anecdotally...
... it has been my experience, in twenty or so years of hitching rides on Sov (and ex-Sov) freighters into Sudan, and DRC, and Bosnia, and Nagorno Karabagh, and Afghanistan, and a dozen other places where only fools travel lightly, that most - very nearly all - the aircrew on these aircraft are ex- military. Same goes for a lot of the chopper pilots that get chartered to lift stuff in (and people out) of miserable places.
I had a beer (or ten - and that's another aspect of the problem) with an Mi-17 pilot in Mozambique a couple of years ago, and he said you should never fly with anyone under 45. Older than that, and they'll have been trained properly in the old USS-of-R. Under that, and they probably didn't.
They have a somewhat more casual attitude to The Rules than most pilots. And of course the bottle of vodka that usually has a place near the throttle quadrant just makes it easier.
Many of them are outstanding pilots and engineers, keeping these old birds running when they really should be on the scrap heap.
But every now and again they'll mess it up.