AVGAS over by 2024 in Europe
 

It looks like the future of AVgas in europe is doomed.
The supplier of lead Thetraetil additive ( 0,5 grammes per liter of fuel) is based in the UK. UK is out of the EU.
The ban for Avgas in europe is starting to gain grounds in Gemany due to the green party, it will spread quickly; The issue will end up in Brussels at Parliament in the next years, wher few are likely to defend any bill in this respects.
The search for consensus at any cost in Euope is strong among political parties, nodody is likely to support owners of old dynosaurs engines like Lycoming and Continental.
The training industry shifts towards the use of Jet A1 equipping diesel engines. This will be a good justification for potential lack of support.

AVgas no longer produced in Europe but not banned? It will need to be imported from the US, cost at the pump ? easy around 4-5 euros liter.
AVgas banned in the next years ? Game over.

The leaders in research for an alternative aditive to anti knock lead properties, GAMI indutries in the US, are struggling to find an alternative but so far no headyway.

Here we go, up for a nasty surprise..

Not as bad you make out. If there are problems with the future availability of AVGAS 100LL, it will not be the end of piston-engined flying. AVGAS 91UL has been around for a decade or so, and is suitable for most GA engines. If you look at the website of the UK's Light Aircraft Association, you will find a long list of engines that can use that fuel. Yes, it's a UK specific approval.

I understand that the EASA position is that they are OK with it if it's approved by the engine manufacturer. But - don't take that comment as authoritative.

Hopefully, but I am not aware of AVgas 91 UL is it only available in UK ?, I only know use of Mogas unleaded 95 or unleaded 100 on rotax engines.
Some use a blend of mogas and avgas 100LL on old big engines, but with mixed results. Overhauls of these old Lyco's and continentals are tremendously expensive. So use of adequate fuel is advised.

It is also about time, that electronic ignition varying spark advance in relation to piston angular velocity, featuring an anti knock sensor to prevent detonation makes it debut in aviation; Perhaps with 1 magneto as a back up for redundancy. Then alcohols and benzene additives used in mogas would severy increase the vapour lock tendency on hot starts in hot temperatures and consistency of operation at higher altitudes due to thin air lack of pressure.

The gliding club I fly at has been using Avgas 91UL on the Pawnee tugs (big Lycoming) for a few years now with no problem.

Markkal: our airfield supply of UL91 comes from Poland!!

I have been using UL91 unleaded Avgas legally on my Certified Lycoming 180 powered light aircraft for years in the South of England.In my opinion the engine is happier on the unleaded fuel than the occasions when I revert to leaded.Its not going to be an issue for the vast majority of the GA fleet and the warbirds etc can afford to fund specialist stocks of fuel. Regards Stampe
Fly Safe considerate and compliant !

Your assertion about GAMI is wrong. G100UL is gaining traction in the US and is becoming certified for more and more engines. including Turbocharged and big warbird engines.
The problem is will it ever be certified by EASA, and how much will it cost.
If not G100UL, there is 91UL already available in the EU (made by Total among others), or Mogas (E5).

Tx for info, this is good news;
Was following closely GAMI developments but not recently. , I will dig into it, though at the moment have never seen or heard about 91UL or 100UL fuel. Only mogas E5 used on Rotax..At least at airfields in central & southern europe

What about Warbird flying?

markkal

Don't know where piston angular velocity would come from. I do, however, run an experimental Lycoming YIO-360 that has dual electronic ignition with rpm and manifold pressure inputs to spark timing. No knock sensor.

Hi EXDAC,

Here we go, dual electronic ignition will help solve the problem, why I don't have the option to install it in my AEIO 580 lycoming ?

Piston Angular velocity affects timing: ( The time betwen the spark and optimal propagation of combustion inside the cylinder so that it reaches peak pressure after TDC - Top Dead Center-) in an engine with magnetoes is fixed, expressed in degrees at the crankshaft flange around 23 degreees before TDC called timing advance.
This to allow for propagation of flame so that it reaches peak pressure after TDC. But this work within a limited range of RPM's.

The timing is indeed fixed but the piston travels faster or slower (Angular velocity) accoprding to RPM's.
This changes the propagation of the flame in the cylinder in the sense that if peak pressure is reached later (After TDC, high Rpms) there will be loss of performance but no damage.
If it happens before ( Slow rpm's slow moving piston high manifold pressure) then we have a a rising piston in cylinder likely to work against a peaking pressure before TDC.
Peak pressures lead to premature self ignition of mixture .
Here lies the danger:
Detonation, it can damage the engine.

Lead thetraetyl was discovered in the US prior to WW2 . Its purpose was to delay the propagation of the flame inside the cylinders to prevent self ignition and detonation.
This is also the reason the German aircraft engines had trouble reaching the power to cubic displacement ratio US engines were capable of. They did not have the equivalent fuels, They were limited by detonation.

In the automotive industry, with the advent of electronics and stringent emission controls, timing is no longer fixed, it is variable delayed or advanced,, computer controlled and depends on the angular velocity of the piston and internal pressures. There is also a knock sensor capable of sensing the advent of detonation ( It was devised for anti pollution purposes, but regulates timing advance so as to optimise the full combustion of mixture in cylinder, therefore performance).

Detonation means higher pressure inside cylinder, high operating temperatures, and low engine output. Warbird flying ? This can be a problem without the right fuel...

I only questioned the term "piston angular velocity". The motion of a piston is linear and its linear velocity and acceleration are directly related to crankshaft angular velocity. The piston itself has no rotation and no angular velocity.

Variable timing existed on car and motorcycle engines long before stringent emission controls were a factor. Engine speed and manifold vacuum were both used to control timing of mechanical distributors and some motor cycle magnetos had centrifugal timing control.

Yes you are right I expressed myself wrongly, the angular velocity is due to the rotation speed of the crankshaft, determining advance; The piston velocity is linear.
What I wanted to say is that electronic ignition varying "timing" could allow much more latitude in terms of fuels that could be used, as it seems there is no additive which is likely to slow down the propagation of combustion process of burning gasoline to replace tethraetyl lead.

UL91 works perfectly well in the Gypsy Major of my 1938 DH Tiger Moth.

If the crankshaft rotates with a linear angular speed, does the piston then not travel with a sinusoidal speed?

Motorcycle and car magnetos were equipped with simple advance/ retard mechanisms from very early in the history of the internal combustion engine. The early ones were manually set, e.g. via a rotating plate holding the points and adjusted via a lever and cable, but later ones do have automatic advance, working on a centrifugal mechanism. My daily transport used to be a BSA A7SS, with an advance/retard lever on the handlebars so I quickly got used to adjusting the timing and have often thought it strange that aircraft mags, in general, despite being more prone to detonation, weren’t normally so designed (apart from the “impulse” mag starting device to avoid kick-back).

I’m sure someone here will tell us that some aircraft mags do have them….

nostalgia diversion
 

Mine used to be an A10 Golden Flash. The iron head Flash had centrifugal advance but alloy head Rocket had manual timing control.

https://www.nytimes.com/1978/08/06/a...tz-farben.html
Ethyl was made available to the Luftwaffe through many sources , one plant in England shipped it to Portugal and it was shipped indirectly to Germany through many covert channels . Many useful historical facts now becoming more available as more government documents are released .
Although the names of the shareholders in some transactions may never be publicly known . Might been interesting to know if the Luftwaffe ever bombed the shareholders and suppliers by mistake .