FAA To Approve Use Of 91UL Fuel In Two-Thirds Of Piston Fleet

FPK1

FPK1

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Another AVgas replacement is coming for more engines... But pretty vague at this time:

The FAA will issue a fleet authorization this year that will allow more than two-thirds of the gasoline piston fleet to operate on 91UL avgas. In a news conference held to update progress on the development of an unleaded high-octane replacement for 100UL, Lirio Liu, the head of certification for the FAA, said the agency plans to issue the blanket approval as part of the initiative to get rid of lead in avgas. “We expect approximately about 68 percent of the general aviation fleet will be able to use the UL91.”

In addition to reducing lead emissions from piston aircraft, the fleet authorization for UL91 will give a glimpse of a lead-free future for GA aircraft. “That will facilitate broader use and experience with the transition,” Liu said.

Russ Niles
http://www.avweb.com
 
Does this mean no STC needed?
 
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Why would an FBO want to sell 91UL instead of G100UL? 91UL might get approved for 2/3 of the fleet, but the 1/3 of the fleet that can't use it consumes more gas. I can't believe any airport is going to sell both 91UL and G100UL, so if their choice is to sell limited quantities (91UL) or to sell a fuel (G100UL) that all piston engine airplanes can use, the decision will be obvious.

The single-fuel solution is how we arrived at 100LL back in the day, as it has universal use for piston planes. The logic behind that decision has not changed.

This smacks of EAGLE trying to be relevant and justify existence.
 
In the midst of a transition - lets come out with 1000 different blends rather than figuring out the best one and see what happens with misfueling
 
Hmm, for G100UL, FAA said it was not within their power to grant a fleet wide approval.

Under what regulation/law would they do so?
 
Pinecone said:
Hmm, for G100UL, FAA said it was not within their power to grant a fleet wide approval.

Under what regulation/law would they do so?
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Well, they sorta did, by approving a fleet-wide STC. That's the route that GAMI chose, and GAMI owns the rights to the fuel.

I know that G100UL does not meet the existing fuel specification, so I think that an STC was the only available means for approval. Perhaps 91UL does meet the specification, and thus could be approved under that spec, but the article doesn't say that so I don't really know.
 
Half Fast said:
I can't believe any airport is going to sell both 91UL and G100UL
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This will be the biggest barrier to widespread adoption. Most small airports don't have two fuel farms for avgas anymore. In the old days, you could get 80 or 100 octane avgas at many airfields, but when 100LL became available, most airports dumped the lower octane fuels like a hot rock. G100UL or its equivalent is the only widely practical solution to removing lead from aviation fuel. An airport that only sells 91UL will be in world of hurt with many of their based aircraft owners, and the potential for misfueling will be greatly increased.
 
Half Fast said:
Well, they sorta did, by approving a fleet-wide STC. That's the route that GAMI chose, and GAMI owns the rights to the fuel.

I know that G100UL does not meet the existing fuel specification, so I think that an STC was the only available means for approval. Perhaps 91UL does meet the specification, and thus could be approved under that spec, but the article doesn't say that so I don't really know.
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91UL is basically 100LL without the TEL additive, so it should meet the fuel specifications for aircraft that do not require 100 octane fuel. G100UL took the (necessary) approach of dispensing with the existing fuel specification in order to achieve the desired result of serving the entire piston fleet.
 
IMHO it's not complicated. Just sell 100 UL. Forget forming a committee to come up with a solution in search of a problem just so people can get paid to do power point kabuki dancing.
 
Imagine the uproar if the FAA declined to approve a viable alternative to an $TC for [sic] 'two-thirds of the gasoline piston fleet'. Let the market decide.

Nauga,
and insistence on inconsistence
 
nauga said:
Imagine the uproar if the FAA declined to approve a viable alternative to an $TC for [sic] 'two-thirds of the gasoline piston fleet'. Let the market decide.

Nauga,
and insistence on inconsistence
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The FAA is obligated to approve it if it meets spec, but I can’t see it going anywhere.
 
Dana said:
Only if it's significantly cheaper than G100UL.
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No, only if the profit available to FBOs is significantly greater than that for GAMI gas, and that will take quantity into account. Significantly more GAMI gas can be sold than 91UL.
 
NealRomeoGolf said:
2/3 of the fleet means nothing when 80% of avgas consumption is in the 1/3 not covered.

I made that stat up but I think it's true-ish.

I'm in the 1/3.
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Beats me what the right number is (I heard somewhere that 1/3 consumes 2/3 and vice versa), but it's the right general idea. I can't see an airport choosing to sell 91UL over G100UL, and I can't seen an airport selling both.

Mostly, I think the FAA needs to approve fuels that are approvable and otherwise get out of the way. If EAGLE is to be useful, the best thing it could do would be help get fuels to the market. We now have two UL fuels that my plane can drink but there's no place I can buy one of them.
 
Half Fast said:
Beats me what the right number is (I heard somewhere that 1/3 consumes 2/3 and vice versa), but it's the right general idea. I can't see an airport choosing to sell 91UL over G100UL, and I can't seen an airport selling both.
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There are airports today (admittedly not many) that sell both 100LL and 94UL, or 100LL and mogas. These are mostly smaller airports where probably most of the traffic doesn't require 100.

There are still quite a few airports that still have the old 80 octane tank sitting unused.
 
If I had a small county airport that was able to sell the 91UL at a discount, I think I would be quite busy with with cross country and nearby local pilots looking to save a buck. Not every small airport needs to carry the same fuel. I fly 40 miles to buy cheaper fuel and a place to exercise my plane and pilot skills.
 
