tobzalp
....you make a statement that the public want Big jets separated from IFR and E makes this all OK. Do the public even know what IFR is.
No – I’m quite certain that they don’t.
Just the same as the general public think that there is an air traffic control tower at every two-bit country airstrip, and that an aircraft will crash if it attempts to fly without filing a flight plan.
Away from the airport class G would be plenty good enough. Class E is just to keep up appearances (kind of like the way non-radar class D control zones do now).
VFR Flying Jacket Crowd = Volvo Drivers of the sky.
Cowboys = Volvo Drivers of the Sky.
Get it yet?
Oh yes – I get it. In fact, I think I first
got it quite some time ago.
What I
get is that a worryingly significant number of air traffic controllers have an unhealthy and disrespectfully condescending attitude towards the pilots of private category flights (ie their
“customers”).
I’m sure that this attitude contributes, in part at least, to many of the all-too-common
“remain outside controlled airspace – clearance not available” rebuffs.
The air traffic control system has been primarily designed to cater for scheduled IFR traffic – basically, for RPT. The air traffic control system has real problems coping with the more random nature of unscheduled traffic, and in particular with VFR GA traffic.
The ridiculous amount of TAAATS data-input required when pop-up traffic requests a clearance is an example of this.
Thankfully, the vast majority of GA traffic has no real need for any type of
“service” from the air traffic control system.
Class E at least relieves the air traffic control system of the apparent burden of having to deal with VFR GA traffic. With class E the air traffic controllers are free to
“roger” and
“wilco” their way through the day with their captive audience of IFR traffic (at enormous expense), leaving the VFR traffic to get on with it, unhindered by the delays (and expense) of the air traffic control system.
Four Seven Eleven,
Scenario : B737 descending through class E airspace, being radar vectored for sequencing at a controlled aerodrome. The pilot spots an unidentified aircraft and determines that a collision risk exists . No traffic information has been passed by ATC. What happens now?
1. Does the pilot deviate from his vector/ route clearance?
2. Does the pilot deviate from his level assignment?
The pilot manoeuvres as required to avoid the collision risk.
Actually – I was faced with a very similar scenario a few months back in class C airspace.
When being radar vectored for an ILS approach in day VMC conditions I noticed a parachute canopy (with a person dangling beneath it) in my 12 o’clock, about half a mile, slightly above, and with a very low rate of descent. It looked like a regular parachute, but it may have been one of those fancy ones that can go up as well as down. I was at 5,000 feet on a left base with about 18 track miles to run. As I was about to take action to alter course so that I would pass laterally clear, the canopy rolled right 90 degrees and commenced a rapid descent. It seemed apparent that the parachutist had seen (or possibly heard) me coming and had decided that it was in their best interests to get out of the way. In the end I could see that there was no need for me to alter course.
Once clear I reported the sighting to ATC who helpfully told me
“no traffic, no traffic”.
Is that the kind of scenario you are getting at,
Four Seven Eleven? If so, then I’m sure it’s all been done before.
In particular, if anyone has relevant experience in how RPT jets operate in non-radar E airspace in the USA, your input would be very worthwhile.
Forgive me - I’m not sure if this relates to your earlier scenario or not. But if it does, how can an aircraft be radar vectored when it is outside radar coverage?
Surely we could have called it something like IFR Uncleared Transition in E - or IFR UTE for short.
Excellent idea!
How very Australian.
Shall we have a government funded committee debate for months whether it should be a HOLDEN ute or a FORD ute?
gaunty,
Long time no seeum, great chat the other night.
Yeah – and if you keep up that kind of behaviour then you can expect to be hearing from my lawyers!
(With a cheque for AOPA membership....
)
I had a very good run with Volvos....
Yeah – I learnt to drive in one myself. They’re great cars! As they say :
“boxy, but safe”.
(Actually, I learnt to drive in two Volvos – one 1,700 kg one and one 14,900 kg one.)
How come these left-wing socialists want to pick on Volvo drivers all of a sudden? Me thinks it’s just penis-envy from the peasants.
