[Peetwo]

McKenzie vs CASA Avmed - latest update 19/12/18.

Off the UP with the ongoing saga of CM vs CASA Avmed; Fight Engineer gets my vote for most common sense response(s) to now resident Avmed CASA sexual Nowluke...

Fight_Engineer

There's one small problem for those excusing CASA's appeal to "prudent caution": one of CASA's own published Aviation Medicine case studies.

It's the one describing "Jim's" stroke at age 76, which finally grounds him (just in case this, my first PPRuNe post, does not permit URLs, and any of you need to search).

In this case study, CASA describes grounding a pilot who has a stroke, at the age of 76. This means, by CASA's own documentation, CASA continued to renew Jim's Class 1 medical certificate (with conditions) when Jim was aged 75, and diagnosed with Type 2 diabetes, and known to have high cholesterol and high blood pressure. 

Here are some "medical" stats:
1. The absolute annual risk of one quite severe medical condition (mild death, with recurring symptoms) for the average75 year old Australian male is about 4%. Just go to the ABS and take a look at the life tables to confirm. 5% annual chance of death is reached at about age 77 for the average Australian male.
2. Life expectancy for people with Type 2 diabetes is substantially reduced, possibly up to 10 years. If I need to find credible data, I will, but I am sure the forum medical experts will have such data on-hand and should be happy to quote.
3. Thus, the absolute annual risk of death for 75 year old "Jim" with diabetes, plus CASA-documented high cholesterol, plus CASA-documented high blood pressure is "significant" / "non-trivial". You don't need advanced maths/stats to know that it's "significantly higher" than the 4% annual risk for the average 75 year old male. As a guide, IFF the life expectancy for a Type 2 diabetic Australian male is, say 75, then Jim had a 50% total chance of already being dead at the age CASA renewed his Class 1 medical certificate. Despite my limited medical expertise, I am confident that death is regarded as an incapacitating condition with substantial negative consequences, even among lay-people. And that's before we consider what other non-death incapacitations diabetic old "Jim" might also be at a higher risk of suffering (it's debatable whether we should lump in the full risk of Jim's actual factual stroke with the general elevated risk factors already identified for Jim - it's a veritable smorgasbord of possibilities for his age and documented conditions).

I have read the Ambekar and Adamczyk studies, and it is not credible to contend that CASA's approach between Clinton's case and Jim's case is objectively consistent from a statistical safety-driven standpoint. The only way to get close (from a statistical risk viewpoint) is to assume that the consequences of (just a) recurrence of a DAVF after having been "nominally cured" (ie. Clinton's current state) is worse than the consequences of actual death. I don't need to be a specialist in anything, or beat my chest about experience/qualifications to state authoritatively that the incapacitation consequences of DAVF recurrence cannot be worse than the incapacitation consequences of death.

So, for those of you who think CASA's approach in these two cases is "consistent", please explain what stats, studies and numbers you are using to justify your "trumps". For me, it's just about the numbers - and using population-level stats, plus CASA's own published information and cited studies, their approach to pilot incapacitation risk/safety cannot be described as consistent in these two cases.

It's also obvious that if the default approach is: " we're not sure, so we'll ground if in doubt and defend initial decisions no matter what", then pilots have a strong vested interest in never revealing anything voluntarily to their regular GP or "DAME". That's objectively a sub-standard outcome.

And a CASA medical officer who effectively instructs an "independent expert" doesn't seem confident that his own conclusions will be confirmed. This behaviour is indefensible [in a decision review scenario].

And Nowluke's response:

For Flight_Engineer - your assumptions and conclusions are incorrect. Whilst death is an outcome for everyone and its all cause rate after a certain age approaches 100% (somewhere near 117). This does not then mean that the risk acceptance threshold changes or if your other condition risks are less than this then the system is flawed. As before, the risk decision is composed of the full view of the "rate of unacceptability at which the hazard is realised when an appreciation of the condition in the environment is made with respect to the standards acceptable within the safety management system. This rate is whatever is set by the regulator and it is the best that can be made with the scientific, not single expert, knowledge available". Yes death is a single event, yes it is pretty bad (for the individual and whoever is nearby in the aircraft) but whilst the individual effect is large, the statistical event risk is lower than a plethora of other safety significant events (or risks of events).


