Is unleaded avgas coming?

[Rex Bueller]

AOPA: Court decision aids safe transition to unleaded avgas
By AOPA Communications staff
A U.S. District Court for the District of Columbia ruling has freed the Environmental Protection Agency (EPA) from having to make an accelerated endangerment finding on emissions from general aviation aircraft. This ruling will help to ensure that efforts to find an unleaded replacement fuel will continue in a manner that will guarantee aviation safety.
On March 27 the court ruled that the EPA has discretion to make endangerment findings under an important Clean Air Act provision, but cannot be forced to do so as Friends of the Earth had hoped. The EPA has already begun the endangerment process and will continue its efforts on a schedule driven by facts and policy, hopefully not by more lawsuits.

 

[Ted]

There have been efforts for years working towards unleaded AvGas. It will happen, but expect it to be 5-10 years away from reality in my book, combination of cert efforts and infrastructure.

 

[Skylane81E]

There have been efforts for years working towards unleaded AvGas. It will happen, but expect it to be 5-10 years away from reality in my book, combination of cert efforts and infrastructure.

My bets are closer to 20 years before it is really out there

 

[Ted]

My bets are closer to 20 years before it is really out there

Part of that depends on what the industry does.

Honestly, they make a much bigger deal over this than is necessary or prudent.

 

[poadeleted20]

Yes.




But not today.

 

[bnt83]

Yes.




But not today.

*Checks Calendar*

or tomorrow

 

[poadeleted20]

*Checks Calendar*

or tomorrow

As they say south of the border, "Mañana." Which does not really mean "tomorrow," but rather "not today" -- much like the Arabic "insh'Allah," meaning "in God's time," i.e., it will happen when God is ready for it to happen. Or maybe, "It'll be here when it gets here and not a second sooner."

 

[bnt83]

As they say south of the border, "Mañana." Which does not really mean "tomorrow," but rather "not today" -- much like the Arabic "insh'Allah," meaning "in God's time," i.e., it will happen when God is ready for it to happen. Or maybe, "It'll be here when it gets here and not a second sooner."

*Googles insh'Allah"

 

[bnt83]

*Googles Fort Hood shooter"

 

[cowman]

The better question is if it will be more or less expensive.

 

[bnt83]

The better question is if it will be more or less expensive.

Indeed

 

[Keith Lane]

The better question is if it will be more or less expensive.

Maybe you are new to aviation........

Less expensive????

 

[Alexb2000]

Jet-A seems to be the direction manufacturers are going. Probably to sell more aircraft into developing countries with little to no 100LL.

 

[Ted]

The better question is if it will be more or less expensive.

I think SwiftFuel's solution was expected aat $8/gallon. Not sure about G100UL. That number could be old, too.

Equal or less cost to 100LL is a requirement to be marketable.

 

[poadeleted20]

I think SwiftFuel's solution was expected aat $8/gallon. Not sure about G100UL. That number could be old, too.

Equal or less cost to 100LL is a requirement to be marketable.

Last time I heard their presentation last May, they said they thought could even slightly beat 100LL per-gallon prices. Further, due to the higher energy density, you'll only burn about 90% as many of those cheaper gallons. Now that would be a good deal! Just mind your weight calculations, as the stuff is that much heavier per gallon, but if you have the useful load available, range goes up with the same tanks.

 

[Ted]

Last time I heard their presentation last May, they said they thought could even slightly beat 100LL per-gallon prices. Further, due to the higher energy density, you'll only burn about 90% as many of those cheaper gallons. Now that would be a good deal! Just mind your weight calculations, as the stuff is that much heavier per gallon, but if you have the useful load available, range goes up with the same tanks.

Which "they", GAMI or Swift? I don't recall the weight issues, but I do remember that G100 has the benefit of higher energy density. Flew the GAMI SR22 Turbo with 100LL in one tank and G100 in the other. Saved about 1-2 gph on the G100 tank, same speed.

