Unleaded Avgas

[TXFlyGuy]

So...where do we stand on having a reliable source of high octane (93 rating or more), available for us GA types out flying our high performance RV's?

I just read that we are now in Phase II of testing. How many phases will there be? 3, 4, more?

What is the holdup, and what parameters are being looked at? Can engines that are currently burning 100LL not be safely run on lead and alcohol free 93 octane?

Here is the answer. So why is it not available right now? The industry has signed off on this, and the UL105 fuel as well.

https://swiftfuels.com/fuel/unleaded-ul94-avgas/

[jnmeade]

It's for sale in Wisconsin, Indiana and a few other airports. Get your airport to call them up and get it installed. Here's the map from Swift's web site.

https://swiftfuels.com/ul94-map/

[tspear]

Originally Posted by jnmeade

It's for sale in Wisconsin, Indiana and a few other airports. Get your airport to call them up and get it installed. Here's the map from Swift's web site.

https://swiftfuels.com/ul94-map/

Note: That is not the same stuff going through PAFI testing.

Tim

[tspear]

Originally Posted by TXFlyGuy

So...where do we stand on having a reliable source of high octane (93 rating or more), available for us GA types out flying our high performance RV's?

I just read that we are now in Phase II of testing. How many phases will there be? 3, 4, more?

What is the holdup, and what parameters are being looked at? Can engines that are currently burning 100LL not be safely run on lead and alcohol free 93 octane?

Here is the answer. So why is it not available right now? The industry has signed off on this, and the UL105 fuel as well.

https://swiftfuels.com/fuel/unleaded-ul94-avgas/

No, the industry has not signed off on it.
By number, most engines could run on 91UL. The problem is that the engines which cannot run on 91UL with out detonation and other issues are the most prolific consumers of avgas. Depends on who surveys you use, but the numbers I have seen are between 60-80% of the avgas consumed in the USA is by planes which cannot run on 91UL or any related variety.
Basically this is the turbo charged engines and engines with a compression ratio around 8.5 tend to have issues.

As for status, I stopped paying attention. GAMI is still pushing forward with the STC for the G100 solution, I think two others dropped out of the PAFI solution (not sure why). Part of the reason I hope for a diesel/JetA solution.

Tim

[TXFlyGuy]

Well, how about UL102? It appears that most of the OEM types have signed off on the UL94, with the UL102 in the works. But...the FAA is involved. And this is adding years to the approval.

Like when pilots were burning auto fuel in their Lycomings, because the engine ran better as it was designed for 80 Octane. Many did this well before the EAA got an STC for the use of auto gas.

https://swiftfuels.com/fuel/unleaded-ul102-avgas/

Only Unleaded 100+ Octane Avgas Approved by ASTM International (D7719)

UL102 is the first and only unleaded high-octane avgas to have an ASTM Production Specification approved for avgas - ASTM D7719, Standard Specification for High Aromatic Content Unleaded Hydrocarbon Aviation Gasoline. This approval was earned through cross-industry evaluation by a 100+ member ASTM subcommittee, including representatives from industry advocacy groups, regulatory agencies, engine/airframe OEM's, fuel producers, testing laboratories, and more.

[tspear]

Originally Posted by TXFlyGuy

Well, how about UL102? It appears that most of the OEM types have signed off on the UL94, with the UL102 in the works. But...the FAA is involved. And this is adding years to the approval.

Like when pilots were burning auto fuel in their Lycomings, because the engine ran better as it was designed for 80 Octane. Many did this well before the EAA got an STC for the use of auto gas.

https://swiftfuels.com/fuel/unleaded-ul102-avgas/

Only Unleaded 100+ Octane Avgas Approved by ASTM International (D7719)

UL102 is the first and only unleaded high-octane avgas to have an ASTM Production Specification approved for avgas - ASTM D7719, Standard Specification for High Aromatic Content Unleaded Hydrocarbon Aviation Gasoline. This approval was earned through cross-industry evaluation by a 100+ member ASTM subcommittee, including representatives from industry advocacy groups, regulatory agencies, engine/airframe OEM's, fuel producers, testing laboratories, and more.

All Swift did was take the formula and pay the fee to Apply to ATSM to create a standard based on their specific formula. The FAA standard formula is ASTM D910-17.
Swift can either match ASTM D910-17; or pursue some avenue with the FAA to get D7719 approved as an alternate. Currently there are two routes, via an AML STC or the PAFI program.

As for the old Lycoming/Continental running on 80 octane gas; they tend to be lower compression engines; and if they had enough planes flying would likely have been included in the auto STC since it was formulated in a manor similar to an AML (this is per reading the history of the Peterson STC on the net).

So it comes back to volume, you are either concerned only about the majority of planes, or the majority of the avgas consumers. If you care about the major consumers of avgas, then all the other planes are automatically taken care of.

Tim

[rv7charlie]

To OP,

You didn't specify the a/c or engine. You might well not need 100 octane. And it's been a while since I've been back and forth with homebuilt testing, but IIRC, There's phase 1 (testing), and phase 2, normal ops *for an experimental*. I'm guessing that the FAA won't call it normal operation because experimentals do have (minor) restrictions on where they can be operated, unlike cert. a/c.

[TXFlyGuy]

Originally Posted by rv7charlie

To OP,

You didn't specify the a/c or engine. You might well not need 100 octane. And it's been a while since I've been back and forth with homebuilt testing, but IIRC, There's phase 1 (testing), and phase 2, normal ops *for an experimental*. I'm guessing that the FAA won't call it normal operation because experimentals do have (minor) restrictions on where they can be operated, unlike cert. a/c.

The post is general in nature, but let's say for argument it is geared to those RV's with non conventional engines, such as Chevy or (fill in the blank) V8's. Engines that would normally run on 92/93 Octane unleaded auto gas.

It seems like this has been ongoing for years, and we are curious as to when a final result, i.e., fuel will be available for the mass market.

And, at what cost?

I see nothing but good coming from a UL fuel. Cleaner engines, for starters.

[BrianDC]

Originally Posted by rv7charlie

To OP,

You didn't specify the a/c or engine. You might well not need 100 octane. And it's been a while since I've been back and forth with homebuilt testing, but IIRC, There's phase 1 (testing), and phase 2, normal ops *for an experimental*. I'm guessing that the FAA won't call it normal operation because experimentals do have (minor) restrictions on where they can be operated, unlike cert. a/c.

I believe the OP was referring to the stages the FAA is going through on the Piston Aviation Fuel Initiative (PAFI). Not the testing of his specific RV build.
Phase 1 of the PAFI was lab testing and trying to narrow the field to a just a handful of formulas.
Phase 2 is testing in actual engines / aircraft.

Looks like they "should" have final approval and recommendations by the end of the year?

[TXFlyGuy]

Originally Posted by BrianDC

I believe the OP was referring to the stages the FAA is going through on the Piston Aviation Fuel Initiative (PAFI). Not the testing of his specific RV build.
Phase 1 of the PAFI was lab testing and trying to narrow the field to a just a handful of formulas.
Phase 2 is testing in actual engines / aircraft.

Looks like they "should" have final approval and recommendations by the end of the year?

Thank you for helping to clarify the intent. Yes, the multiple stages, and time required.
How many hours do you have to put on an engine with the new fuel before you certify it safe?

Who ultimately makes that decision...FAA? The manufacturers? Oil companies?