Merged: The Ambidji Report – CASA should get their money back!
So Leadsled, after that spiel, introducing ICAO airpsace will solve all our problems? I say "not likely".
My dear chap, that is not what I said,and you know it.
If you think I did say that, could I suggest a remedial reading and comprehension course, or re-read what I have said, having removed your fogged up goggles --- probably caused by too much heavy breathing.
I am not going to bother repeating what I have written several times, why bother, you don't want to know.
Tootle pip!!
Clinton,
Some joker one said: 'Statistics are like a bikini, what they reveal is interesting, what they conceal is vital".
MACs, around GAAPs or anywhere, are a very (thankfully) rare occurrence. As to whether the hours for all Australian aviation are enough to be able to draw conclusions that are statistically valid --- the "probable answer" is --- yes, no or maybe ---- depending on your point of view.
Are we using statistics in spite of, not because of, their validity. Rightly or wrongly, we do us them. All to often for seriously wrong purposes. The plight of flying schools in GAAPs, their continued viability, is very seriously in doubt, because seriously flawed conclusion from sparse data has, in my opinion, been misapplied ---- I would just love to know who really advised John McCormick.
Re. the "jet fatality rate", "jet" airline aircraft are a small total of the fleet, have a look at fleet hours, the one undeniable is that the majority of passengers exposed to any aeronautical risk travel on HCRPT jet aircraft, regardless of hours flown, sectors, takeoff and landings and so on, any of the "exposure rates" puzzled over.
The one "constant" that always surprised me is the categories of all the accidents, or more correctly, the similarities in accidents, regardless of the "culture" of the state/regulator. Thinx?? Maybe we should do a study of the quality versus the quantity of enforcement, and whether improved air safety outcomes are the aim, versus ---- scalps on belts, or "enforcement revenue" meeting and exceeding budget targets.
Even though I think FAA/FSF/AOPA/EAA/NBAA/ATA etc. have done a good job in the area of low speed handling accidents, for FAAland it is the rate that has been lowered, not the proportion of accidents attributed to handling errors, versus CFIT or VFR into IMC, compared to here or the western European states.
Thus, handling standards/errors are still well up the FAA priority list, despite the lowered rates over the last 15-20 years.
Until something better comes along, we are stuck with what we have, the one thing I am certain about, is that the overall and category record of the US, their air safety outcomes, are head and shoulders above the rest of us.
Comparatively speaking, Australia ain't too bad, but not nearly as good as we think we are, or as good as we should be. You would be a game person to ignore what US has achieved, but for various not very meritorious reasons, we ignore or discount
the US record time and again. Such is nationalism.
Tootle pip!!
Some joker one said: 'Statistics are like a bikini, what they reveal is interesting, what they conceal is vital".
MACs, around GAAPs or anywhere, are a very (thankfully) rare occurrence. As to whether the hours for all Australian aviation are enough to be able to draw conclusions that are statistically valid --- the "probable answer" is --- yes, no or maybe ---- depending on your point of view.
Are we using statistics in spite of, not because of, their validity. Rightly or wrongly, we do us them. All to often for seriously wrong purposes. The plight of flying schools in GAAPs, their continued viability, is very seriously in doubt, because seriously flawed conclusion from sparse data has, in my opinion, been misapplied ---- I would just love to know who really advised John McCormick.
Re. the "jet fatality rate", "jet" airline aircraft are a small total of the fleet, have a look at fleet hours, the one undeniable is that the majority of passengers exposed to any aeronautical risk travel on HCRPT jet aircraft, regardless of hours flown, sectors, takeoff and landings and so on, any of the "exposure rates" puzzled over.
The one "constant" that always surprised me is the categories of all the accidents, or more correctly, the similarities in accidents, regardless of the "culture" of the state/regulator. Thinx?? Maybe we should do a study of the quality versus the quantity of enforcement, and whether improved air safety outcomes are the aim, versus ---- scalps on belts, or "enforcement revenue" meeting and exceeding budget targets.
Even though I think FAA/FSF/AOPA/EAA/NBAA/ATA etc. have done a good job in the area of low speed handling accidents, for FAAland it is the rate that has been lowered, not the proportion of accidents attributed to handling errors, versus CFIT or VFR into IMC, compared to here or the western European states.