Half Fast said:
Why would an FBO want to sell 91UL instead of G100UL? 91UL might get approved for 2/3 of the fleet, but the 1/3 of the fleet that can't use it consumes more gas. I can't believe any airport is going to sell both 91UL and G100UL, so if their choice is to sell limited quantities (91UL) or to sell a fuel (G100UL) that all piston engine airplanes can use, the decision will be obvious.

The single-fuel solution is how we arrived at 100LL back in the day, as it has universal use for piston planes. The logic behind that decision has not changed.

This smacks of EAGLE trying to be relevant and justify existence.
Click to expand...

I believe the market will make the decision when the options become available and there is wholesale pricing in place. The 100LL replacement has been reported to carry a $1 premium over 100LL.

The FAA will likely have AIP grants for fuel delivery upgrades.
 
chemgeek said:
91UL is basically 100LL without the TEL additive, so it should meet the fuel specifications for aircraft that do not require 100 octane fuel. G100UL took the (necessary) approach of dispensing with the existing fuel specification in order to achieve the desired result of serving the entire piston fleet.
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I’ve now heard both of these:

100LL - Lead = 94UL and 100LL - Lead = 91UL

which is true?
 
NealRomeoGolf said:
2/3 of the fleet means nothing when 80% of avgas consumption is in the 1/3 not covered.

I made that stat up but I think it's true-ish.

I'm in the 1/3.
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This seems to be an oft repeated if not growing proportion over the last 20 years. Is there any current data or any data to support? It seems to be a topic that pits the folks who need 100 against the ones who don’t for obvious reasons. I’d just like to see the data.
 
focal_plane said:
This seems to be an oft repeated if not growing proportion over the last 20 years. Is there any current data or any data to support? It seems to be a topic that pits the folks who need 100 against the ones who don’t for obvious reasons. I’d just like to see the data.
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I would guess GAMI has the data or PAFI did. Pretty sure GAMI is who has repeated the status they've talked about G100UL.
 
I just don't get it.
Does anyone here own a piston powered plane that that can't and use get the auto fuel STC?
High (94) octane with no ethanol is still cheaper than Avgas and WAY cheaper than GAMI.
 
Shepherd said:
I just don't get it.
Does anyone here own a piston powered plane that that can't and use get the auto fuel STC?
High (94) octane with no ethanol is still cheaper than Avgas and WAY cheaper than GAMI.
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My Beech can't get an autogas STC.
 
I’ve only seen 100LL and Jet-A fuel at most airports that I fly to. Where are all of these other variants? I don’t want to be finding special airports to get a certain type of fuel, forget mixing the wrong fuel, how about fuel exhaustion trying to make it to “the” airport.
 
..."I think EAGLE and the alphabets are making a mistake by the not-so-subtle dissing of the STC approval method and, by association, G100UL. The fuel is out there. It has been through one of the most rigorous testing programs ever overseen by the Wichita ACO. It is, by all appearances, a suitable fuel for a 100LL replacement. It’s true that it doesn’t have to be and might not be the only one. Perhaps Phillips or Lyondell—or both—will develop better fuels that are less expensive to produce and sell. So be it. They should go forward with the support of the industry and GAMI deserves nothing less, not watery excuses about lack of testing and not knowing what’s in the fuel."

Paul Bertorelli
https://www.avweb.com/uncategorized/eagle-and-gami-not-a-transparent-process/
 
Shepherd said:
I just don't get it.
Does anyone here own a piston powered plane that that can't and use get the auto fuel STC?
High (94) octane with no ethanol is still cheaper than Avgas and WAY cheaper than GAMI.
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As far as I know no STC for my Lance. I considered it when I had the Archer but it required fuel system modifications and I can probably count on one hand he number of times I’ve been to a field that had mogas available so it wasn’t worth it.

Now, how many of us could put it in our tanks and be just fine is an entirely different question but that’s now how the certified aircraft world works.
 
Wow. I didn't realize how many types can't use the auto fuel STC.
Thanks for the edgamacation.
 
Ed Haywood said:
I do. AEIO-360 H1A
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Note that a fuel can be approved for an engine but not approved for a particular plane, due to issues with the fuel storage and delivery system. The table in this document shows that my O360 can run on anything this side of Jack Daniels, but mogas is not approved for my Beech (I believe there was a vaporization problem).

EDITED TO ADD:
Just found this - “The airframes we have flight tested which failed the test include the Navion, Musketeer, Piper Apache PA-23-235, 7KCAB, Mooney M-20-C, Piper PA-24 250 Comanche & the Avcon converted 180 hp Cessna 172. Generally speaking, any pump fed airplane not already on the approved list is incapable of passing the flight tests unless substantial modifications are made.”
 
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Half Fast said:
Note that a fuel can be approved for an engine but not approved for a particular plane, due to issues with the fuel storage and delivery system. The table in this document shows that my O360 can run on anything this side of Jack Daniels, but mogas is not approved for my Beech (I believe there was a vaporization problem).

EDITED TO ADD:
Just found this - “The airframes we have flight tested which failed the test include the Navion, Musketeer, Piper Apache PA-23-235, 7KCAB, Mooney M-20-C, Piper PA-24 250 Comanche & the Avcon converted 180 hp Cessna 172. Generally speaking, any pump fed airplane not already on the approved list is incapable of passing the flight tests unless substantial modifications are made.”
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Wait, were we talking about unleaded avgas? Or the Petersen autogas STC?
 
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