News & Discussion: General CBD Development

[[Shuz]]

CASA limit at Realm was 186m, yeah? It's possible the conical slope of the radars would permit 230m at the 123m Flinders site, as 300m is permitted on corner of South & Pulteney.

[Algernon]

CASA limit at Realm was 186m, yeah? It's possible the conical slope of the radars would permit 230m at the 123m Flinders site, as 300m is permitted on corner of South & Pulteney.

Honestly does anybody inside or outside of the aerospace industries even have a consistent view or understanding of how this all works? I find it amazing that Essendon airport on the other side of Melbourne keeps everything to around 300m in their CBD, and yet in Adelaide apparently you can just walk a few blocks and get a 300m height limit for the airport which is pissing distance.

[Spurdo]

I'm fairly sure that the plans for 260 Flinders indicated that the PANS-OPS ceiling for the area around Flinders Street to Rymill Park was around 250 metres.

[slenderman]

Not certain, but I'm pretty sure it goes like this:

- You can build higher than Obstacle Limitation Surface (OLS) if approval is given. There's a map which shows OLS in the CBD that's available publically on the internet.

- You can only temporarily break the PANS-OPS limits (in the case of construction cranes that are higher than the building will be), but a permanent structure can't break these limits unless they appeal to have the limits raised for the area above the building. PANS-OPS isn't available for Adelaide except for little tidbits like that in the Realm Adelaide report. Not entirely sure why it isn't available, nor do I know where this 300m figure for South Tce/Pulteney Street came from.

Don't know why Essendon airport (seemingly) affects Melbourne more than Adelaide. Someone with more knowledge in this field can probably give a better answer.

[slenderman]

I'm fairly sure that the plans for 260 Flinders indicated that the PANS-OPS ceiling for the area around Flinders Street to Rymill Park was around 250 metres.

If that's the case, and that 250m figure is in AHD, then surely PANS-OPS for the 123 Flinders Street site wouldn't allow for anything much bigger than 200m above ground level on that site.

[[Shuz]]

300m came from the CASA height map of Adelaide thats pubicly available.

[monotonehell]

Back in 2008, members of this forum did an investigation into PANS-OPS and its ilk and produced this submission which we've sent to a few places and public consultations...

http://sensational-adelaide.com/forum/v ... 130#p59130

You can read how the height restrictions work in there.

(tl;dr: Not all regulations are a set surface you can view on a map. A developer has to ask for a height datum to be researched and they then get a response.)

[slenderman]

Back in 2008, members of this forum did an investigation into PANS-OPS and its ilk and produced this submission which we've sent to a few places and public consultations...

http://sensational-adelaide.com/forum/v ... 130#p59130

You can read how the height restrictions work in there.

(tl;dr: Not all regulations are a set surface you can view on a map. A developer has to ask for a height datum to be researched and they then get a response.)

Bleurgh, I'm getting confused.

I've done a bit of digging, trying to find a PANS-OPS value for the 123 Flinders Street site, looking at nearby sites across the city and their PANS-OPS values. That led me to the 84m proposal at 124 Wakefield Street, where I found this document containing a PANS-OPS map for the Adelaide CBD (see Figure 4, Page 05).

http://www.dac.sa.gov.au/__data/assets/ ... d_St_2.pdf

It accurately puts One Adelaide's PANS-OPS surface at just over 250m and Realm Adelaide's PANS-OPS surface at 210m. However, it appears to conflict with the 300m figure Shuz gave, which lies between the 240m contour and another contour of a height I can't find.

123 Flinders lies between the 240 and 250m contours, so I believe that means that the tallest building allowed on that site would be around or perhaps a little bit under 200m above ground. I can't seem to find any location in the CBD that would allow for a building of 230m above ground.

I flipped through that thread and the pdf submission at your link, but didn't find much more detail on what you've said that I bolded (sorry if it's just me being lazy), so I'm getting confused. Is this map consistent with what you're saying?

[Nort]

CASA limit at Realm was 186m, yeah? It's possible the conical slope of the radars would permit 230m at the 123m Flinders site, as 300m is permitted on corner of South & Pulteney.

Honestly does anybody inside or outside of the aerospace industries even have a consistent view or understanding of how this all works? I find it amazing that Essendon airport on the other side of Melbourne keeps everything to around 300m in their CBD, and yet in Adelaide apparently you can just walk a few blocks and get a 300m height limit for the airport which is pissing distance.

I would suggest it's due to the Adelaide hills.

In flatter areas, you want to have more flexibility to give aircraft different inbound and outbound routes in cases of emergency. Due to the Adelaide Hills however there are already obstacles to consider and you can more safely allow a taller structure since that path can't be used.

[monotonehell]

(tl;dr: Not all regulations are a set surface you can view on a map. A developer has to ask for a height datum to be researched and they then get a response.)

Bleurgh, I'm getting confused.
I flipped through that thread and the pdf submission at your link, but didn't find much more detail on what you've said that I bolded (sorry if it's just me being lazy), so I'm getting confused. Is this map consistent with what you're saying?

There's no such thing as a prepared map with a surface on it that describes what the PANS-OPS height will be for anywhere.

