The biggest topic of discussion in general aviation these days is the effort to develop a 100-octane unleaded fuel that can be a drop-in replacement for 100LL.
It seems that everyone has an opinion about a solution, but there seems to be problems with every solution — problems that people try to overlook.
Over the holidays I was cruising the internet and came across a discussion on the unleaded avgas subject. One of the comments stated that since the EPA has established that leaded avgas represents a significant health hazard, it needs to be banned immediately. I was going to respond and point out the error of this statement, but in the holiday spirit I passed and had another eggnog.
The problem with the statement is that the EPA study did not in any way, shape, or form prove that leaded avgas is any kind of a health hazard. In fact, it did just the opposite.
It showed that a group of people trying to prove that leaded fuels are a health concern are wrong. I believe their data analysis concluded that there was no significant difference in blood lead levels between people living by an airport and the general population.
This is the same conclusion from a very large sampling in the late 1960s that compared the blood lead levels of taxi drivers in New York City to that of natives in Africa who had never seen an internal combustion engine run on leaded fuel. Even though the taxi drivers were around exhaust from cars burning leaded fuels every day, there was no significant difference to that of the natives who never came in contact with an engine burning leaded fuel.
So instead of reporting the results that the EPA found, they added a weasel word to their report to make it look like their tests supported their pre-drawn conclusions.
They reported that leaded avgas PROBABLY represented some kind of health hazard.
PROBABLY? If I had ever added this to the conclusion of a test program while working at Shell, I PROBABLY would have had a much shorter career there.
In the news they are always saying that we need to follow the facts and use good science.
Using those guidelines, I offer the following options on what path to follow:
Option 1
Scrap the whole 100 octane unleaded project for now and keep 100LL for the foreseeable future.
This will save about a dollar a gallon in fuel costs, protect everyone’s exhaust seats, and ensure a continued supply of safe fuels all across the county.
It will also give time to allow the unleaded fuel suppliers to solve their technical problems and maybe develop an unleaded fuel that can be used in the entire GA fleet with little or no significant technical problems.
Option 2
Do a gradual reduction in the lead level allowed.
Today a gallon of 100LL typically contains around 2.1 grams of tetraethyl lead (TEL).
Say we reduce that to 1 gram per gallon by 2035 and 0.5 grams by 2045.
This will allow the industry to gradually improve their fuels and the engine and engine component business to upgrade their products to work with the new fuels.
It will also allow those people who believe that one must follow the facts and the science only when it agrees with their pre-drawn conclusions to claim that they reduced the lead level in the atmosphere.
Option 3
Follow the current push to replace 100LL with 100UL by a specific date, like 2030 chosen by the Eliminate Aviation Gas Lead Emissions (EAGLE) initiative, a government-industry collaboration to make general aviation lead free.
This is the most expensive option with a lot of possible problems, such as exhaust valve recession, runoff water pollution, seal compatibility, spark plug fouling, and many more.
And it is not based on factual data or science.
Everyone has heard that lead is bad, but it has to be in a form that people can ingest. Lead is all around us in items such as car batteries, fishing lures, many shot gun shells, wheel weights for tires, and a lot of other industrial uses.
Hopefully we can get back to using factual data and good science to make decisions, not just opinions. But probably not.
