Scottie - "Most competent Doctors are able (sooner or later) to move onwards and upwards into very well paid..." Depends what you mean by "very well paid" and where you are. Very few of us are as wealthy as you suggest.
"..and very secure positions for the last 3rd of their working careers."
Physical fitness requirements are naturally less than for pilots, but your implication of a universal sinecure is far from correct.
"...a flick through the UK tabloids will unearth story after story of malpractice / negligence / incompetence in the medical profession."
Yup. But how many of these turn out to be true and are properly substantiated? How many complaints does the General Medical Council [GMC] receive yearly (many thousands) and how many result in disciplinary measures (very few). This is not a reflection on the zeal of the GMC [which has been restructured to include a large proportion of lay persons] to protect the public (this is now their motto, as if all doctors were intrinsically venal or incompetent), but rather a true figure for the number of unfit doctors.
Some sort of system of revalidation of doctors is currently in place and under very active development in most 1st World countries.
So much for "...since the medical profession will never allow such testing..." !!!
Currently one technique is the system of "Continuing Professional Development" (CPD) points. In order to continue in practice, doctors must rack up X number of CPD points per year. Points are awarded for attending conferences or seminars or filling in MCQ questionnaires at the end of journals to show that one has at least read the article or articles in question. Getting the required number of points is ludicrously easy and proves nothing at all. CPD rewarded drug company sponsored "seminars" (with snacks) have become an industry in themselves. This is not a criticism of a good concept but of it's implementation (quite difficult if it is to be meaningful).
"Performance Assessment" is difficult when the long-term results of a treatment or operation only become apparent years in the future. Proper auditing is expensive, extremely labour intensive and requires not only real actuarial skills but also an in-depth knowlege of medicine and the disease process and procedures in question [this isn't to say that it can't or shouldn't be done]. The long training and stringent recruitment culls all but a microscopic proportion of the truly incompetent. We can all recognise gross incompetence when we see it, but marginal performers are more difficult - for by whose standards do you judge? Of course we all aspire to the impeccable results produced by the handful of academic world experts in whatever it is we do, but are we coalface workers to be reprimanded if we fall short? When the well-funded international expert (who often does little else) boasts a 0.5% complication rate for a procedure, when are we considered derelict? 2%? 5%? 10%? It all depends which of the myriad of available procedures we are talking about and where and under what circumstances it was performed.
"free from the worries of.....testing of his professional skills." Come on now. We are all tested every single day of the week (and often at weekends) whereas pilots are tested only when they are flying or in a sim(which is a lot less than that).
Unfortunately we don't have simulators of sufficient sophistication to allow genuine testing of our abilities and decision making skills. I wish we did - it would make my life as a trainer a great deal easier and allow me to do "dry-runs" of procedures that I perform infrequently.
The problem with this discussion is that although there are superficial resemblances between the life and work of doctors and pilots, they really are very different. We are not perfect,but some members seem to have (doubtless through no fault of their own) rather worrying views about our morals and attitude to our work. Obviously that we don't project too well.
Having said that, I think that we have a great deal to learn from the aviation industry. In particular, we have no formal training in CRM and indeed the term is unfamilar to most doctors. PPRuNe has stimulated me to read and learn about techniques of CRM and attempt to put them into place in my environment with some success, so perhaps Danny has achieved more than he bargained for.