Unleaded avgas a hot button issue gas variables pogil extension questions

The other big factor is how pilots operate their aircraft. In the lab testing of these fuels, the engines are operated properly. Unfortunately, once the fuels reach the real world, pilots may operate their engines outside the recommended parameters, which may increase the possibilities of recession.

Some of the other comments concerned the question about how the original 100LL was approved in the 1970s. There was very little testing then because 100LL met the performance parameters of the old 100/130 spec. The only difference between 100/130 and 100LL is the limit on the lead and the dye color. Most people do not realize that 100LL is correctly called 100/130 low lead.

Finally, people are concerned about the fact that only one plant produces the lead mixture used in 100LL. While this is true, there are other plants in the world that could be started up to produce the product if the need and economic potential should arise.

Now I know that the removal of lead is a hot button issue for many people. But unfortunately, claiming that there will not be a problem will not change reality. And if you talk to knowledgeable rebuilders, exhaust valve recession is a very real problem.

It was bad enough in the ’70’s when 80/87 was phased out. Those engines (and there were many) not designed to guzzle 100/130, or the later 100LL, were forced to do just that. All sorts of new operational and maintenance issues ensued, to include stuck valves, carbon and lead-choked cylinder heads and ring grooves, and fouled spark plugs. This made flying even more costly.

Now the policy afoot is to eliminate all tetraethyl lead from avgas, which will most assuredly introduce new operational and maintenance issues in these same engines. This will increase the cost of flying even more, in ways not yet fully known. I don’t give two hoots what some 250 hour block runs may or may not show…..that isn’t now, nor has it ever been “real world”. Perhaps this no-lead push is to placate a horde of environmental tree-hugger weenies. Well.

But since the consumption of avgas in this country is way less than one half of one percent of total gasoline production, just what impact to the environment does lead in 100 LL have, and is the amount of money being wasted in an attempt to supplant it a smart, wise or logical expense? The sane answer is a resounding “NO” !

I’ve enjoyed Ben Visser’s articles concerning Unleaded Fuels. I am squarely on the side of the anti lead side due to the copious amounts of science concerning lead on the environment and the health of people. Our club airplanes all run, very well, thank you, on Unleaded MOGAS.

But the problem was created by the automotive and oil industries, not by the do-gooders. The problems of lead were addressed in the 20’s with even New York City banning leaded fuel. The auto and oil industries sued and eventually NY City had to change the law, and, hence industry fought every effort to ban lead up through the 70’s.

So instead of conducting the research and engineering over decades, we are now finding that kicking the can down the street has run out of street. And now it is airplane owners paying the price and so blame the environmentalists, instead of placing blame on those that fought against regulation for all those years. But I have faith in American imagination and creativity to overcome the issue.