FAA Approves 100R Avgas in Cessna 172s

[toto]

Kind of interesting. FAA has granted one STC for 100R on one Skyhawk engine, but Swift says they’re also pursuing ASTM certification.

This was already mentioned by @hammdo in the recent G100UL thread but might be worth a separate discussion.

I’m excited to see unleaded options on the horizon to eliminate the cloud hanging over piston GA for the past 50 years, but buying UL anything still seems a long way off. Maybe ASTM certification would suddenly make FBOs want to carry this stuff?

https://aviationweek.com/business-aviation/safety-ops-regulation/faa-approves-100r-avgas-cessna-172s

[Pinecone]

Except that Swift has already stated that their 100 UL will not work for a good percentage (15%??) of the GA fleet.

 

[M20S Driver]

From AI (Perplexity) :

Based on the search results provided, it appears that the statement "Swift has already stated that their 100 UL will not work for a good percentage (15%??) of the GA fleet" is not entirely accurate. Let's break down the information available:

Swift Fuels' Unleaded Aviation Gasoline Options

Swift Fuels offers two main unleaded aviation gasoline (avgas) products:

1. Swift UL94: This is a 94-octane unleaded avgas that is compatible with lower-compression, naturally aspirated aircraft engines.
2. Swift 100R: This is a 105-octane (R+M)/2 rated gasoline (100 MON) designed to replace 100LL leaded avgas in all piston aircraft

Compatibility and Availability

1. Swift UL94 is indeed limited in its compatibility, as it's only suitable for low compression, naturally aspirated aircraft engines. This represents less than 85% of the fleet
2. However, Swift 100R (their 100-octane unleaded product) is designed to replace 100LL in all piston aircraft. This suggests a much broader compatibility than the 85% figure mentioned in the query.
3. As of September 2024, Swift Fuels' 100-octane unleaded aviation fuel received its first Supplemental Type Certificate (STC) for use in Cessna 172 R and S models.  This indicates progress in the certification and approval process for wider use.

Distribution and Future Plans

1. Swift has indicated that they will replace their 91/94 distribution with 100UL when it becomes available, suggesting a planned transition to the higher-octane unleaded fuel
2. The company is working on expanding its distribution network, with partnerships like the one with AvFuel mentioned in the search results.

It's important to note that the transition to unleaded avgas is an ongoing process, with multiple companies working on solutions. The exact percentage of the GA fleet that can use Swift's 100-octane unleaded fuel may change as more STCs are granted and more testing is completed.In conclusion, while there are limitations for Swift's lower-octane UL94, their 100-octane product (100R) is designed for broader compatibility across the GA fleet. The statement in the query appears to be mixing information about different Swift fuel products.

[Pinecone]

Swift has stated that their 100 will NOT work in all aircraft in the past year or two.

The statement that it will replace 100LL across the fleet was from 2021.

See many threads on BeechTalk

[toto]

5 minutes ago, Pinecone said:

Swift has stated that their 100 will NOT work in all aircraft in the past year or two.

The statement that it will replace 100LL across the fleet was from 2021.

See many threads on BeechTalk

The Swift FAQ page says

[1980Mooney]

1 hour ago, toto said:

The Swift FAQ page says

Yes Swift says "Swift 100R is a 100-Motor-Octane aviation gasoline designed to fully replace 100LL Leaded Avgas across the entire global piston fleet".

The key words are "designed to" - that doesn't  mean it actually works as "designed" and it certainly has not been proven so.  UL94 did not work "as designed" at the UND flight school fleet.

Swift Fuels’ 100-octane unleaded aviation fuel granted first STC - AOPA

Swift CEO Acosta said to AOPA in the announcement  “We’re following a very similar approach where we approve a certain set of engines and airframes and then we expand from that, just like we did nine years ago with UL94,” D’Acosta said. “It’s exactly the same architected program except that’s it’s for the 100-octane fuel."   Exactly the same...and that worked out really well for the UND Flight School.  Considering that the FAA approval is only for the newest C-172 Skyhawk R's and S's which almost all are found at flight schools, I wonder what flight school will want to risk engine damage for Swift (i.e. UND Ver. 2.0...)