The developer has to submit a design, then the powers that be do their complex calculations, work out what the implications on radar and other navigation systems would be, make chicken and goat sacrifices, eyeball models with their tongues stuck out of the corners of their mouths at appropriate angles, etc, etc and after much work they come up with a yes or no result for that one design.

We think (the information was not exactly free flowing at the time) that calculating PANS-OPS heights has to do with a complex amount of interactions of all the differing factors. It's not just an altitude that planes can fly over (That's OLS?)

[slenderman]

(tl;dr: Not all regulations are a set surface you can view on a map. A developer has to ask for a height datum to be researched and they then get a response.)

Bleurgh, I'm getting confused.
I flipped through that thread and the pdf submission at your link, but didn't find much more detail on what you've said that I bolded (sorry if it's just me being lazy), so I'm getting confused. Is this map consistent with what you're saying?

There's no such thing as a prepared map with a surface on it that describes what the PANS-OPS height will be for anywhere.

The developer has to submit a design, then the powers that be do their complex calculations, work out what the implications on radar and other navigation systems would be, make chicken and goat sacrifices, eyeball models with their tongues stuck out of the corners of their mouths at appropriate angles, etc, etc and after much work they come up with a yes or no result for that one design.

We think (the information was not exactly free flowing at the time) that calculating PANS-OPS heights has to do with a complex amount of interactions of all the differing factors. It's not just an altitude that planes can fly over (That's OLS?)

I think I get what you're saying, but I'm still a bit confused.

Here's the PANS-OPS map from that link I supplied (I suggest downloading that PDF if you want to see the picture/numbers more clearly):

PANS-OPS.PNG (379.39 KiB) Viewed 3274 times

Is this map something that whoever created the document has conjured up from nowhere themselves (doubtful, as it checks out with other PANS-OPS values that we know from other developments), or is it something that the powers that be have created which acts as more of an "in the ballpark" guideline, but when a particular development is submitted that is above OLS, they still crunch their complex numbers to give an exact allowable PANS-OPS height for that development and then accordingly give the design a yes/no?

[[Shuz]]

That's the first time I've seen a detailed PANSOPS map for Adelaide. One thing I've deduced, is that its not possible for the building to be 230m tall at the 123 Flinders location. The PANSOPS is 240m, and Adelaide CBD is roughly 40m above sea level, so at best, that site could accommodate a 200m / 50 level tower.

[monotonehell]

Confusion is understandable. There seems to be a lot of contradicting evidence, and a near stonewall from the authorities who do the approving. This is why we made the investigation and submission back in 2008.

That diagram looks more like the OLS map for Adelaide Airport. Although there's some extra frilly bits I've not seen before. It could be a creation from other data by the developer because they "needed something in the document".

The only time we've seen a diagram of the PANS-OPS surface is where it's, again, been required by some bureaucracy and the designers of the document have created one. Even though the regulations require such a map to be made available to the public.

After extensive requests by Wayno back in 2008 we came to the conclusion that no such map was available, other than the rough one in Adelaide Airport's development plan. (Which is reproduced in the S-A submission.)

The weird thing is that the regulations also state that penetrating the PANS-OPS ceiling is prohibited, and yet we have several applications which do so and have been approved.

FYI OLS v PANS-OPS:

International standards have been adopted which define two sets of invisible surfaces above the ground around an airport. The airspace above these surfaces forms the airport's protected airspace. These two surfaces are the:

Obstacle Limitation Surface (OLS); and
Procedures for Air Navigational Services—Aircraft Operations (PANS-OPS) surface

The OLS is generally the lowest surface and is designed to provide protection for aircraft flying into or out of the airport when the pilot is flying by sight. The PANS-OPS surface is generally above the OLS and is designed to safeguard an aircraft from collision with obstacles when the aircraft's flight may be guided solely by instruments, in conditions of poor visibility.

https://infrastructure.gov.au/aviation/ ... eased.aspx

[ChillyPhilly]

Not certain, but I'm pretty sure it goes like this:

- You can build higher than Obstacle Limitation Surface (OLS) if approval is given. There's a map which shows OLS in the CBD that's available publically on the internet.

- You can only temporarily break the PANS-OPS limits (in the case of construction cranes that are higher than the building will be), but a permanent structure can't break these limits unless they appeal to have the limits raised for the area above the building. PANS-OPS isn't available for Adelaide except for little tidbits like that in the Realm Adelaide report. Not entirely sure why it isn't available, nor do I know where this 300m figure for South Tce/Pulteney Street came from.

Don't know why Essendon airport (seemingly) affects Melbourne more than Adelaide. Someone with more knowledge in this field can probably give a better answer.

I just did a bit of digging and found this for Essendon Airport. It explains it perfectly, with PANS-OPS heights illustrated and explained as well. Perfect:

https://urban.melbourne/policy/2013/11/ ... -explained

In addition, visit these links:

http://www.essendonairport.com.au/plann ... protection
http://www.essendonairport.com.au/uploa ... ooklet.pdf

[Ben]

A fair bit of information here for those that wish to read it.

http://www.dac.sa.gov.au/__data/assets/ ... rket_3.pdf

http://www.adelaideairport.com.au/corpo ... approvals/