I found Bik's post so impressive that as an amateur I am wary of dissenting, but two points seemed to be a generalisation a little too far:
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"By classifying the AIAAs as class G the UK government is tacitly suggesting that it’s perfectly safe - anyone is allowed to fly there at anytime. If it wasn’t safe to fly there then the government would not have classified it as class G."
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Perfect safety is unattainable - if the Government/CAA/NATS or whoever has a tacit position, it is that there is an acceptable level of risk, which is around 10 to the -8 or so per flight. If you look at what actually kills people in UK airliners, collisions with military (or anything else) in class G is historically less than dropping Tridents onto Staines, fires at Manchester, hitting motorway embankments after shutting down the wrong engine, and taking your chances with various foreign places. Including risks to third parties, there is also the issue of getting lumps of blue ice, inter alia, or even whole Korean airliners, fall out of the sky.
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"Which leaves those aircraft without an automatic altitude reporting function. Various flying magazine advertisements show altitude encoding blind altimeters available in the UK, tax paid, for under £150. Is this too much to ask? I think not. "
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There is more to it than that. I fly a non-transponder glider and weigh 205 pounds including parachute, with a max cockpit weight allowed of 208. I use up the last three with water, food, and a logger (a black box recording my flight).
There is no £150 solution for me. What would be the price, even if I could accommodate the weight including another battery, the size in my already crowded cockpit, and whatever on my already full panel, for a transponder, + alt encoder, + fitting, + certification, for a non-standard installation?
I would guess that gliders comprise more of the UK traffic on good summer days than all the rest put together (an educated guess, based on extrapolation from the last published survey of UK airspace utilisation). Hardly any have, or could at present have, transponders. Ditto for many permit PFA-type aircraft.
I have no more wish to have a collison than anyone else, but what kills UK glider pilots historically is mostly self-inflicted - other forms of bad airmanship; then collision with other gliders; then collisions with GA traffic; and not yet with heavy stuff. Of course, the first time the latter happens it may swing the figures if the airliner is also mortally afflicted, and of course we don't want any of these things to happen, but the solutions have to practicable and affordable.
On a more general note, I am on the side of those who see airliners leaving controlled airspace by choice and mixing it with the military, me, and everyone else, to save fuel and/or keep routes "viable", as compromising their attitude to safety. It is an arguable position where there is no linking airspace, but questionable, showing profit triumphing over safety, where there is a protected but longer route available.
Where I found the BBC programs disturbing was the apparent continuing lack of willingness by the big professional outfits to invest in safety until forced to do so. E.g. Milan and ground radar. Or even Leeds. It just confirmed what I have seen over three decades - the big boys want safety when somebody else pays for it, e.g. by more controlled airspace which takes from me at no expense to them, but not in equally urgent and probably more life-saving potential but costly measures such as rear-facing seats, ways of getting passengers out of burning aircraft (a la Manchester), this new data link, video cameras to show which engine is really on fire (Kegworth), etc.
Chris N.