Comments

kmisegades, I think that Greg's point is that there are quite a few people who are fun fliers, but who operate relatively "big iron" that they bought at relatively low prices because the equipment is now quite old. Those people are not rich. They can't afford the cost of converting/upgrading their engines to take modern fuels. If the fuel available at the airport isn't at least 100 octane, they fear they will not be able to fly at all. The wealthier types and business fliers have more money, and in any case they fly enough that their next "natural" overhaul will be within a few years anyway. But the people flying for fun, operating larger engines in older aircraft, get stuck in the middle. They are the ones who get grounded if a "fix" isn't found, and since they don't fly a lot, their next "natural" overhaul may be 15 years away. The additional difficulty is that the cost of installing a 3rd set of fuel pumps doesn't make sense for most operators. They will sell Jet A, and some type of avgas, but that's it. I don't think there will be 2 types of avgas unless it's mandated as a condition of selling the Jet A - something I don't see happening. It's possible we'll see smaller airports switch to Jet A/unleaded, and others to Jet A/100 octane, which might be an interesting idea (for both). The economics of specialty fuel have never made much sense, which is why avgas has always been one or (at most) two suppliers away from extinction, and only its extraordinarily high price has kept it alive. Locking ourselves permanently into that model makes no sense to me, and this seems like an excellent opportunity to move away from it, toward a (relatively) non-specialty fuel (ethanol-free mogas). I agree that this would leave a few people in a very sticky spot. I do agree that there needs to be a transitional solution for those people - but it should be transitional, rather than locking us into a high-priced specialty fuel in perpetuity. I don't know what that transitional solution would be - affordable electronic ignition, separately-sold fuel additives, some combination thereof, perhaps. It needs to be something that can get most of those people to their next overhaul at no more than modest cost (partially offset, one hopes, by the cheaper fuel). Greg, I admit I don't know how much the "big" engines get derated when they run on lower-octane gas with electronic ignition, but I doubt that you'd find your range reduced. More likely it would be extended for two reasons. One is, IIRC, that the energy content of low-octane fuel is actually higher, per unit volume or mass, although the difference is small. The other is that, at lower power settings, you'll get better fuel economy (of course, you can do this now, so if you don't it suggests you prefer speed to range). Small comfort, I suspect, but the catastrophe would be less complete than you imagine.