Circa 1969 and I'm standing on the tarmac at Perth Airport being roundly berated by an apoplectic airline captain for having the temerity to;
a. operate an aircraft in IMC within 100nm of his AIRLINE AIRCRAFT (F27)
I’m sorry – but I nearly fell off my chair at that one! I thought you said
“airline aircraft”?
Your F27 driver sounds like a typical big fish in a little pond. How many gold bars did he have? PMSL!
Four Seven Eleven,
And where traffic levels warrant it, the primary mitigator is supplemented by secondary, tertiary etc. mitigators, such as traffic information, control etc. No airspace system relies only on this primary mitigator. No safe transport system does.
Herein lies the crux of the debate :
“where traffic levels warrant it”.
In my opinion the traffic levels in the vast majority of Australia’s airspace warrant nothing more than genuine ICAO class G (ie no service, no delay, no charge).
I do agree that in areas of high traffic density (like in the terminal area around a very busy airport) the
Big Sky Theory is not enough on its own.
But whereas you might suggest further layers of collision risk mitigation based on an expensive air traffic control infrastructure – like DTI or controlled airspace, I would advocate less restrictive, less labour-intensive, and more effective solutions - like using a TCAS traffic display and like looking out the window.
In the Australian enroute environment the random chance of a mid-air collision is sufficiently remote to rely on the
Big Sky Theory on its own.
True, simply ‘listening’ and ‘talking’ have no bearing on the chances of avoiding a mid-air collision.
With respect, I suspect that you might have missed the point. I do admit that I might have been a bit too obtuse.
My comments were not in regard to
“the chances of avoiding a mid-air collision”.
My point was that the
Big Sky Theory functions just as well whether you talk on the radio or not, and whether you are in radar coverage or not, and whether you have TCAS or ADSB or not, because the geometry of a very large sky with relatively few aeroplanes flying around in it is unaffected by all those things.
Although why you would want one if it has no bearing on ‘the above factors’ is beyond me. Perhaps it is because TCAS does in fact offer a supplementary level of safety?
Of course TCAS offers a further level of safety over and above what is available from the
Big Sky Theory on its own.
I think this relates to my apparently obtuse point above.
Thanks to the
Big Sky Theory there is an extremely remote chance that an aircraft will be involved in a mid-air collision in Australia’s enroute environment – whether the aircraft has TCAS or not.
If the aircraft has TCAS then the chance of a mid-air collision is reduced even further.
Anyone who is concerned about a mid-air collision should buy a TCAS.
True, but does not tell the full story. Merely being aware of the current position of conflicting traffic is not the same as being aware of the other traffic’s intentions, nor does it afford the opportunity to negotiate mutual avoiding action, either directly or via a third party.
I disagree.
Intentions are wonderful (eg
“climbing to altitude 5,000 feet”), but useless. What matters is what the other aircraft is
actually doing (eg erroneously climbing to 8,000 feet).
TCAS calculates the
closure rate and
time to closest point of approach of nearby aircraft. These are the all-important factors, not what the pilot of the other aircraft
intended to do.
A TCAS traffic display allows the pilot to see the
relative position and altitude of nearby traffic. Aircraft that are climbing or descending are shown as such. It is very easy for a pilot to manoeuvre around other traffic using a TCAS traffic display.
In any case, if both aircraft are fitted with TCAS II then mutual avoiding action will be automatically calculated (and co-ordinated) by the TCAS units themselves.
If one aircraft is fitted with TCAS II but the other aircraft is not then TCAS II will still automatically calculate avoiding action.
VFR aircraft have ‘announced’ through broadcasts. It is precisely this that Dick Smith has been trying to avoid.
What proportion of VFR aircraft do you say make these broadcasts?
Despite all the VFR waffle on the airwaves, my information is that something less than 20% of VFR pilots make radio transmissions in class G airspace (other than on CTAF or MBZ frequencies).
For the vast majority of VFR traffic in the enroute environment it has been the
Big Sky Theory alone that has kept the planes apart for over a decade.
Where traffic has been known (e.g. in radar coverage) traffic has been and continues to be provided.
