Bik, you appear to display a remarkable level of flexibility with your ‘facts’.
The NAS, facts and fantasies
Just the facts, Maam :
FACT : The sky is very large.
FACT : Aircraft are very small (compared to the size of the sky).
FACT : The random chance of a mid-air collision decreases with the cube of the distance away from the airport.
FACT : The primary mid-air collision risk mitigator in the enroute environment is the :
Big Sky Theory
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.
NB : Whether or not a pilot maintains a vigilant look-out has no bearing on any of the above factors.
NB : Whether or not a pilot listens to a particular air traffic control radio frequency has no bearing on any of the above factors.
NB : Whether or not a pilot talks on a particular air traffic control radio frequency has no bearing on any of the above factors.
NB : Whether or not an aircraft has TCAS or ADSB fitted has no bearing on any of the above factors.
True, simply ‘listening’ and ‘talking’ have no bearing on the chances of avoiding a mid-air collision. You might as well be singing Auld Lang Syne on the radio of that is all you are going to do. Listening and
reacting to other traffic or control instructions does have a bearing in avoiding mid-air collisions.
FACT : In order to further reduce the chance of a mid-air collision airline aircraft are required by regulation to be fitted with TCAS II.
FACT : TCAS II systems are commercially available to anyone who wants one.
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?
FACT : VFR aircraft in class E airspace are required by regulation to carry and use an altitude-encoding transponder so that they are conspicuous to TCAS equipped aircraft.
FACT : TCAS equipped aircraft are aware of the position of nearby transponding aircraft.
NB : Whether or not a piece of airspace is within any kind of air traffic control radar coverage has no bearing on any of the above factors.
NB : Whether or not a third-party air traffic control service is aware of the position of VFR traffic has no bearing on any of the above factors.
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.
FACT : VFR aircraft have been flying unannounced in class G airspace since the AMATS changes of 1991 – in many places sharing the airspace with airline aircraft.
VFR aircraft have ‘announced’ through broadcasts. It is precisely this that Dick Smith has been trying to avoid.
FACT : For over a decade IFR aircraft in class G airspace have not been given traffic information on VFR aircraft, and VFR aircraft in class G airspace have not been given traffic information on other VFR aircraft.
Where traffic has been known (e.g. in radar coverage) traffic has been and continues to be provided.
FACT : Since the AMATS changes of 1991 there have been zero mid-air collisions in the enroute environment. (Despite the dire predictions of the flight service officers’ trade union at the time.)
True
FACT : In areas of high traffic density (like the terminal area around an airport) it’s important that pilots know where the other aircraft are.
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.)
FACT : TCAS and ADSB allow the pilots to know where the other aircraft are.
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.
FACT : It is very easy for pilots in the terminal area near to an airport to avoid a mid-air collision by using a combination of the airport traffic radio frequency, TCAS, and looking out the window.
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.
FACT : Pilots have been required by regulation to look out the window in order to avoid a mid-air collision for many decades : Refer CAR 163A.
Excellent point. Even though in Clas 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.)
FACT : Whether or not a third-party air traffic control service knows where the aircraft are is largely irrelevant as long as the pilots know where the aircraft are.
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.
Here’s a few popular fantasies :
I won’t comment on these.
Comment :
In my view the proposal to change some of the existing Australian class G (that uses ICAO class F procedures) to class E is two (or perhaps one) step(s) in the wrong direction. I don’t believe it’s needed - it’s simply over servicing and will lead to unnecessary delays and expense. It’s a solution in search of a problem.
But in my view the proposal to change some of the existing class C to class E is two steps in the right direction because it will reduce unnecessary delays and expense.
If the proposal were to change existing class C to genuine ICAO class G then that would be four steps in the right direction (ICAO-G = no service, no charge, no delay).
Class G = Good enough for me.
But if the general public demand that airline jets operating between capital cities be positively separated from other IFR aircraft then :
Class E = Good enough for everyone.
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. By the same token, they would prefer to avoid mountains, mountain goats, tall trees, balloons and other objects likely to interrupt the drinks service.