As I’ve said, I DON’T NEED 100 octane in my aircraft.
Unleaded no-alcohol MoGas works for me and I have an STC already from the EAA.
Perhaps the easy economical solution is too reasonable? ( ͡° ͜ʖ ͡°)
As far as I know there are two FBOs selling Swift UL94. Both are located in the great lakes region. It is the same price as 100LL. AirNav had a comment regarding poor availability of UL94 at one of them which does not inspire confidence.
The easy, economical solution would have been to have less ridiculous certification standards and to make robbing manufacturers using legal chicanery punishable by imprisonment. Alternatives would doubtless have been presented decades ago.
You can have your not so economical mogas solution as soon as you pony up for a money losing pump everywhere you want to go. No whining about the cost of disposal for all the gallons that go bad because there isn’t enough demand.
2 replies
I don’t think it’s the certification standards, really. Yeah, they were a little outdated in some ways, but they weren’t the primary impediment to so much of GA. I don’t even think it’s the requirements for production under Part 21 (which, don’t get me wrong, are still a pain).
Rather, I think the biggest problem is the requirement that private, non-commercial owner-operators of light airplanes must maintain their aircraft in strict conformance to approved type design over the entire life of the aircraft. Nearest I can figure, that came in because either (a) the FAA figured they needed standards for commercial aircraft, just made one set of “one size fits all” standard, and then has refused to change things on the basis of “we only have one set of rules so there can only be one set of rules”, or (b) they figure that every airplane could theoretically be used commercially, and therefore all airplanes need to be conformed at all times just in case. Either way, it’s my belief that the vast majority of these owner-operators do not find this requirement to always be in strict conformance to approved type design to be a major benefit to them, and would be perfectly happy to convert their airplane to another category that frees them from that requirement–even if it’s a permanent one-way conversion (the FAA thinks otherwise, but I think the market would value such aircraft more).
The FAA itself (in the Par 23 ARC report that eventually led to the Part 23 update) even realized this and proposed that older GA airplanes be released from that requirement (look up “primary non-commercial”) and more or less be treated like homebuilts. Unfortunately, the rest of the FAA has been slow to follow suit. I’m holding out hope that this MOSAIC thing eventually leads us down this path.
Yep, modified Tomahawk engine requires 100 octane fuel per that STC.
The Aerostar I fly needs 100 octane. Reducing the performance of the engine so it can run on lower grade of fuel is not an option on a piston twin. What little single engine performance there is now would go away altogether.
I will save my $100 for a veggie burger at 6B6. I feel their pain trying to start a new capital intensive distribution system is a daunting task. Mean while I will take the instant gratification and a great burger.
The Swift web site FAQ states the following:
“Will I need a separate tank at my airport for your 100-octane avgas to fully replace 100LL?
No, not according to our current Swift Fuels deployment plan. Our 100-octane unleaded avgas will be fully commingable with 100LL. This means that it can be stored in the same airport tank as 100LL and commingled into the aircraft fuel tanks with 100LL at any ratio. Our avgas deployment plan anticipates that all Swift Fuels products can work effectively with 100LL.”
Nonetheless, since use of Swift fuel requires an STC mixing the two in an airport tank will automatically exclude use of that fuel by any aircraft not having the associated STC. The tank will also therefore need to be clearly signed as “not” being 100LL.
Personally I’d rather see Jet-A replace 100LL. Continental and Austro make diesel engines that burn only 5-6 gph. The DA-62 twin burns less than singles, and is faster. All new airplanes could be diesel.
Obviously the current fleet is limited to gasoline, but with STCs to replace the gas engines with diesel as they reach TBO, we can gradually phase them out.
You have to pay for an STC because the FAA won’t let you change fuels without it. Until they approve a new fuel through the PAFI program.
Frankly there isn’t a replacement fuel even close to the composition that will be necessary for use as a ‘drop-in replacement’ for all aircraft/helicopters in all operating conditions globally… People need to stop fixating on the narrow range of operations/types (fixed and rotary) that seem to be mentioned over and over and over with some key important combinations of engine type/operating environment/use, being overlooked. I predict that we are looking at least until 2030 before a suitable fuel is formulated and PROPERLY AND FULLY TESTED IN ALL CIRCUMSTANCES and in ALL possibly engine/airframe combinations in a robust way, as this is more critical than most people realise…
3 replies
Which operations are being overlooked? What additional tests would you require?