Thus, handling standards/errors are still well up the FAA priority list, despite the lowered rates over the last 15-20 years.
Until something better comes along, we are stuck with what we have, the one thing I am certain about, is that the overall and category record of the US, their air safety outcomes, are head and shoulders above the rest of us.
Comparatively speaking, Australia ain't too bad, but not nearly as good as we think we are, or as good as we should be. You would be a game person to ignore what US has achieved, but for various not very meritorious reasons, we ignore or discount
the US record time and again. Such is nationalism.
Tootle pip!!
My feeling is that our MAC occurrences are so low that they probably fall into the "poop sometimes happens" category ... and that we may spend millions of dollars changing, amending, creating, harmonising airspace ... for no decrease in the MAC figures. Is it really possible to get it to nil, or is there always going to be a certain number of MACs per year?
And another thing ....
Was just thinking about the reliability of aviation statistics and the following scenario came to mind. All the figures are just made up.
Say, the big fella in the sky has decided that, at an aerodrome with 100,000 movements per year, the law of averages will dictate that there are 3 MACs per year.
Now, say, in the country of Gamaria, there is not a large spread of flying activity outside of such aerodromes. Therefore the percentage of MACs per year would be artificially higher than say, in a country with the same number of aircraft and flying hours ... but with a much wider spread of aviation activity outside such aerodromes.
Could we substitute Australia and the USA in this scenario?
My point is that if we are to compare safety records ... comparing events per aircraft or flying hour is not necessarily a valid technique ... without taking into account many other significant factors.
Was just thinking about the reliability of aviation statistics and the following scenario came to mind. All the figures are just made up.
Say, the big fella in the sky has decided that, at an aerodrome with 100,000 movements per year, the law of averages will dictate that there are 3 MACs per year.
Now, say, in the country of Gamaria, there is not a large spread of flying activity outside of such aerodromes. Therefore the percentage of MACs per year would be artificially higher than say, in a country with the same number of aircraft and flying hours ... but with a much wider spread of aviation activity outside such aerodromes.
Could we substitute Australia and the USA in this scenario?
My point is that if we are to compare safety records ... comparing events per aircraft or flying hour is not necessarily a valid technique ... without taking into account many other significant factors.
Join Date: Sep 2009
Location: Sydney
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
How to analyse the small number of MAC’s in Oz? Some have said the number is small enough to look at each accident individually. Yes that’s fine – but that does not negate the value of a statistical approach.
And the best statistical approach is start with the exponentially reducing weighting which I described. This applied to each GAAP aerodrome individually, to yield the best estimate of current MAC rates. (Later a model is fitted to those averages).
Others have said “poop happens” at random - and there is no point in analysing the MAC numbers.
And Peuce wrote in #281: “My point is that if we are to compare safety records [over countries with different conditions], then comparing events per aircraft or flying hour is not necessarily a valid technique ... without taking into account many other significant factors”.
Yes quite. This brings in the second stage - modelling. When the common sense is implemented in mathematics, this field is called “analysis of variation”. One measures the overall variability of the data, then applies a candidate model, and recalculates the residual variation. If it is much less, then the model was a good one.
That is what I did. Using only the traffic at each aerodrome (pretty obvious), there was a clear reduction in variation, so that is an important factor.
Then I applied my second hunch – congestion at the boundary – and, after tuning, this reduced the variation further, so that factor is likely to be a real contributor also.
This does not rule other relevant factors - but they would belong in a more detailed layer.
Finally, this model is, I hold, the best estimate for the future, and should be taken as the “baseline MAC rate”. Being about half the Ambidji figure, it (along with the other errors) overturns their conclusions.
Leadsled #273 wrote:
“…one could easily get the impression that MACs were the biggest air safety problem in Australia.”
Yes, the Ambidji report reads as if midairs were the ONLY problem in Australia – because their brief was to investigate ATC under GAAP, which clearly affect mid-airs but less other accidents.
Their problem is that in they go on to draw conclusions about the total individual risk (to each pilot), and the total societal risk (to all pilots collectively) – after considering only one contribution.
They do not even mention single-aircraft accidents which are much more frequent. Nor do they mention ANY accidents outside GAAP procedures. No do they mention risk to third parties, ie those on the ground.