 

[bnt83]

Last time I heard their presentation last May, they said they thought could even slightly beat 100LL per-gallon prices. Further, due to the higher energy density, you'll only burn about 90% as many of those cheaper gallons. Now that would be a good deal! Just mind your weight calculations, as the stuff is that much heavier per gallon, but if you have the useful load available, range goes up with the same tanks.

+1 unaware of the weight difference.

 

[cowman]

I just filled up my car with 91 octane ethanol-free pump gas at just under $4/gallon. We know a great many GA engines are fine with that as-is, maybe with a different additive package out if the refinery that octane rating could go up a little and we'd be in a less specialized supply chain.

I wouldn't expect it to be a lot cheaper but $5-6/gallon seems at least plausible with that route.

 

[Ted]

I just filled up my car with 91 octane ethanol-free pump gas at just under $4/gallon. We know a great many GA engines are fine with that as-is, maybe with a different additive package out if the refinery that octane rating could go up a little and we'd be in a less specialized supply chain.

I wouldn't expect it to be a lot cheaper but $5-6/gallon seems at least plausible with that route.

This is a frequently produced argument that unfortunately gets lost in the realities.

Why did they stop selling 80? Lack of demand. When you look at the amount of 100LL sold by volume, about 80% of it gets used by planes that need it. Navajos, 421s, 402s, etc. Even though a larger number of planes have low power engines that are fine on 93 UL, those planes consume a much smaller amount of fuel and fly less. When I was flying the Navajo, one flight was 100+ gallons usually. And we flew often. Remember that we as an industry consume a very small amount of fuel compared to mogas or jet.

If you're ERAU, UND, etc and have an army of Skyhawks, then you benefit tremendously. You still need 100LL for transients, but you have large enough volume to make it work. For the rest of the airports in the country, the cost of having a second tank just doesn't pay off when those customers can use the fuel out of the first.

As an individual operator, you can make it work for you, as the folks who buy unleaded and tank it to themselves do. As a business trying to make money, nope.

 

[Morne]

As a business trying to make money, nope.

Ted,

That is supposition. Some folks are going to experiment in the 91 Octane MoGas market and see just how much (or how little) demand there really is. And you DON'T need to add a fixed tank to do that experiment.

The dislocation created by a leaded fuel in an unleaded world is severe. The added dislocation of zero ethanol in an ethanol world just makes things worse. But if you can find zero ethanol 91 Octane unleaded, and you make folks aware of its availability, you just might have a winner. Only time will tell.

Sure, back in the bad old days when high-compression piston twins ruled the sky you wouldn't settle for E0 91UL. There's a Colemill Baron at my field that we'll never sell a drop of 91UL to, and that's OK. But more homebuilts are started today than certified, where builders are smart to plan for 91UL MoGas use. And the upper end of the market burns Jet A. Left in the middle are the old birds like my 182E, which is eligible for (and has) an STC to use MoGas.

Once we get our MoGas option running at BJJ you should stop up and see how it goes. That is, if you can find a spot to park on the ramp what with the crowd of Stinsons, RVs, Grumman low wings and Cessna high wings waiting to fill up.

We're trying to find a way to better serve our aviation community. E0 91UL MoGas at a much lower price than 100LL is one such option.

 

[poadeleted20]

Which "they", GAMI or Swift?

Swift -- which is who you were talking about, I thought.

 

[poadeleted20]

Why did they stop selling 80? Lack of demand. When you look at the amount of 100LL sold by volume, about 80% of it gets used by planes that need it. Navajos, 421s, 402s, etc.

The FAA presentation I saw said 30% of the fleet requires 100 octane, but they burn 70% of the avgas -- which makes them the driver for the problem. If they all converted to kerosene engines, the remaining avgas market would not be sufficient to keep the price reasonable for the rest of us.

As for Morne's mogas argument, there are too many aircraft which lack mogas STC's, and they'd all be grounded without avgas.

 

[dell30rb]

We're trying to find a way to better serve our aviation community. E0 91UL MoGas at a much lower price than 100LL is one such option.

