MichaLSA wrote:
That is NOT an STC! That is only an airlaw clearance that nobody will get fined using UL91 in the engines in question.
It does not need an STC, if the engine maker allows it, then all warranties and liabilities are valid.
If I were to buy a plane tomorrow, Lycoming’s SI1070 is definitely in the equation.
Buy a TB20 
The problem is that, as has been much discussed, almost no airfield will carry both 100LL and 91UL. Or actually any two fuels unless one is Jet-A1. TOTAL tried to split the market (cynically, because it would have destroyed a big chunk of 100LL-only burners, and stupidly, because their 91UL was not cheaper) and failed, despite giving away bowsers for free.
So until a completely universal “100UL” arrives, there will be nothing.
MichaLSA wrote:
That is NOT an STC! That is only an airlaw clearance that nobody will get fined using UL91 in the engines in question. The CS-STAN approach to enable use of UL91/UL94 does have some negative impact, as it does not cover any liability of EASA for damages caused, or better any maintenance organization and engine overhaul station is out of liability, because it remains ‘use of not by vendor approved fuel’
The Standard Change is not an approval to use UL91 or 91/96UL with engines. It is an approval to use those fuels in an aircraft which 1) was previously approved for AVGAS (or MOGAS) and 2) has an engine that has an explicit approval for these fuels from the engine manufacturer.
Peter wrote:
The problem is that, as has been much discussed, almost no airfield will carry both 100LL and 91UL.
For those airplanes which can use UL91 such as mine that is not a problem, even though I’d prefer UL91 to be available where I fly, as it is definitly the better fuel for the engine, which is very prone to spark plug fouling.
Where UL91 is not available, mostly 100LL is. I can use both, so fine. Once 100LL is banned or no longer commercially viable, I guess most will change to UL91.
Actually, looking at some places here, there are a few which have a choice. e.g. Bressaucourt (LSZQ) has all 3, 100LL, UL91 and Jet A1. UL91 is about 10 cents per liter cheaper. LSPL/Langenthal also has both UL91 and 100LL, so has Bern (LSZB), Sion (LSGS) and Yverdon (LSGY) and several more, these are just the ones I found. Generally, UL91 here is approximately 10-15 CH cents cheaper than 100LL, which still for a 100 l fuel tank is a noteworthy difference.
I understand that availability for UL91 in the UK is also on the rise, I only found one reference that about 15 airfields offered it in 2018, in the mean time I guess there should be more.
Some Youtubers (including Paul B) take on leaded aviation fuels. Rather interesting and to the point.
Nothing new in these Avweb videos, just a recap of the history.
And nothing that hints towards an immiment end of 100LL.
boscomantico wrote:
And nothing that hints towards an immiment end of 100LL.
Exactly. It’s all just dumb and (slightly) ridiculous That’s the whole story in a nutshell.
I am always surprised how stupid these discussions tend to go.
Yes, Lead in the air is no good thing, as any pollution.
Yes, it does poison you if there is too much.
No, we are not talking big leverage when talking GA.
One thing which really bothers me is this contemporary NIMBY thinking. I do prefer one2one feedback for anything we do in life. Maybe even taking the exhaust exit of combustion engines inside our cars should be one of the best actions to reduce pollution – if you breathe it, you do something about it. Instead we do electrical cars, where the pollution is not less, but simply elsewhere, in Kongo for example.
Back to topic.
How many pilots suffer from Lead poisoning? We are right next to that nasty stuff and I am not aware of any significant number of pilots dying from Lead, or am I mistaken? Further on, learning from history also means learning from unleaded fuel: on continental Europe they replaced Lead with Benzene (saying is due to translation error) which is a nasty Polycyclic Aromatic Hydrocarbon PAH. Lead poisons you and you suffer from direct reaction (1:1 feedback) and PAH does not poison you directly, but alters your physiology in a subtle and not well understood way (risk of not well understood long term effects). As said before, I prefer the direct way, because it is manageable by everybody on their own. Trading direct threads for hidden risks is a bad thing to do as part of the evolution.
I seem to remember the whole thing about lead started with reports, not of people dying but of people especially kids suffering brain problems due to lead poisoning. Whether it is true or.not.I have no idea. But it did lead.to lead toys being banned followed by lead in paint and the in petrol. Now this way round may well have been because the fuel and motoring lobby was a lot more powerful than the kids toy lobby.
Whatever, we still have 100LL but it is a small market and getting smaller.
The question is whether the public attitude to leaded fuels will cause the demise of Avgas.
Or will, and IMO the most likely scenario be that Avgas will become commercially unviable.
We only have to look at the AIPs around Europe or better still read Euroga to see that avgas availability is becoming more and more scarce. Particularly in certain countries. In many cases the avgas that remains is at larger airports where landing fees/ handling/pump fees are rising quickly. Is the increase in avgas prices due to Covid 19 likely to descend following Russia’s invasion of Ukraine. I can see a point in the not too distant future pilots will need to fly up to an hour from their base, with all the costs that will involve in order to get avgas and then another hour to return to base. Those with smaller Lycoming or Continental engines will instead switch to more available fuels such as mogas.
It will be a steady decline IMO, but not necessarily as slow as many in GA would like it to be.
TEL was removed from auto fuel starting in the 70s, in the US, because it rapidly fouls catalytic converters used to remove by-then US regulated tailpipe emissions. Since those emissions aren’t regulated by EPA for aircraft, and they don’t use catalytic converters, they weren’t affected.
The concern over lead oxides emitted from aircraft came much later, as activists saw a ‘head sticking up’ in relation to cars. The same kind of thing continues to affect lawnmowers, leaf blowers etc and other outliers today even when the total amount of fuel they burn in combination is very small. The health issue is not IMHO driving this, if it really exists, its an ideology based on uniform compliance for every technology and application, regardless of impact.
This doesn’t take away from the benefits that GA would accrue if we didn’t have to deal with lead oxide deposits in oil and engines, especially if we can buy fuel that maintains the high quality components of Avgas relative to auto fuel, which in addition to being low quality fuel in many respects has also become quite nasty stuff to be in contact with from the health POV.
