C210_Flyer wrote:
If people didnt die of lead poisoning during the 60s than they are not goint to have health problems from the amount GA puts into the atmosphere.
Ah, okay, in this case we can go on that way of course 
Ethanol is an alternate to lead in fuels, now used universally, and it’s been conclusively proven to be deadly to humans over many centuries of experience. Despite that, I intentionally drink it almost every day without issue. What’s apparently relevant is the amount of exposure
I think the issue with lead in Avgas is that given how it’s used, and how much is used, nobody gets enough exposure to make any difference to their health. If I were a lineboy (who knows, it might happen after I retire!) I’d be carefully to keep it off my hands, just as I would to avoid benzene exposure from unleaded fuel.
IMHO that the high volume of lead in Avgas shows how far behind aircraft engine technology really is.
I also think that the overall amount, worldwide, is too small to do much harm … but there might be places with lots of traffic, airports inside cities (some in L.A. come to mind) where it could be a health factor.
Alexis wrote:
IMHO that the high volume of lead in Avgas shows how far behind aircraft engine technology really is.
But the majority of aircraft engines don’t need the lead at all.
Most of the bigger ones do, as far as I know, and many of the smaller higher compression ones aswell. For example the O-320 with 150 hp in my Warrior can be MoGas certified, the higher compression 160 hp version not – as far as I know.
Alexis wrote:
For example the O-320 with 150 hp in my Warrior can be MoGas certified, the higher compression 160 hp version not – as far as I know.
The “high” (it isn’t really) compression 160hp version will run on 91UL unleaded avgas though, as will most of them.
The issue is the small minority of engines that cannot run on an existing unleaded avgas are also the ones that burn the majority of the fuel. An airport manager really doesn’t want to have multiple grades of fuel at the airport, so they will choose the one everything can run on, even if most of the aircraft can run on 91UL.
Yes, you are right! I completely forgot that … It’s mainly Continental engines like my IO-550 that are not approved.
would like to work for the clean tech industry and i found many interesting companies but don’t you think for instance if I say that my passion is aviation, love planes, i love to fly etc, how it is going to be perceived
It will be extremely well perceived if you tell them that you need to learn to fly in order to pioneer green techs in aviation like Solar Impulse.
How much fuel do you think that Bertrand Piccard and André Borschberg burned before they circumnavigated the planet with a solar powered plane?
What about Gérard Feldzer before he became an environmentalist?
All turbo engines, and many others. I think a CR above about 9 is a no go.
One US Experimental engine builder told me 9.0:1 is OK for 91UL but not 9.5:1.
Nobody ever claimed that leaded petrol was causing people to drop like flies – just that exposure to it takes a few points off the average iq, adds a bit to your blood pressure, makes you a bit less fertile… The sort of things that you don’t notice on an individual basis but that are significant on a population level.
In the quantities used in Avgas I think the biggest risk is to pilots. I usually get some on me when I go flying and would opt for Ul91 if I could.