Glad you are doing that. Wish more airports would.

I think this is a chicken/egg problem. The airports don't sell mogas because there is not much demand for it. OTOH No one bothers with getting the STC for their plane because no one around them sells mogas, and the only options are haul it in 5gal cans or buy a trailer

 

[Morne]

As for Morne's mogas argument, there are too many aircraft which lack mogas STC's, and they'd all be grounded without avgas.

And I know there are lots of piston birds that can't get an STC. Fine and dandy. We're still going to carry 100LL Avgas for them.

But for those that can, which dominates the personal/hobby/training fliers, we'll have an option that costs $1.50/gallon less. How many times do we bemoan the fuel prices causing folks to fly less? Well here you go, a way to put gas in your bird and go fly on a sunny Saturday without having to pay $6+ for the leaded stuff that the DC-3s and other HP twins need.

Are we gonna sell as much MoGas as Avgas? Almost certainly not. But our approach is a lot better than waiting around for 10-20 years for the FAA to find a solution.

 

[tinerj]

Don't do today what you can get out of doing altogether.

 

[rottydaddy]

The better question is if it will be more or less expensive.

Hardly worth asking... at the rate we're going, before they pull the plug on 100LL it'll probably cost $15/gal here in the USA. At that point, they'll be able to charge what they want for the new stuff, and the gov't will still tax the hell out of it "just because".

It's depressing to think about, but we 'mericans have been living the high life as far as this stuff goes, and it looks like the party's over.
The only survivors will be engines that run on either Jet A or whatever cars are burning, I think.

 

[Ted]

That is supposition. Some folks are going to experiment in the 91 Octane MoGas market and see just how much (or how little) demand there really is. And you DON'T need to add a fixed tank to do that experiment

Well, as I alluded to with the ERAU/UND examples, there are isolated cases where it will work. You may find particular airports that have a high population of experimentals or other aircraft that can use the STC legally and you'll find a demand. On the whole, though, it just doesn't make sense at this point.

Now, let's say that an airport decides it wants to stock 93 UL fuel (which is legal on certain Lycoming engines at this point, although the airframes may not be approved for that fuel). Ok, ultimately they'll need a permanent distribution for the fuel, which will involve a permanent tank, with the cost, etc. associated with it. The FBO needs to believe that extra tank will provide it with enough business to justify the expense of purchasing and maintaining that equipment. Alternately, it would need to convert the 100LL tank to 93UL tank (which gets into a bunch of legal issues since it had lead in it), and then no longer provide 100LL. Now they've lost that customer base, whereas with the 93UL that would have only gained a probably small amount of business, from people who might specifically go to the airport for that fuel service.

Business wise for the AvGas GA fleet to be served, a single-fuel solution is what's best.

The FAA presentation I saw said 30% of the fleet requires 100 octane, but they burn 70% of the avgas -- which makes them the driver for the problem. If they all converted to kerosene engines, the remaining avgas market would not be sufficient to keep the price reasonable for the rest of us.

As for Morne's mogas argument, there are too many aircraft which lack mogas STC's, and they'd all be grounded without avgas.

That's the issue. The engine and the airframe need to be approved for it to be legal. In the experimental world, no big deal - it's experimental. In the certified world, which still makes up the majority of aircraft, there's some work to be done.

The numbers I heard were more like 20/80, but 30/70 is close, too.

 

[Ted]

Hardly worth asking... at the rate we're going, before they pull the plug on 100LL it'll probably cost $15/gal here in the USA. At that point, they'll be able to charge what they want for the new stuff, and the gov't will still tax the hell out of it "just because".

It's depressing to think about, but we 'mericans have been living the high life as far as this stuff goes, and it looks like the party's over.
The only survivors will be engines that run on either Jet A or whatever cars are burning, I think.

On the other hand, 100LL has been more or less pacing auto fuel percentage wise over the past 5 years with some peaks and valleys due to the lag between auto fuel and 100LL prices that exists. Plus, with the growing experimental market (not showing much in the way of signs of stopping), fuel and other options are expanding for aviation.

