It seems like NAS has come back again, or maybe it never really left us.
In accordance with CASA policy the ultimate model should emulate identified best practice in the United States National Airspace System design
There has been spirited discussion about this in DG&P General Aviation & Questions forum over the last few months in the thread Class D Zones for Broome & Karratha. The latest move affects airline and RPT operations, which is why I'm raising it here.
What has emerged from the woodwork is the new NAS vision for control zones at regional airports. The first cabs off the rank are Karratha and Broome. Looking at the Airspace Change Proposal (thanks Capn Bloggs for the link), the airspace redesign elements associated with the upcoming towers there are:
- smaller than the normal Australian control zone. With a D boundary @ A025, that'll make the zone about a 8NM radius. It is a lot smaller than the A045 and 22NM radius found at regional control towers elsewhere in Australia.
- E over D airspace
- no surveillance radar
Reading back through the GA thread, there is:
- no cost saving with the small control zone
- a big backward step to unalerted see-and-avoid as the only line of defence in the zone between the current 30nm radius CAGR/S at Broome and the proposed 8nm radius zone for the control tower at Broome.
This is a DOUBLE Airspace Change Proposal – the "new" NAS airspace has been hidden (or should that be buried?) in the Airspace Change Proposal to put towers at Karratha and Broome. The tower issue was generally accepted by all. But this NAS Airspace Change Proposal is something else again. There is no safety case for this, no modelling, no justification, and no cost saving. But a big step backwards as airline and RPT mix it up with the lowest common denominator of unalerted see-and-avoid GA.
In the absense of a safety case, what I could find was in the minutes of the local GA industry consultation at Broome last month which have just come out:
asked for each chief pilot present to advise which option for the size of control area they considered safer. While the Chief Pilots raised other issues, they, when asked in turn, advised that a control area of 8nm and 2500’ at Broome was inadequate, and was less safe than 22nm and 4500’ option for class D. All stated that the CASA model would not work at Broome due to communication traffic, it was not safe, and would cause delays.
CASA have asked for comments, so here is everyone's chance:
The OAR is sympathetic to this view, but input from the wider aviation community is sought before the final airspace structure at these locations is decided upon by CASA. Stakeholders are therefore requested to provide feedback on this issue
The details and email address are
here at CASA and closing date is 31st March 2010.
This has broad implications for airline and RPT operations in regional airspace. I'm posting this short summary in DG&P Reporting Points because the sneaky way that these changes are being tried on will have kept them from view of many.