The hazard is not death (although that is an outcome), it is the condition or treatment causing impairment &/or incapacity &/or death &/or the aviation environment effects and/or mitigations on the condition over the term of the licence.

I would be surprised to hear of anyone flying on a Class 1 CPL/ATPL internationally over 65 and domestically without investigations every 6 months and would also be surprised if companies employ them (in a passenger flying role) over 70 (and only domestic multi-crew) at all for broader insurability reasons (partly due to that all cause death rate you raise). Noted though there are some QFI/FIs flying students well into late 60's/early 70's, again with some pretty strict conditions. 

The proposal of "never tell anyone" about medical issues and describes an attitude of wilful violation of the broader safety system and a lack of integrity. The, "I know best" and "if you mention anything you'll be grounded" combination will undermine safety even when there isn't mistrust in the system- and there are no quick fixes when those under regulation actively undermine that system. It is also under-appreciated that the decisions that are made are in the broader public interest rather than the individual. 

It's nowhere near perfect and people will be upset, your response to actively mismanage one's own occupational healthcare puts others lives, property and reputation at risk in a repugnant and self-indulgent way that no one would reasonably support.

If you transcribed some of these conditions under discussion to the engineering space and started talking about 15%, 40% yearly failure rates or degradations of critical engine/flight surface parts then I'd say there would be some spirited discussion of continuing to use those parts...

Vis your magical Jim, no idea what the detail is. You could very easily sign off on anyone on a class 2 for VFR, daytime flying in remote contexts and then restrict the operating area - i.e. cattle surveying/remote property access work in a defined area and then add on multi crew restrictions or time limits, whatever mitigates the risk, in context, to an acceptable level. If the risk is indeterminate or there are multiple risks/risk factors then a conservative approach is always going to be the case. The other considerations though are much lowered if the only victim is yourself and your private property. Similar processes occur in the road transport context. The regulator is not going to do the legwork to demonstrate or research these mitigations without government direction.

To which Sunfish responded:

Nowluke, you are either a troll or wilfully ignorant about the subject of risk. There are rigorous processes for managing risk available right now ((even from ICAO) that you do not seem to have any understanding of, or, like the regulator, CASA, you do know but prefer your own brand of self serving necromancy to established fact,


Quote:

This rate is whatever is set by the regulator and it is the best that can be made with the scientific, not single expert, knowledge available".

There are current ICAO standards for the probability of death via aviation, there are also numerous actuarial metrics. From memory we are talking of the order of forty million to one. These are internationally accepted standards for risk. Neither CASA nor the AAT seems to make use of these datums which is a crime.

Quote:

The proposal of "never tell anyone" about medical issues and describes an attitude of wilful violation of the broader safety system and a lack of integrity. The, "I know best" and "if you mention anything you'll be grounded" combination will undermine safety even when there isn't mistrust in the system- and there are no quick fixes when those under regulation actively undermine that system. It is also under-appreciated that the decisions that are made are in the broader public interest rather than the individual.


It's nowhere near perfect and people will be upset, your response to actively mismanage one's own occupational healthcare puts others lives, property and reputation at risk in a repugnant and self-indulgent way that no one would reasonably support.

Sanctimonious codswallop. The alleged "broader safety system" lacks even a shred of integrity as evidenced by the regularly reported bizarre behaviour of CASA staff including Avmed and despite the numerous pleadings, reviews and negotiations attempted by industry. Given that the system is broken there is no safety case to undermine.

As for your appeal to "the public interest" you must be joking. To educate you, any test of what "the public interest' is actually involves two components; the cost to the community of an event (a medical incapacitation causing an accident) versus the cost to the community of mitigating the risk of said accident. IT IS THIS SECOND HALF OF THE EQUATION THAT IS NEVER CONSIDERED BY YOU AND CASA - AND THOSE COSTS ARE HORRENDOUS!!!!!

