First Word: 01/08


General aviation seems to be always girding for the next big fight for its survival. If its not user fees, security restrictions or fuel prices, its the constant rear-guard action against local airport closures. For 2008 and beyond, the epic battle may be over the continued availability of 100LL avgas.

Environmental groups have revived the effort to have the Environmental Protection Agency regulate 100LL out of existence. At the risk of being labeled a tree-hugging heretic, I wont mind a bit if EPA finally agrees that leaded avgas has to go. Lets look at this rationally.

100 LL Avgas


First, although no one could argue that leaded fuels are remotely green, its also true that avgas represents such a tiny slice of the worlds refined fuel supplies that the volume of lead is miniscule.

Compared to the impact of millions of cars spewing lead-laced exhaust during the 1970s, which is what spurred the Clean Air Act and the elimination of leaded motor fuels, piston aircraft lead emissions are trivial. There are issues with spillage, storage and handling, both in the delivery chain and at airports, but again, there are larger environmental fish to fry than this.

And this is why general aviation has enjoyed a nearly three-decade excusal from finding another fuel that doesnt contain lead. During the 1970s, the aviation industry convinced Congress-rightly-that it was simply too small to have meaningful environmental impact and the technology didnt exist to either formulate a fuel or build ignition systems that would allow high compression aircraft engines to run without detonation on unleaded fuels. But in exchange for the 100LL dispensation, the industry promised Congress it would work on it. Thirty years later, we still dont have a readily fieldable solution in the U.S.

Why? Because with 100LL comfortably available for what has been perceived to be forever, there has been no urgency. And even such solutions as have emerged-electronic ignitions and fuels like 90/96UL-havent made significant market inroads because, well, why should owners buy these things when 100LL remains readily available? The immortality of 100LL has effectively stunted the technological progress that normal markets traditionally drive. In that sense, the industry did itself no favor when it got what amounts to permanent special dispensation from Congress.

What about the cost of converting to a new fuel? Its a case of pay now or pay later. Weve proven that 70 percent of the fleet can operate on 90/96UL, which, if widely distributed, might be a little more expensive than 100LL, but wont require engine modifications. The problem children are the remaining 30 percent of airplanes whose high-compression engines require high-octane fuel to run safely without detonation. For these engines, weve further proven that electronic ignitions can vary timing sufficiently to prevent detonation.

A decade ago, Continental fielded what has become its PowerLink FADEC system, but thus far, it has found few takers. General Aviation Modifications has its promising PRISM system, but it too is stuck in developmental never-never land.

Why? One reason, albeit not the only one, is that with 100LL available, theres no compelling economic incentive to give these systems the Manhattan Project treatment. And until that happens, well never advance them through the developmental hoops that will refine them to become the sophisticated fuel/ignition systems we should have had years ago. And we would have, had it not been for-and you can see it coming-100LL.

So this time around, my view is that its time to let leaded fuel sail into the sunset. We need to embrace this idea and, establish a real, no-kidding timeline to get it done. We should get ahead of the wave before Friends of the Earth and others of its ilk shove it down our throats on their schedule, not ours.

-Paul Bertorelli

Paul Bertorelli is Aviation Consumer’s Editor at Large. In addition to his valued contributions to Aviation Consumer, his in-depth video productions on sister publication AVweb cover a wide variety of topics that greatly contribute to safety, operation and aircraft ownership. When Paul isn’t writing or filming, he’s out flying his J3 Cub.