So that car makers, in face of ever more stringent safety demands, saw only the option of putting in more (low-grade) steel.
And on that you would be wrong. There is way more 'exotic' light material in a car today. Unfortunately, there is way more safety, emission, and customer preference (like A/c power everything and noise insulation) equipment on a modern car.
Have you ever wondered why the midsize car empty mass has increased from say 800kg to well over 1.5t during the last 20 years?
Yes, I often have. Had always believed the technological progress would make room for lighter cars (pleasing the green horde who want lower emissions i.e. less fuel burn) while still increasing safety, but my only explanation is that carbonfibre and like technologies are either too expensive or not sufficiently mastered yet to make it into a volume product like a car. So that car makers, in face of ever more stringent safety demands, saw only the option of putting in more (low-grade) steel.
can be addressed by making it more difficult (i.e. mandate more and better training and maybe regular skills tests) to operate fast/complex/difficult aeroplanes.
I think the state already interferes with our lives WAY too much, so no, I don't think more regulation is the answer. What may well be needed is an overhaul of the training syllabus, certainly in Europe at PPL level (which is mostly what we are discussing here).
my car has ABS, I rather like it.
Have you ever wondered why the midsize car empty mass has increased from say 800kg to well over 1.5t during the last 20 years?
Now how much payload would be left in your aircraft when you double its empty weight? Mine would be approximately at -300lb.
Mass may not be that important for cars (although it's underestimated, the higher the mass, the more difficult it becomes to reach CO_2 emission standards) , but for aircraft, it's of prime importance.
I like the way the avoids crashes on the roads
At least the advertising agency was worth its money. Every statistic I have seen suggests that ABS had negligible impact on safety. Insurances initially offered a rebate for cars with ABS, but soon stopped that when they learned it didn't have a material impact on statistic.
At Friedrichshafen, there was an interesting presentation by Bill Schinstock, Manager Regulations and Policy Section, Small Airplane Directorate of the FAA. A few key point from his presentation:
So from this it directly follows that making FAR23 certification even more expensive and constraining will make FAR23 aircraft even less appealing. So IMO correctly the FAA concluded that FAR23 regulation should be scaled back, not the opposite, what you're suggesting. So there's now a FAR23 rewrite in progress at the FAA. How quickly that progresses we will see, in light of the sequestration I'm not holding my breath.
... my car has ABS, I rather like it.
Sure. But a well trained driver can stop his car in a shorter distance whilst still having full control without ABS (that's why most race cars come without it). I stand my point that training achieves more with less effort than constantly upgrading the hardware. And the issue that "half of all people have below average intelligence and half of all people have below average discipline" can be addressed by making it more difficult (i.e. mandate more and better training and maybe regular skills tests) to operate fast/complex/difficult aeroplanes.
Tomjnx - my car has ABS, I rather like it. I like the way the avoids crashes on the roads, the results aren't nice and fitting ABS to new cars isn't such a difficult task.
We should in aviation stop aspiring to bad design and somethings about our airplanes are simply bad design. They won't be found in 200 years time - because some generation of pilots will think its all nuts and demand better.
imagine we could eliminate 35% of accidents by taking some really easy steps
Do we even want to?
Your list of what the regulator should ban makes CS23 aircraft even less appealing than they already are. Guess why the action now happens at relatively unregulated UL or VLA aircraft?
I don't think a world where government makes it impossible for its subjects to shoot themselves into their foot is worth living.
Most traffic accidents could probably be avoided if cars were banned and horse carts mandated instead. Do we want this? Me - no.
Well - the fantasy that pilots can be trained must be stopped at the realization that half of all people have below average intelligence and half of all people have below average discipline - we can not change this.
So if we want to stop accidents, we need to accept that different people have different skills, abilities to focus and disciplines. If I were a regulator, I would ban new installations of engines subject to carb ice, autopilots that can stall an airplane and vacuum pumps (who ever thought of such a silly idea as making a life-saving device a moving part?). Frankly speaking, I'd ban fuel systems in new CS23 aircraft where a pilot can run out of fuel with a tank still full.
Regulators seem to regulate form filling and where they could add value, they don't. My simple point is, imagine we could eliminate 35% of accidents by taking some really easy steps - why not take these and then work on training for the other 65% of accidents?
What I meant was the Cessna "both" position.
Some classic piston aircraft had barometric mixture controls, why not all?
Possibly because
the compensation does not work completely, due to not fully compensating for the mass flow of air as you climb, so manual leaning is still needed to maintain the engine operating point
the diaphragm is a popular failure point, which stops the engine dead when it breaks (unless you are very quick on pulling back the mixture lever)
I don't think the mixture lever system represents any significant pilot workload, of all the things a pilot needs to do, or know about. Especially as 99% of GA flies at very low levels, so you just climb up to cruise, set 23"/2400 and peak EGT, and that's it. You can land like that also...
The biggest single gotcha IMHO are the crap fuel gauges, and crap pilot training when it comes to fuel flow, and trip planning.
And carb icing 
But I'd guess that the automation and envelope protection helps crap crews to survive longer...
I think that is absolutely the name of the game today.
Every individual has a personal risk level he's comfortable with, if the environment becomes safer than this level, he will compensate by more risky behaviour.
My guess is that we're operating close to this comfortable risk level.
If we make the aircraft safer (eg. using Garmin ESP, Synthetic Vision, Automated Fuel Management, or even a Parachute), we won't reduce the accident rate, but will increase the dispatch rate, as pilots will go closer to the limits.
Envelope protection: Airbuses have had that since quite some time. Despite it, some crews still managed to exceed the envelope and crash.
But I'd guess that the automation and envelope protection helps crap crews to survive longer...