The result is a system of regulation that has destroyed thousands of jobs and billions in investment (let alone opportunity costs) without saving the community from any meaningful expense at all. So much for your notion of public interest. You have to take into account the cost to the community of regulation and this seems to have escaped both CASA and you. Again there are ICAO metrics and procedures available right now to do these calculations.

Other jurisdictions have considerably better and more relaxed regulatory environments. Their publics profit from it and their skies aren't raining aluminium either.

Inevitably Nowluke responded...

ICAO provides a medical framework which Australia/CASA aligns to in our environment, large portions will be wholly adopted or partially will be with localising changes and there will be exceptions. I am familiar with the medical standards and know there is a large amount of flexibility in their application and guess what, a nation can put any further restrictions or exemptions in place that it feels are necessary. These deviations are on the air services website. The loose wording of the standards, I would say, purposefully allows a large amount of latitude for medical issues. Further, for this case, ICAO is silent on these clinical particulars.


I don't agree with your goading tirade or the position that some enormous harm is being manifested. Your absolute position- that it's all f#%$ed, no planes are crashing and there's river of cash and jobs we're missing out on sounds like a politician's fever dream. Unfortunately there is a culture of grievance and refusal to accept a situation when it doesn't match an entitled opinion. If there is such a swathe of systemic issues then stand up a (new) senate committee or write to your MP and put them to light. Blowing hard on the internet's not likely to do much.

I agree the system has (not insurmountable) issues and in the medical space it can be extremely difficult to run a situation down to a statistical value. As I've repeatedly said, you're never going to have a regulatory organisation accept a critical/catastrophic risk scenario in the absence of quality data without a period of non-event to support it. End of.

+

...because there is quality data that those risks are improbable or negligible (post mitigations)...

+

vis Jim, it all appears pretty reasonable, he probably would have met the threshold in some guidelines for some more invasive cardiac screening (CCT/Angio) years before his stroke if you take him as a Class 1 who does single pilot air show work and some instructing. Retrospectively his condition may have been present for a number of years prior and wasn't/couldn't be detected. If all of the required/indicated investigations were negative and then guidelines stratified him into lower risk cohorts of diabetic, hypertensive elderly men he may not be (in the narrative he obviously isn't') above the level where his Class 1 is revoked. What's the exact issue? There is a conflict though at around that age, where as it was raised, it doesn't really matter how many negative tests you have, it's getting close to closing time percentage wise- this conflict I understand is based on age discrimination issues, you can't blanketly revoke licences on that basis and there aren't sensitive enough tests to demonstrate prospectively what pathology Jim has.


Post his event they made him fly privately with QFI only as a mitigation as out of 100 Jims much more than 1% will suffer an incident, not going to be a fun day for the QFI though as Jim's 10 through 38 keel over and not appropriate to have it occur in a commercial context i.e. multicrew as a mitigation (although it could be feasible in a younger, less comorbid individual as their culminative hazard would be less but that's a different story).

Boy this guy loves the code from his keyboard...
But then FE in true right of reply retort said...

Nowluke... I think your post at 13:11 is quite revealing. Firstly, I made no assumptions, except ones which are inarguably obvious. Obvious, like, I don't need to see a double blind peer-reviewed study with controls to know, say, that parachutes save lives.


Secondly - and not that it matters in the context of this discussion - I am not (and never have been) a pilot, and have very little to do with aviation other than as a regular passenger on typical commercial airlines. "My" response is an objective analysis of comparative data and CASA's decisions based on that data. Whatever assertion you make about "me" in regard to the effects CASA actions will have on whether actual pilots reveal medical information is (like some of your qualitative maths) way off the mark. If the regulator appears to punish honesty and (more importantly) obstinately defends/protects its own decisions from new information and independent review, then the end result will be increased dishonesty = reduced safety. Whether you or I like it is irrelevant - unless you are a person with responsibility in the field. If you are, I counsel against denial.