We have been living the high life, but AvGas as a whole is sticking around for a while. Plus, Jet-A options are growing.

 

[MSPAviator]

Are modern forms of mogas really that susceptible to vapor lock?

 

[JHW]

Are modern forms of mogas really that susceptible to vapor lock?

The difference is modern cars have pressurized fuel tanks and fuel injection supply pressure is much higher than the old carb fuel delivery. In a boat or airplane, vapor lock issues are unchanged whether it's 1963 or 2013

 

[N801BH]

Are modern forms of mogas really that susceptible to vapor lock?

Modern forms of mogas are the cheapest, least costly product the refiners can legally get away with... If you take a winter blend of some po dunk refiner and try to use it in the summer then vapor lock in certain applications, will have you dancing with the devil..

 

[Morne]

Business wise for the AvGas GA fleet to be served, a single-fuel solution is what's best.

Business wise but not technical wise. You're trying to shove one solution down the throat of everything from an A-65 to a TIO-541 to a TSIO-360 to a IGSO-480 to an O-320. Looking at that huge variation a multifuel strategy makes better sense.

Or, perhaps a single fuel strategy with a series of additives for certain difficult applications. Our Jet-A truck has a Prist injector that we can turn on or off, I can envision something similar for the AvGas of the future.

 

[PilotAlan]

Or, perhaps a single fuel strategy with a series of additives for certain difficult applications. Our Jet-A truck has a Prist injector that we can turn on or off, I can envision something similar for the AvGas of the future.

One thing unleaded AvGas will require is a fuel stabilizer, as AvGas sits in tanks a LOT longer than mogas. A truck full of mogas injecting something like StaBil would be a good thing. And some other type of additive reducing vapor lock issues.

 

[Ted]

Business wise but not technical wise. You're trying to shove one solution down the throat of everything from an A-65 to a TIO-541 to a TSIO-360 to a IGSO-480 to an O-320. Looking at that huge variation a multifuel strategy makes better sense.

Or, perhaps a single fuel strategy with a series of additives for certain difficult applications. Our Jet-A truck has a Prist injector that we can turn on or off, I can envision something similar for the AvGas of the future.

I agree that from a technical perspective, a multifuel strategy is better. Remember, I'm an engineer who used to have to deal with these issues for a living. So at the risk of sounding arrogant, I'd say I have a pretty decent handle on the factors involved.

Again, the problem comes down to having apppropriate fuel stocked at an infrastructure level. There are a lot of regulations surrounding storage and distribution and fuel, which lead to high costs if you want to offer multiple fuel types. Many airports only have 100LL or Jet A. Why do you think that is? It's because they can only make enough money on fuel sales to justify the one.

The additive strategy could work, but I think would be hard to implement. Where do you draw the line? The easy one would be lead vs no lead at the pump, but that could have other issues. One example is that leaded and unleaded fuels need separate tanks. So now do we need new tanks at all airports to replace 100LL tanks? Remember, this is the government. Logic need not apply.

I'd love to see 100LL, 93 UL, G100, and a host of fuels available at the pumps. I also know that, if I owned the business, I would be highly unlikely to do it unless I had one of those specialized markets in my back yard that would use it so I could make money.

 

[flyingron]

Most of the 100LL avgas is consumed by those who require it (i.e., can not run on lower octane stuff). Continental has evaluated just about every alternative fuel that has been proposed. They see no great catastrophe coming. Even the stuff that is of a lesser octane will work with slightly reduced power. They also claim that their engines are conservatively rated so they believe that they can still make the "RATED" HP even on the lower octane fuel (even if it is less performance that what you're actually getting now).

 

[Geico266]

The difference is modern cars have pressurized fuel tanks and fuel injection supply pressure is much higher than the old carb fuel delivery. In a boat or airplane, vapor lock issues are unchanged whether it's 1963 or 2013

Vapor lock is caused when there is a vaccum. This is why many experimentals have now been designed with the electric fuel pump in the wing root area, if not inside the tank. This eliminates the chance for VL because the entire fuel system is pressurized. A lot of experimental systems now have return lines that while maintaining fuel pressure allow cool fuel to flow trough the system.

