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-   -   NAS Frequency Boundaries continued. (https://www.pprune.org/australia-new-zealand-pacific/108092-nas-frequency-boundaries-continued.html)

snarek 10th Nov 2003 04:51

Probably the same reasons I didn't resign but ran for election. :)

You could rejoin, then your opinions would be more powerful, especially if (as i gather) you are a tin driver as well as a tin pusher.


OverRun 10th Nov 2003 09:33

If I can get a word in edgeways between the AOPA sniping . . . .

The Steamboat Springs being referred to is not the little airport at the town, but is Steamboat Airport (Yampa Valley at Hayden). Identifier HDN. About 10,000 feet of asphalt runway and in a typical ski season weekend day, it does take 146, 737-300, 737-800, A320 and 757 from all the big name airlines. It takes annual movements 4226 RPT, 304 air taxi, 3898 local GA, 7924 itinerant GA. They run a 24hr UNICOM, without FSS or tower. And there is good radar coverage from Denver of the airspace around the airport.

Icarus2001 10th Nov 2003 10:20

I thought that it was quite interesting to see Open Mic browsing the forums this morning but choosing not to engage with the great unwashed or perhaps attempt to set straight some incorrect perceptions about the reforms and enhancements to our obviously ailing Air Traffic system.

snarek 10th Nov 2003 11:22

just perhaps
Perhaps Open Mic would engange with you guys if he though it worthwhile.

These topics contain about 5% useful info and opinion cleverly camoflaged under piles of useless sh!t.

For instance, I am immediately put off by

If I can get a word in edgeways between the AOPA sniping . . . .
So i don't read on. But if the info after it was important I'd be later criticised for not paying attention.

Now, I PERSONALLY have some doubts about NAS. But I also believe we are going to get NAS, so i put my 2c worth in wherever possible.

I also firmly believe consultation is about getting all the facts and opinions, sifting them and making a decision. It ain't about satisfying every whinger and loon on the planet. So don't be surprised when the 4 or 5 antagonists on here get ignored. The trick is to be a player, not a whinger.

Besides, a regulator's job is to make everyone equally unhappy!!!

So, you can put on your best rusty armour and go tilt at the big windmill, or you can point our problems with NAS and solutions that are acceptable to the majority.

That's how you get change......


SM4 Pirate 10th Nov 2003 11:39


but is Steamboat Airport (Yampa Valley at Hayden)
very inetersting, we would know that how? All references were to Steamboat Springs...

Me thinks Open Mic might have an alias; or has your ear old son.

Bottle of Rum

Aus ATC 10th Nov 2003 18:19

Back to the topic!
As a VFR pilot you can elect to monitor the ATC Frequency (the fluffy clouds on ERC - by the way who outside of ATC knows where half these locations are anyway!).

Having decided to monitor the closest frequency to your track (because you are cruising at a highish level in Class E airspace), it might be reasonable to assume that IFR traffic in proximity will also be on that frequency.

Sorry - your assumption is flawed (some of the time anyway). ATC sectors still exist with fairly rigid frequency boundaries in both the vertical and lateral dimensions. IFR traffic could well be maintaining primary listening watch on a frequency which is not on your chart.

Keep a good look out!


twodogsflying 10th Nov 2003 19:07

Elevation 6602 feet
Approach procedures:

Departure procedures:
IFR Take off minimums and departure procedures

Due to the proximity of the Hayden Airport to the Steamboat Springs (SBS) and Craig (CAG) Airports, certain IFR procedures overlap. Delays may be encountered because of this situation.



Weather Data Sources: AWOS-3: 119.27 (970) 276-3690

For IFR clearances, contact Denver Center 134.5 BEFORE TAXI.

Denver AFSS serves the airport and can be contacted on the Hayden RCO; 122.25. For weather briefing, call 1-800-992-7433 (1-800-WX-BRIEF).

RADAR coverage exists generally 10,000' MSL and above.

If you depart VFR and call airborne for your IFR you must remember your priority has moved down the list and will be accommodated when all other previous priorities have been accomplished.

Airport Operational Statistics
Aircraft based on the field: 7
Single engine airplanes: 4
Multi engine airplanes: 2
Gliders airplanes: 1

Aircraft operations: avg 36/day
53% transient general aviation
17% commuters
16% local general aviation
11% air carriers
3% air taxi
<1% military


The Above are from 2 web sites.