"My" magical "Jim" is described in CASA's own published case study. I cannot post links (yet), otherwise I would have saved you 5 secs of search.

I suggest you read its details very, very carefully and understand fully the facts it reveals, and then try again to credibly defend your carefully crafted claptrap - after recovering from your surprise. It's clear you did not read the Case Study, when you theorise about all those mitigating restrictions which were not placed on Jim's flying. Similarly, disingenuously quoting failure rates of 15% to 40% in engineered parts as if these are the numbers that equate to Clinton's incapacitation risk was the icing on the cake.

I will repeat for you, but I know your opinion is set (perhaps you should apply for a job at CASA - or better still, don't): despite the comparative stats and data/studies available, CASA's application of stats for safety risk assessment between Clinton's case and "Jim's" case is inconsistent.

To which old mate Nowluke could not help himself...

See above? or as copied Retrospectively his condition may have been present for a number of years prior and wasn't/couldn't be detected. If all of the required/indicated investigations were negative and then guidelines stratified him into lower risk cohorts of diabetic, hypertensive elderly men he may not be (in the narrative he obviously isn't') above the level where his Class 1 is revoked. 


That said, it's a narrative story with none of the references to the decision makers reasoning or guidelines/evidence applied to underpin the decision. His changing licence restrictions aren't annotated as he aged into the 60+ zone nor are the frequency and types of tests he most definitely would have needed prior to then to support the decision i.e. ATPL loss, CPL loss or restrictions etc. In the absence of these, and a point where you are correct, is that his baseline risk, without investigation would have likely precluded his renewal. 

It's a repetition of previous, "here's a "safe" apple!!!!!" "now apply it to my orange". "Here's a single related story, and I say CASA got it wrong!!!!" therefore "everything must be wrong!!!" 

The percentages were not linked to anything, just that they were in a range where it is not negligible and it's not above odds- I don't think Clinton in this case (and I'm not spending a couple of hours trawling through neuro/radiology journals) has a clearly evidenced prospective risk percentage (for or against a renewal), hence the waiting period/non consideration (as I understand it) for 12 months. I don't think the CASA decision reasoning has ever been fully placed on here, only Clinton's interpretation/recall of it and my perspective on what the reasoning possibly was.

Not to be out done FE come back with...

Quote:
Originally Posted by Nowluke 

vis Jim, it all appears pretty reasonable, he probably would have met the threshold in some guidelines for some more invasive cardiac screening (CCT/Angio) years before his stroke if you take him as a Class 1 who does single pilot air show work and some instructing. Retrospectively his condition may have been present for a number of years prior and wasn't/couldn't be detected. If all of the required/indicated investigations were negative and then guidelines stratified him into lower risk cohorts of diabetic, hypertensive elderly men he may not be (in the narrative he obviously isn't') above the level where his Class 1 is revoked. What's the exact issue? There is a conflict though at around that age, where as it was raised, it doesn't really matter how many negative tests you have, it's getting close to closing time percentage wise- this conflict I understand is based on age discrimination issues, you can't blanketly revoke licences on that basis and there aren't sensitive enough tests to demonstrate prospectively what pathology Jim has.

And yet, despite all that extensive, invasive screening, investigations, long history and stratification into lower risk cohorts (presumably by individual experts) among the large statistical population of Type 2 diabetics, Jim then went on to have a "surprise" stroke before the year was out. Perhaps if CASA had used this case study to then document and publish some revised, substantially more cautious approach to dealing with the patently obvious high risk Jim posed, then that might justify CASA's inconsistent statistical approach in these two cases. That's the exact issue. You, and CASA, have used the fewer (but still sufficient for statistical analysis) data points associated with "nominally cured" DAVFs as a blanket excuse to bend the incapacitation risk to a level the data/maths does not support.

 
Classic! And a chocfrog for Fight Engineer -