aerodrome reference code (ARC)
- the removal of some existing surfaces and introduction of new surfaces, split into obstacle free surfaces (OFS) and obstacle evaluation surfaces (OES)
- the ability to adjust surfaces to suit the specific needs of the aerodrome and its operating environment
- the introduction of new aeronautical assessment methodologies and safety analysis for new obstacles.
The Technical Working Group will provide guidance and advice to CASA over 4 stages on key deliverables for this significant and historic change. The initial TWG will review stage 1 as outlined below.
We will determine additional work on future stages through updated tasking instructions, the introduction of subgroups, and updated membership as required.
Stage 1: Consider policy options, determine the most effective and acceptable approaches, and deliver a preferred policy in consideration of the Australian aviation safety framework.
Latest update
Membership
The initial membership listing below is subject to review and refresh as required:
- Kenneth Allcott
- Sarah Capenerhurst
- Jack Corkill
- Grace Daniel – Observer
- Brian Greeves
- Gary Lee
- Andrew Mihu
- Brendon Montgomery – Observer
- Obrad Puskarica
- Sanjiv Sathiah
- Karen Titmuss
- Rob Walker.
Tasking instructions
4 Nov 2025