The interesting thing is RADAR starts at 3198 feet AGL. IFR must get a clearance before TAXI and there are 36 movements a day (Average) with AIR Carriers at less than 4 a day!

I cannot think of any airport in Australia anything like this place!

I wonder how SMITHS, M, D and B sleep at night?

Aussie Andy 10th Nov 2003 22:21

Hi guys, here is my current penneth worth - from afar:

Regarding Class E Airspace

I see everyone is still pretty upset at the prospect of the introduction of Class E airspace in which IFR may be separated from IFR, but VFR must "see and avoid" both IFR and other VFR traffic, and that VFR traffic may well not be on the same frequency as the IFR traffic.

As upsetting and "unsafe" is this must seem to you guys, the fact still remains that this system is in widespread use in the US and elsewhere, and there appears to be no evidence that it is less safe than the current Australian system (in fact I believe the opposite has been suggested earlier in the first thread on this subject).

So isn't the problem that you will have to find some empirical evidence that shows the current system is "more safe" if you want to object to the proposed changes (end-state) on safety grounds? Otherwise you will continue to have people who fly in the US, France and other places that make extensive use of Class E, arguing that it doesn't seem to be the cause of too many problems.

For a discussion of what happens in French class E near Lille, where VFR are not even answered, and IFR are provided service on a frequency on which VFR are not even welcome, see the thread in the ATC forum Has Lille given up completely, especially the bit at the end... So even in this environment, with apparently poor / confused co-ordination across some FIR boundaries, under-staffed ATC services and with greater traffic densities that generally experienced in Australia, its still not seen to be the cause of a higher risk outcome statistically AFAIK. I'm not arguing that this illustrates that Class E is a better system (that's a separate argument covered elsewhere), but if you are defending the "no change" position, I think you need to somehow deal with the point I have raised.

Regarding Transition and Education

The thing I can't understand from this distance is the apparent haste with which the changes appear to be being brought in. Do I understand correctly that the first phase of the changes take place at the end of this month, yet you are only now receiving educational materials? This strikes me as inherently unsafe and I think introduces "transition risk" independent of the merits (or otherwise!?) of the proposed end-state! What's the rush? What is the case against a slower transition?

Best to all,

Andy :ok:

Four Seven Eleven 11th Nov 2003 05:22

Aussie Andy

On your two points:

Class E and relative safety

Whilst I am unable to provide statistics on the relative safety of Cass C vs E airspace, the different procedures applicable in each do offer some empirical eveidence of the differing philosophy and safety objectives in each.

IFR are separated from IFR in both
Pilots are responsible for ‘see and avoid’ in both.

In Class C, IFR are separated from all aircraft. In E, only from other IFR. (Mike Smith’s contrary evidence to to the Australian Senate notwithstanding)
In Class E, ‘see and avoid’ is the primary means of collision avoidance. In Class C it is a ‘fall back’ only.

The primary reason, as I see it, why Class C is ‘safer’ (a relative term – as opposed to safe/not safe), is that Class C involves many more tiers of safety. In E, it is all reduced to one thing.

Transition and Education

On the point of ‘apparent haste’ - when is the next Federal election due?

Chief galah 11th Nov 2003 05:32

Aussie Andy
After reading your Lille link, I am even more convinced that our current system is simpler, more efficient, more user friendly and safer than what we are about to get, or what is in practise in your area. It appears Lille has it's own radar, so I can't image what the problem is.

The multilayered swiss cheese of 2b in respect of class E over class D, relies on

1. Transponders
2. "Appropriate frequencies"

both of which are weak links.

Peel these two fetid layers away, and we're left with a lot more air than cheese.


Aussie Andy 11th Nov 2003 06:17

Four Seven Eleven - well I don't think your post addresses the problem: your existing Class C does not cover anything like the areas that Class E is proposed for, so its not the right comparison.

Chief galah - but that's my point: there are still no reported / apparent / statistically significant safety problems EVEN with the crock of a situation such as is currently the case around Lille... which makes it sound like you guys are worrying too much.