I find it really interesting that after the FAA approval, the stories by AOPA, AviaitonWeek, every aviation publication, that if you go to the Swift Fuels website, there is no mention of the approval or the limited STC.  There is no mention in the "News" tab/drop down and nothing new on the R100 page.  It is almost as if Swift is not proud of the milestone.  I bet that Swift thought that they would get a broad sweeping approval - Instead only one engine on one Cessna model

News — SwiftFuels
 

[toto]

2 hours ago, 1980Mooney said:

I find it really interesting that after the FAA approval, the stories by AOPA, AviaitonWeek, every aviation publication, that if you go to the Swift Fuels website, there is no mention of the approval or the limited STC

They did put it on their FAQ page. It might be as simple as the FAQ being maintained by someone at Swift, and the main site being updated by an outside agency. Dunno 

[Martin S.]

On 10/1/2024 at 3:28 PM, Pinecone said:

Except that Swift has already stated that their 100 UL will not work for a good percentage (15%??) of the GA fleet.

 

Hey Pinecone,

That’s interesting - do you remember where this was stated or do you happen to have a link to an article or video or where Swift mentioned this?

Many thanks,

Martin

[GeeBee]

Apparently, Swift has set up a TSIO-550 on test for 100R

 

https://avweb.com/ownership/swift-confident-its-100r-unleaded-will-be-the-last-fuel-standing/

[Martin S.]

5 minutes ago, GeeBee said:

Apparently, Swift has set up a TSIO-550 on test for 100R

 

https://avweb.com/ownership/swift-confident-its-100r-unleaded-will-be-the-last-fuel-standing/

OK – they mention reaching 75% by the end of 2025, which might be what @Pinecone was referring to. On another note, most M20 IO-360 engines appear to have a relatively high compression ratio of 8.7:1. Does anyone knowleadable see a risk that the 100R might not work for these engines?

[IvanP]

Interesting. What do we know about 100R and its compatibility with various components of the fuel system and airframes? It seems that both GAMI and Swift want they fuel to be the only option for piston aircraft. At least Swift is going through the ASTM standardization process, whereas GAMI is trying to use environut lawfare and flawed STC process to push thier product to market.  

[redbaron1982]

A very important edge that Swift has in this race is that they are already selling 94UL in many airports, their plan is to phase out 94UL and replace it with 100R.

If they manage to get 100R STC´d or somehow approved fleet wide, then they will have a much easier go to market road than GAMI, who is trying to play the role of "shut up, we know what we are doing, you don´t get to ask questions about G100UL, and we are not running our fuel through ASTM or anything similar, because they know nothing about fuels."

[Pinecone]

3 hours ago, IvanP said:

whereas GAMI is trying to use environut lawfare and flawed STC process to push thier product to market.  

You do know that the Swift fuel requires an STC?  What makes theirs not "flawed."

ASTM is not approval.

[IvanP]

5 hours ago, Pinecone said:

You do know that the Swift fuel requires an STC?  What makes theirs not "flawed."

ASTM is not approval.

I am not a fan of the STC process for fuels and I am aware of the STC for 94UL. It clearly acknowledges the known limitations of 94UL. However, the ASTM standard path at least provides some measure of transparency about the fuel which is conspicuously absent from GAMI process. I believe in empirical testing with reproducilbe results. Similarly, I am of the opinion that the markets, rather than court decrees or government mandates, should determine the winner in this race. The approach Swift and GAMI are choosing appear to be quite different. May the best fuel win (could be niether of the two). 

There seems to be growing body of evidence that G100UL has some serious material compatibility issues and, regretably, the purveyor of the fuel chose the path of refusing to acknowledge the issues and diminishing the nature of the problem while stedfastly refusing to subject their product to standardized independent testing. That alone is a giant red flag for me. GAMI should be free to sell their brew to whomever wants to buy it, but the customers should not be forced to buy it.  

[MikeOH]

@IvanP

Well put!

I'd add that what I find 'flawed' in the STC process is the inconsistency of how GAMI was granted a BLANKET STC without providing individual testing data for each engine, airframe, and engine/airframe combination.  I think this may be unprecedented.  What other company has been granted that comprehensive of STC?  It would appear Swift has had to prove each combo; e.g. an STC just for C172R and S models.

Or, look at autopilot STCs, the FAA most certainly won't issue a blanket STC for an entire fleet, let alone ALL aircraft!  No, the analogy is not perfect, but the salient point is that each engine and engine/airframe combo is unique and approval without adequate individual testing seems 'flawed' to my engineering mind.

[Pinecone]

8 hours ago, IvanP said:

I am not a fan of the STC process for fuels and I am aware of the STC for 94UL. It clearly acknowledges the known limitations of 94UL. However, the ASTM standard path at least provides some measure of transparency about the fuel which is conspicuously absent from GAMI process. I believe in empirical testing with reproducilbe results. Similarly, I am of the opinion that the markets, rather than court decrees or government mandates, should determine the winner in this race. The approach Swift and GAMI are choosing appear to be quite different. May the best fuel win (could be niether of the two). 