Fantastic. So if you’ve got radar, where’s the problem with class E? If you haven’t got radar then you haven’t known about the VFR traffic (and therefore have not passed DTI on it) since the AMATS changes of 1991. Either way – same result : ZERO enroute mid-air collisions since 1991. Again, where’s the problem?
Wrong. It is important that someone knows the positions, intentions etc of aircraft so that a cogent plan can be formulated which provides – dare I say it – a ‘safe, orderly and expeditious’ flow of air traffic. (We can’t all be number one in the sequence.)
We will continue to disagree on this point. I suspect that our differing opinions are based on our different experiences.
TCAS shows the positions of transponding traffic. ADSB will, in the future, do many things. ADSB will be akin to an ashtray on a motorbike on November 27.
To be entirely honest, I haven’t yet figured out what ADSB can do for me that TCAS doesn’t already do. I’ll stick to TCAS for now, thanks.
Operations in the terminal area involve much more than avoidance of a mid-air collision. The ‘ease’ with which terminal area operations can be conducted safely would, I suggest, be dependent on the traffic levels, complexity, weather etc. A point will be reached when it becomes less easy, difficult and ultimately impossible.
Again – I suspect that our differing opinions are based on our different experiences.
Excellent point. Even though in Class A airspace, the current primary mitigator against mid-air collisions is ATC, the regulators have long recognised that reliance on one, single mitigator is unsatisfactory. This is exactly why we have a ‘layered defence’. If ATC fails, pilot situational awareness may detect it. If not, then TCAS. If not, then ‘see and avoid’. (Not forgetting ‘luck’ or big sky theories.)
Whereas for a whole lot less money we could rely on the
Big Sky Theory as the primary risk mitigator, use TCAS as the secondary risk mitigator, and have looking out the window as the last line of defence. (I presume we are talking about the enroute environment here.)
One of the many problems with the current, outdated air traffic control procedures is that they
increase the chance of a mid-air collision by funnelling all the aircraft into the same few flight levels along the same routes -
reducing the effectiveness of the
Big Sky Theory.
Knowing where the aircraft are is the very smallest part of a safe air traffic management system. The reason controllers (Say in class A) know where the aircraft are is because they ‘put’ them there. They did this because they knew the positions, intentions etc. of other aircraft. They plan for safety. By doing this, pilots can, in most cases fly more directly, staying at the same levels for longer, thus saving money.
The day you come up with an air traffic control procedure that can get me a more expeditious routing than direct to the destination is the day that I’ll be your biggest advocate.
But until that day comes I’ll continue to view the air traffic control system as an elaborate and expensive system of traffic lights in the sky – their only possible effect being delay and expense.
As has been pointed out already, the public do not want to be ‘positively separated from other IFR aircraft’. They probably want to avoid mid-air collisions altogether.
I concur.
But I suggest that once an aircraft is away from the airport environment it doesn’t need any air traffic control service in order to avoid a mid-air collision.
triadic,
As professionals (and that includes amateur professionals, or is that the professional amateurs?) I believe that none of these associations would use the safety argument if they did not believe it was valid to do so.
Your belief in the altruism of the Australian union movement is much greater than mine.
The "I only want what is good for me" position is unbalanced and inappropriate to the discussion. We must consider the whole picture and how each of us interacts with other users. To do less, dare I say… is not professional.
I disagree.
If everyone lobbied for what is best for them then we ought to end up with a solution that offers the greatest benefit to the greatest number of people.
Isn’t that how a democracy is meant to work?
Certainly the big sky policy is a significant mitigator in terms of a possible mid-air collision, however I know at least one regional airline pilot that had a very close call with a glider in en-route airspace (above 5000ft) a few years back. By the time they saw each other there was no time to move and the glider went under the regional turbo-prop by only a matter of metres – a close one.
I’m sorry – didn’t you say they missed?
Where’s the problem then?
A miss is as good as five miles.
Bonzer,
None of the reresentatives from the AFAP AIPA or Civilair are paid for their time, they just happen to care about the safety of ALL airspace users.
Oh come now – get real.
Civil Air represents the interests of the air traffic controllers.
AFAP and AIPA represent the interests of the RPT pilots (who are just a small fraction of the total pilot population).
To suggest otherwise is either disingenuous or naďve.