Surely the point is that change is always difficult to swallow, and to manage. I think the issues here are primarily:
  • Promotion - in that they may have failed to persuade many constituents of the advantages of the new system over the old;
  • Education - in that people need time to properly understand, come to terms with and to digest the proposed changes, which should probably be inculcated via flight training organisations etc.; and
  • Change Management - in that the rollout of the changes should perhaps take palce in a less hasty manner. (And if what 4-7-11 suggests re- the influence of Federal election timing is to blame, then shame, shame, shame!).
Still, to my mind none of these issues indicates that the NAS will be "less safe" than your current arrangements, and I am yet to see any evidence to the contrary.

Cheers, and good night (its bed time in England!)

Andy :8

Four Seven Eleven 11th Nov 2003 09:07


To amplify my point:

Replacing vast tracts of Class G with Class E will lead to an increase in safety (particularly when/if G loses DTI service.)

Replacing Class C with E, particularly those bits of C which capture RPT jet traffic, will lead to a reduction in safety - primarilly affecting those who pay for the system.

I am at a loss as to what economic or other benefit will be achieved by exposing a B747 on descent into Sydney, or a B717 climbing out of Hobart, to the possibility of unknown, non-communication traffic, where a full separation service currently exists.

I can honestly not remember ever having knocked back a clearance to a VFR aircraft. So the idea that this will introduce some new level of freedom for VFR users is difficult for me to conceive. What the new system (E relacing C) does is to remove a significant safety defence.

The workload for the controller will increase as they are now required to separate the IFRs, while maintaining a continuous scan for the unidentified aircraft which may just be at the 'wrong' level. This involves sifting through the clutter of all the low-level VFR in class G below. It also involves being ready for any avoiding action the IFR aircraft may have to take, possibly in contravention of its clearance.


Lodown 11th Nov 2003 10:19

4711, doesn't TAAATS provide a level of protection by alerting controllers to conflicting traffic in conjunction with transponder-equipped aircraft and SSR? Obviously you wouldn't want to use this as a last line of defense, but this is something, like TCAS and GPS that we didn't have some years ago. There has also been the comment that we don't want to use TCAS as a last line of defense either, but these are all technological advances that we didn't have when the current airspace system was devised. How many 'last line(s) of defense' do we need? What was the 'last line of defense' 30 years ago? Whatever it was, I know I'd put my trust in modern technology over the system we had then. Taken in isolation, each one of these technologies would not be trusted as a 'last line of defense' but when the entire system is considered, then I don't have a problem with this aspect of NAS.

I am still in two minds about NAS, but surely if the technology allows us to advance and make the airspace more user friendly for all while raising capacity and at the same time without impinging on the operations of the big boys, then I am all for it.

Chief galah 11th Nov 2003 10:24


Believe me, I'm not worried too much. I just don't want a reasonable system to go down the tubes.

Re. statistical evidence about the safety of a system - it is only as good as the reporting.

Nobody has bothered to ask how much of our time is spent on transponder problems. It is significant, the time that is. The only way we know an aircraft is about with a transponder problem is by having primary radar backup. I'm sure the good people of the VFR fraternity in Tasmania don't particularly care about transponders or their serviceablility. They've flown forever there WITHOUT RADAR. No-one will ever know if the transponder's working, because it will never have been checked within the radar system!!!

And that won't change.

What they do know up until now they've received a pretty good service from the pros in Launy and Hobart towers.

Same applies at Albury, Alice Springs ( both non-radar) and all of the other D towers who may have limited SSR coverage only.


Adamastor 11th Nov 2003 10:43

Don't know if it qualifies as evidence in your book Aussie Andy, but when CASA were sent the Design Safety Case for NAS 2b - yes, I realise that it is 2b alone, but that's all we have to work on at the moment, as the safety cases for future stages are yet to be written (how the hell you can get away with that little gem I'll never know!) - their response, in part, was:

CASA has reviewed the Design Safety Case (DSC) dated 1st September 2003 and makes the following comments:
2. The detailed evaluation of the presented DSC evidences that the Stage 2b implementation will bring about an increase in risk beyond that which exists in Australia today, but CASA is unable to determine the degree of this additional risk from the material supplied in the DSC.
The fact that the regulators feel that the upcoming stage represents a reduction in safety raises a lot of people's hackles, including my own.