For example, according to Aviation Statistics, there were 1896 single-AC accidents in the last 10 years, but only 24 MACs. (Unfortunately their breakdown does not extend to fatalities.)
Leadsled wrote:
“Some time ago, a study was commissioned, using well known insurance co. investigators, and independent (of underwriters and the aviation sector) statisticians…”
Do you have a name or reference for that please?
And the best statistical approach is start with the exponentially reducing weighting which I described. This applied to each GAAP aerodrome individually, to yield the best estimate of current MAC rates. (Later a model is fitted to those averages).
Others have said “poop happens” at random - and there is no point in analysing the MAC numbers.
And Peuce wrote in #281: “My point is that if we are to compare safety records [over countries with different conditions], then comparing events per aircraft or flying hour is not necessarily a valid technique ... without taking into account many other significant factors”.
Yes quite. This brings in the second stage - modelling. When the common sense is implemented in mathematics, this field is called “analysis of variation”. One measures the overall variability of the data, then applies a candidate model, and recalculates the residual variation. If it is much less, then the model was a good one.
That is what I did. Using only the traffic at each aerodrome (pretty obvious), there was a clear reduction in variation, so that is an important factor.
Then I applied my second hunch – congestion at the boundary – and, after tuning, this reduced the variation further, so that factor is likely to be a real contributor also.
This does not rule other relevant factors - but they would belong in a more detailed layer.
Finally, this model is, I hold, the best estimate for the future, and should be taken as the “baseline MAC rate”. Being about half the Ambidji figure, it (along with the other errors) overturns their conclusions.
Leadsled #273 wrote:
“…one could easily get the impression that MACs were the biggest air safety problem in Australia.”
Yes, the Ambidji report reads as if midairs were the ONLY problem in Australia – because their brief was to investigate ATC under GAAP, which clearly affect mid-airs but less other accidents.
Their problem is that in they go on to draw conclusions about the total individual risk (to each pilot), and the total societal risk (to all pilots collectively) – after considering only one contribution.
They do not even mention single-aircraft accidents which are much more frequent. Nor do they mention ANY accidents outside GAAP procedures. No do they mention risk to third parties, ie those on the ground.
For example, according to Aviation Statistics, there were 1896 single-AC accidents in the last 10 years, but only 24 MACs. (Unfortunately their breakdown does not extend to fatalities.)
Leadsled wrote:
“Some time ago, a study was commissioned, using well known insurance co. investigators, and independent (of underwriters and the aviation sector) statisticians…”
Do you have a name or reference for that please?
there is not a large spread of flying activity outside of such aerodromes. Therefore the percentage of MACs per year would be artificially higher than say, in a country with the same number of aircraft and flying hours ... but with a much wider spread of aviation activity outside such aerodromes.
As for Leadsled's:
One of the problems we have here, is the belief that Australia has the world's best air safety record, a severe case of "rose coloured glasses". We are fond of quoting "jet fatalities", and can't even get that right, we have had one, wiped out most of the Mareeba Council, but we confine ourselves to "RPT" jet, and pat ourselves on the back. Selectively narrow down the definitions enough, and the record will always be perfect
Last edited by Capn Bloggs; 22nd Sep 2009 at 03:56.
Then I applied my second hunch – congestion at the boundary – and, after tuning, this reduced the variation further, so that factor is likely to be a real contributor also.
Ian, if you must follow a model, have a look at the stats from here and what the FAA studied in pilot visual acquisition of traffic.
Take note of the figures resulting in reduced radio congestion and enhanced traffic acquisition...what we are all about in dirt road class G. Less time on the radio and more time acquiring targets...the technolgy that enhances this is worth a hundred years of statistical studies into accidents.
A13% increase in positive sighting reports with a corresponding decrease to near zero (2%) of a negative sighting report as opposed to 18% without a CDTI.
Take note of the figures resulting in reduced radio congestion and enhanced traffic acquisition...what we are all about in dirt road class G. Less time on the radio and more time acquiring targets...the technolgy that enhances this is worth a hundred years of statistical studies into accidents.
These devices will enable pilots to acquire the aircraft and verify the identity of any intruder within the general area either before, or in accordance with, a controller-issued traffic advisory or alert.
