The Fight Over Avgas
Can private pilots fly unleaded?
- By David Freed
- Air & Space magazine, August 2013
Photo-illustration by Théo. Nozzles by Chad Slattery. Airfield © 2012 Marc Espolet / iStockphoto.
(Page 5 of 6)
GAMI president Tim Roehl knows well the complications. Roehl says it will likely take two to five years before his company’s G100UL fuel will be available commercially. Unlike Swift Fuel’s avgas, G100UL is made entirely of highly refined petroleum components.
Roehl co-founded the company in 1994 with fellow aeronautical engineer George Braly in order to obtain an FAA Supplementary Type Certificate to install balanced fuel injectors on Continental Motors engines, as well as a Parts Manufacturing Approval to make them. When the EPA began pushing to do away with lead in aviation fuel, GAMI began testing fuel and additive combinations on its own. The company, which today has about 50 employees, conducted tests on a handful of combinations before settling on the one it dubbed G100UL.
GAMI believes it can achieve fleetwide use of its fuel within two years, says Roehl, by first winning Supplementary Type Certificate approval on an aircraft-model-by-model basis. The company recently completed the required FAA flight testing following more than two years of extensive testing using a high-compression, turbocharged Cirrus powered by G100UL fuel. The airplane, says Roehl, performed flawlessly.
There are still numerous regulatory hoops to jump through before any alternative fuel can make it to the pump. While the government mandates that autogas meet only four basic parameters, avgas is held to no less than 44 measurements to ensure its uniformity and, thus, reliability. Everything from freezing point to electrical conductivity to corrosivity is calibrated. Those assessments take time. And so, for the foreseeable future, the future of what makes general aviation run remains in limbo.
Many companies around the globe once produced tetraethyl lead for aviation. Today there is only one: Innospec Specialty Chemicals. Based in Britain, Innospec buys elemental lead mined in places like Australia and China, cooks it at high temperature, and ships it to petroleum refiners internationally, including about a half-dozen in the United States. A few countries, such as Algeria, Iraq, and Yemen, still burn leaded car gas and import tetraethyl lead for that purpose, but the vast majority of the chemical, says Innospec vice president Brian Watt, ends up in the fuel tanks of airplanes like mine.
In 1998, sales of tetraethyl lead accounted for more than 90 percent of Innospec’s overall revenue. Today, it’s less than 15 percent and dropping. With a weakening consumer market and broad consensus that lead is harmful to the body, how much longer does Innospec envision producing and distributing liquefied lead?
“Innospec is committed to working with the aviation industry,” Watt told me in an email, “and will continue to supply TEL for aviation gasoline while there is demand from the industry.”
But what happens if and when that industry’s consumer demands are cut off by government order? Will there be a viable fuel substitute in place before then? And at what cost? Will a new fuel require me to make major engine modifications? For a 2,000-hour overhaul of my powerplant, I recently spent more than $20,000. I’d rather not endure that kind of pain again anytime soon, even to go green.