Neddy 11th Nov 2003 11:29

A child, however, who had no important job and could only see things as his eyes showed them to him, went up to the carriage.
"The Emperor is naked," he said.
"Fool!" his father reprimanded, running after him. "Don't talk nonsense!" He grabbed his child and took him away. But the boy's remark, which had been heard by the bystanders, was repeated over and over again until everyone cried:
"The boy is right! The Emperor is naked! It's true!"
The Emperor realized that the people were right but could not admit to that. He though it better to continue the procession under the illusion that anyone who couldn't see his clothes was either stupid or incompetent. And he stood stiffly on his carriage, while behind him a page held his imaginary mantle.

Just got to figure out which naked git is The Emperor!

AirNoServicesAustralia 11th Nov 2003 11:30

Lodown, you have been mislead if you think TAAATS has anything like TCAS, it has a very basic STCA(short term conflict alert) and it is (well was when I left Oz 12 months ago) renowned for being inconsistent at best.

Brian H, felt I made a personal attack on him, which I feel I didn't. I think that I stated a fact. That being that the VFR pilots like NAS because it allows them (supposedly) to go where they want without paying and without talking. That is fine, I understand from the VFR point of view that that would be seen as a positive.

My question that is still to be answered is:

1. Their will be an increase in workload to the ATC's(scanning their screen constantly) and to the RPT's (scanning their windscreen constantly). Their will be more controllers not less hence,

2. There will be no financial savings.

3. There will be a reduction in safety in the areas where Class C has become Class E. Whether this is an acceptable risk is irrelevant. hence,

4. Why change to a system where safety is reduced for no financial savings, and increased workload for most aviation proffessionals?

And finally the cherry on top of all this is the new charts and the ambiguity and difficulty in locating ATC frequencys. How is this a good thing, please answer that while you're at it.

I do not work in Australia at the moment, and will not be for some time to come. So please don't roll out the old chestnut of me trying to save my cushy little job.

SM4 Pirate 11th Nov 2003 12:33


4711, doesn't TAAATS provide a level of protection by alerting controllers to conflicting traffic in conjunction with transponder-equipped aircraft and SSR? ... Taken in isolation, each one of these technologies would not be trusted as a 'last line of defense' but when the entire system is considered, then I don't have a problem with this aspect of NAS.

I am still in two minds about NAS, but surely if the technology allows us to advance and make the airspace more user friendly for all while raising capacity and at the same time without impinging on the operations of the big boys, then I am all for it.
That's just it; you are talking about 'radar' alerts; the problems are not where we will have radar and the paints are showing; it's everywhere else, 85% is outside or below radar, so no collision alerts there I'm affraid.

How many alerts are 'real'; if TCAS was as unreliable as TAAATS alerts, you'd have thrown them out before you installed them. Example today, IFR in C A090, overflew a IFR in G showing A084 (maintaing A080) opposite direction, the Short Term Collision Alert (STCA) went off after they had passed, then it stayed active, i.e. telling me wrong info for 4 minutes.

Use the technology, awsure, as a user the technology sucks; we keep saying it, nobody listens because it's the 'worlds best'. Only automated system, blah blah blah, french rubbish that needs multi millions spent on it to correct the 19000+ software issues (non critical faults), let alone improved, modern functionallity.

Bottle of Rum

ftrplt 11th Nov 2003 13:03

I havent seen the new charts yet, has anyone looked at the steps to see if there is an issue for RPT on descent into airports where Class A overlies Class C? (i.e 747 descents into Sydney etc). Is it going to only be an issue for descent into Class D 'Airspaced' airports?

Some other points:

- ICAO specifies max 250 below 10000 in Class C, D, E, F and G (i.e anywhere). Why hasnt this been carried over? It must surely help just a little bit in a head-on separation scenario?

- The Military low jet route issues is covered in the US by publishing IFR and VFR low jet routes, and displaying them on all the Low charts. You are required to 'book' a route for a specified entry and exit time' which is then used to alert other aricraft. You have no route flexibility in the US system.

snarek 12th Nov 2003 07:58

AOPA Members, triadic et al
I have posted some questions on the AOPA Forum re NAS.


The Board will have a specific vote on certain features, like freqs on charts, in the near future and I want to make sure I include all your thoughts.

Please go there and let me know what you think.

Edited to answer plazbot.

It is a bit more complex than that, suffice to say there are some concerns now amongst some members.

However what will be will be, we will fly the maps, accept some input and go back with suggestions for change (if any).

That's the process.


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