Many experimentals burn mogas, and have for tens of thousands of hours with no problems.
Some I know burn ethanol blended fuels.

If vapor lock was such a huge problem we would see a much larger problem, and Peterson would be out of business.

 

[Geico266]

One thing unleaded AvGas will require is a fuel stabilizer, as AvGas sits in tanks a LOT longer than mogas. A truck full of mogas injecting something like StaBil would be a good thing. And some other type of additive reducing vapor lock issues.

This is the bigger issue with mogas. After 30 days the octane begins to drop, and the fuel degrades.

 

[Ted]

Most of the 100LL avgas is consumed by those who require it (i.e., can not run on lower octane stuff). Continental has evaluated just about every alternative fuel that has been proposed. They see no great catastrophe coming. Even the stuff that is of a lesser octane will work with slightly reduced power. They also claim that their engines are conservatively rated so they believe that they can still make the "RATED" HP even on the lower octane fuel (even if it is less performance that what you're actually getting now).

As I understand it, Continental has been pushing this agenda for years to support their 94UL fuel and look good. Basically, they're trying to win the turbo Cirrus market away from GAMI. Unfortunately, it's not realistic. Reduced power will either ground the legacy fleet or result in a certification nightmare of needing to redo performance charts, reduce gross weights, etc.

When you get to Navajos, Dukes, 421s, there really isn't much margin at rated power to reduce your fuel's anti-knock properties. Your cruise points that were good before may now have detonation concerns, requiring limits on leaning that weren't there before. Unless you can show equivalncy, for certified aircraft you're looking at redoing very costly detonation testing on a number of aircraft.

I've not been impressed with Continental's position in this regard.

 

[Alexb2000]

Issues I have so far in the conversation:

1. GAMI or Swift will cost at least 10% more than 100LL, that will force commercial operators to turbines if they are not there already.

2. Some type of universal replacement authorization will have to be done so that each and every aircraft doesn't require an STC. Sounds Hard, REAL hard.

3. As Ted mentioned the 100LL infrastructure may not be able to be reused because of lead contamination. That will be super crazy expensive. How many small airports would have to come up with a couple of hundred grand to make this change???

Lycoming still doesn't even allow LOP operations. The notion that all of the above will get done in my lifetime is just funny.

 

[Ted]

Issues I have so far in the conversation:

1. GAMI or Swift will cost at least 10% more than 100LL, that will force commercial operators to turbines if they are not there already.

2. Some type of universal replacement authorization will have to be done so that each and every aircraft doesn't require an STC. Sounds Hard, REAL hard.

3. As Ted mentioned the 100LL infrastructure may not be able to be reused because of lead contamination. That will be super crazy expensive. How many small airports would have to come up with a couple of hundred grand to make this change???

Lycoming still doesn't even allow LOP operations. The notion that all of the above will get done in my lifetime is just funny.

I'm not sure how many operators would switch to turbines who aren't there already, but there is an argument in certain realms that a Cheyenne is cheaper to operate per mile than a Navajo. My numbers don't agree with that, but I might be missing something. That could also change if 100LL continues to rise. I think most likely we'd see those operators jumping at diesels, which many might do anyway. Count me in on that.

The universal switch isn't as hard as it sounds, it's more that nobody has the guts to go forward and do it. Same with dealing with the lead contamination.

As far as Lycoming and LOP, well, the only guy who had the guts and knowledge to change that doesn't work there anymore...

Thing is, fuel is still less than half my total cost on the 310. So while I would love to spend less on fuel, I'd rather reduce my MX costs (insurance and hangar end up being more or less fixed). That's easier to do in the form of owner-assisted annuals, doing what preventative MX I can, etc. And it's worked, we've managed some significant savings.