There is a potentially huge problem brewing in the great Avgas UL world. GAMI fuel cannot be used in certified aircraft without buying GAMI’s STC as they have elected not to seek ASTM standards certification, even though they say they meet key aspects of it. This will require owner/operators to buy an expensive STC which is, in essence a license to buy their fuel. GAMI, in cooperation with AVFuel as a distributer, points out that it will be the only game in town for airports using AVFuel as a supplier.
In its Q&A 17, GAMI states, “The STC pricing will be based on engines and horsepower, in a manner similar to the pricing for other fuel STCs that have been available for low octane gasolines.” and Q&A 2, "Current best estimates are that G100UL avgas will cost
60-85 cents/gallon more than 100LL as the fuel leaves the producer’s facility and begins to enter the stream of commerce. " Q&A39, “Because avgas volumes are low relative to jet fuel, and because airport fuel storage tanks have become very expensive to construct and maintain, it is unlikely that any given airport FBO will have multiple unleaded fuels for sale.”
In its other Q&A comments, GAMI says it meets ASTM D910 (100LL) for detonation and D909 for full take off power (equiv to 115/145 Avgas), yet in Q30 asking about ASTM certification GAMI states, “No. GAMI elected to use the existing and approved STC
pathway to obtain approval for our general aviation aircraft and engines to use G100UL avgas”
So, while the bulk of GAMI’s revenue will come from fuel sales profit and will far exceed the $450-$500 STC hit per engine, per airframe this cost is not trivial, especially for a C152 operator and is concern if you don’t have it and need fuel at an FBO that only has the GAMI on field.
Years ago, I bought the Peterson STC for MOGAS at a cost of $1/hp and the EAA’s was just becoming available when 80 went away. GAMI (per the ever pervasive hangar talk rumors) wants double that for its STC.
SwiftFuels to its credit markets its 94UL which meets the old ASTM D910/D910-95A used for 80 octane fuels used in the low compression O-470-R engines and many others. According to an airport I frequent which has SwiftFuel 94UL I am good to go without an STC because of that spec. If I want, I can buy a forever STC from Swift for about $100, but apparently don’t need it to use 94UL in my airframe engine combination.
If GAMI’s fuel is universal as they say it is, why to we need to pay them for the STC/license to buy its fuel at likely a $1-2/gallon more than 100LL and double or triple the cost of Mogas for those of us who can and do use it and can get it?
The FAA should insist on having manufacturers that meet ASTM standards, get their fuels qualified and permit all airframe/engines that qualify to use their fuels.
GAMI’s take if the entire GA fleet needs an STC to get the only fuel available: 150,000 GA aircraft burning gasoline x $450/GAMI STC x 70% of the fleet = ~ $50M and likely more when twins and engine replacements are needed. GAMI’s web site is very quiet on the cost of the STC per airframe/engine combination. GAMI’s competition, if/when it arrives will face a very high barrier even if it does not require an STC, or alternatively we will have to buy the Mogas STC, the GAMI STC, the Swift STC, the UGuess(n…) STC to insure we can legally buy the fuel that will be available on our next stop or restrict ourselves to airports that carry the fuel we have a license to buy. There has to be a better solution that this.
I cannot see how this is a good solution to our fuel issues.