There already is, and it has already gone through 10 years of testing. It’s called G100UL.
For those who have opinions, questions, gut-feelings and what-not about G100UL, GAMI has published an FAQ that provides many answers:
https://gami.com/g100ul/GAMI_Q_and_A.pdf
Thinking about it some more … I have a GREAT idea. Why not go back to 80/87 red stuff for those airplanes that can use it. The amount of lead that was in that fuel was less than a quarter of what’s in 100LL. That’d lessen the impact of lead emissions. (Not that I believe it’s an issue at all).
It would appear that we already have a drop in replacement with G100UL for essentially all aircraft that need high octane. But lets take another approach. Various government regulatory agencies have systematically outlawed or otherwise terminated the use of certain industry standard engines such as two-cycle Detroit diesels, most two stroke gasoline engines, most non-tier 4 diesel engines, and mandated alcohol blended fuels that are precluded for use in various engines including many marine engines. So as with other industries why not just say too bad, replace with a compliant power plant or quit using it. I am sure there are many countries where such restrictions do not apply where aircraft are in demand. Just one more example of how aviation should move forward like other entities have been forced to do.
1 reply
Correction: SE01966WI
There’s a very good reason why the EAGLE initiative is proceeding… and it’s technically based and not at all political. One day you’ll no doubt see why the process is as it is. There is NO proven ‘drop in’ replacement available at this stage.
This is a long way from resolved, and people need to stop focusing on the ‘easy cases’ because there are some very ‘hard cases’ (engine/airframe/operational conditions) that are the ones that are making a proper ‘drop-in’ safe fuel that doesn’t have potentially disastrous engine durability outcomes, a real big challenge.
I believe that it’s unwise to claim or believe that any of the current unleaded offerings will work in all operational circumstances in all machines in the global fleet (this isn’t just a USA thing you know). It’s far more complex than almost everybody understands! I have around 100,000 hours REAL WORLD ‘in the air’ testing data from the past 5 years (inc 2000+ destroyed cylinders - and I’m NOT in the USA) and which the cause of their failure would mean that your optimism on ANY of the unleaded proposals so far would be questionable to say the least. Of course my data isn’t going to be shared here!
au revoir (that means I’ll make no further comments - at all).
1 reply
UL 94 is the real answer but it will take another 10 years before that realization sinks in. Until then we will just deny the solution.
Heh, indeed.
Diesel aircraft engines are not all they’re cracked up to be.
And replacement aircraft engines of modern design suitable to modern fuels would be far cheaper if they were sold in their thousands, rather than the drip-feed of today.
So perhaps what is really missing isn’t a drop-in fuel replacement, but a drop-in engine replacement!
But of course, there are many that believe we will still be running O-540s 200 years from now…
I was at George’s Airventure 2022 forum. He showed up late saying that he’d been in a conference where he FINALLY got full STC approval for G100UL. The cynicism and disgust in his voice was evident. How sad that getting the FAA off their proverbial butts often requires congressional direction via laws and the very loud clamor of their customers embarrassing them into action.
I’m about 1/4" from quitting AOPA over its support of EAGLE. How many more times are we gonna have to deal with all this poopus maximus before they wave their magic twangers?
As Einstein said, “Bureaucracy is the death of all any achievement.”
Can you be specific on what major part of aviation is not covered by the drop in replacement G100UL?
No, I’m not… ‘spouting nonsense’ as you rather unscientifically put it.
I’ve been in the technical side of aviation fuel business for over 30 years. It’s several engines (from both major manufacturers) but why would I give a heads up to competitors (and to you)… I won’t, no matter what you ask!!! Go ask GAMI, Shell, Swift etc things such as information on all the various formulations used for the different engine testing and how many different ones they used before providing the final data… and if the same fuel was used for all the engines and all the data released… bet you that they will be not willing to disclose even 5% of what they have there… and given the secrecy around all of this you won’t even be able to judge that!! What I can say is that on the formulations released, there is NO UNLEADED AVGAS SO FAR RELEASED that is proven to be safe in ALL GA engines in ALL operation regimes. If you studied all the formulations carefully and identified the major difference (apart from the obvious absence of lead), between them and avgas that works across the industry, you’d have a chance of identifying where the problem is. Farewell!