There seems to be growing body of evidence that G100UL has some serious material compatibility issues and, regretably, the purveyor of the fuel chose the path of refusing to acknowledge the issues and diminishing the nature of the problem while stedfastly refusing to subject their product to standardized independent testing. That alone is a giant red flag for me. GAMI should be free to sell their brew to whomever wants to buy it, but the customers should not be forced to buy it.  

100R also requires an STC.

I agree it should be market driven.

If you want independent testing of G100UL, buy some and sent it to a lab.  But then what are you going to do with results?

[Pinecone]

8 hours ago, MikeOH said:

@IvanP

It would appear Swift has had to prove each combo; e.g. an STC just for C172R and S models.

Swift decided to STC those models to start.

So, how is going to PAY for all that testing?  Every airframe and engine????  

Maybe for the common aircraft, but more obscure models would never be done.  I have  CAP-10.  Only 22 in the US.  So, I just I would just have to park it.

[Fly Boomer]

8 hours ago, MikeOH said:

I'd add that what I find 'flawed' in the STC process is the inconsistency of how GAMI was granted a BLANKET STC without providing individual testing data for each engine, airframe, and engine/airframe combination.

I think there are well over 1,000 airframe type certs.  Testing every combination means that most will never be tested.

[EricJ]

STCs for fuels that are ultimately compliant to an ASTM standard will likely become a non-issue, which I'm guessing is likely the intent.   In other words, until the ASTM standard is finalized the fuels can be used via the STC.    Once the ASTM compliance is in place and established, then I don't know what would stop somebody from just pointing at their TCDS and saying they're using a compliant fuel if the fuel is marked as 100 grade aviation fuel.    I suspect this is the overall plan for those pursuing ASTM standardization.   That seems to be a big reason to pursue that.

[IvanP]

2 hours ago, Pinecone said:

 

Maybe for the common aircraft, but more obscure models would never be done.  I have  CAP-10.  Only 22 in the US.  So, I just I would just have to park it.

You can always put G100UL in it and see what happens. After all, it is a "commercially available drop-in replacement for 100LL" that does not cause any harm to "properly" maintained engines and/or airframes, or so would George lead us to believe according to his many statements and presentations  . 

[Paul Thomas]

2 hours ago, Pinecone said:

Swift decided to STC those models to start.

So, how is going to PAY for all that testing?  Every airframe and engine????  

Maybe for the common aircraft, but more obscure models would never be done.  I have  CAP-10.  Only 22 in the US.  So, I just I would just have to park it.

Isn't that how the mogas STC work? Why has GAMI been treated differently?

[IvanP]

25 minutes ago, Paul Thomas said:

Isn't that how the mogas STC work? Why has GAMI been treated differently?

My guess is that there may have been some political arm twisting to "protect the children" at all cost and possible "donations" to various parties involved in the process of getting expedited blanket STC for G100UL without adequate testing and scrutiny. As always, if we follow the money, the truth will probably come out at some point. After all, we have the best politicians money can buy. 

 - Sarcasm Off -

[MikeOH]

2 hours ago, Paul Thomas said:

Isn't that how the mogas STC work? Why has GAMI been treated differently?

Exactly my earlier point: it sure looks like a double standard...GAMI gets the 'blanket', others need to go model by model.

I think @EricJ is right: once a fuel meets an ASTM standard for 100, then the problem is solved; it meets the TCDS.

[redbaron1982]

1 minute ago, MikeOH said:

Exactly my earlier point: it sure looks like a double standard...GAMI gets the 'blanket', others need to go model by model.

I think @EricJ is right: once a fuel meets an ASTM standard for 100, then the problem is solved; it meets the TCDS.

But a new standard would need to be defined, right? the TCDS calls for 100LL, which in turn have a minimum TEL content. So you cannot have UL meet the 100LL standard.

[MikeOH]

1 hour ago, IvanP said:

My guess is that there may have been some political arm twisting to "protect the children" at all cost and possible "donations" to various parties involved in the process of getting expedited blanket STC for G100UL without adequate testing and scrutiny. As always, if we follow the money, the truth will probably come out at some point. After all, we have the best politicians money can buy. 

 - Sarcasm Off -

BINGO! I don't think you're being sarcastic, at all.  My thought is the FAA is under pressure from many groups, e.g. EPA, to 'solve' the 'lead in the air' problem...GAMI was the 'low hanging fruit' and the 'blanket STC' was the result.