General Aviation Modifications Inc. says long-term exposure of painted aircraft surfaces to avgas with high aromatic content, like its G100UL and, potentially, 100LL is "not recommended" but "incidental contact should not cause paint to peel." The company was responding to a video released by a California A and P who conducted his own set of material compatibility tests on the high octane unleaded fuel. Michael Luvara found that when G100UL was allowed to evaporate on a painted surface, the residual liquid left after the most volatile constituents would, over time, cause paint damage. He also found that nitrile O rings swelled when submerged in the fuel for five days.
Well, Avgas 100LL being typically about 10% Aromatics and all UL Avgas 100âs being in the region of 30% aromatics (and more)⌠BIG DIFFERENCES to the airframe components are expected, and the consequences could (and possibly will) be catastrophic at some point for a bunch of airborne humans.
Letâs look back to the introduction of 100LL several decades ago when its 10% replaced the <1% aromatics in the BEST avgas (GREEN Avgas 100/130) which these engines and aircraft components were actually designed for, and we see that the floats of Gipsy carburettors used at the time were swelling (due to the aromatics) and jamming in the float chambers with the corresponding engine failures in flight. Why do we have to continue this nonsense of trying to solve a clearly non-existent lead pollution issue. Due to the lack of any harmful levels of lead being found even around the busiest GA locations that can ACTUALLY be attributed to aviation operations (to legal standards of scrutiny) and which are not just the legacy of millions of cars because lead doesnât just disappear - like magic - we are just wasting our time and money. We risk sending aviation safety back decades, and repair and modification costs literally through the roof chasing a solution that isnât needed.
Letâs see the outcome of the first court action that results from an âunsafe conditionâ being legislated upon the industry, and then we will know that we truly effâd-up this time.
p.s. The ASTM control on âSpecific Energyâ (43.5 Mj/kg min) is an indirect control on the upper aromatics limit on 100LL and 100/130. Thanks ASTM but it should have limited it further than it does.
âWhy do we have to continue this nonsense of trying to solve a clearly non-existent lead pollution issue.â
Because we are human beings and because of that we believe we are for the most part brilliant. Human beings are so stupid we actually not only believe in âglobal warming,â we have actually elevated it to being a religion. It is no wonder we think lead in aviation fuel is an issue. Humans are all collectively very dumb and stupid while at the same time believing we are so smart.
The interesting thing about all this, is the continuing denial of reality by some.
Gipsy engine carburetors are quoted as having a problem with certain fuels. The Gipsy engines I fly are clearly placarded by the manufacturer as allowing zero lead in the fuel. Some later Gipsy engines could tolerate lead, but it is actually bad for all engines; and people.
Gas is bad for paint; old news.
GAMI tested their fuel with O rings; the results were written up; old news.
Lead for fuel is made by one company in the world; shipped in a very old ship that could fail inspection any time.
The ship fails, or the company turns off the tap; no more lead; abruptly.
Lead is going away folks; your engine will be better off; get over it!
The current resistance is part willful ignorance, part propaganda from companies making a big profit on 100LL; companies who donât want to give up their gravy train.
The other problem is the Lawyer culture in the US;
Any change in anything brings the lawyers out; they travel in voracious packs.
Reality doesnât matter to these lawyers; they make their money by suing; they win financially either way.
100LL is a boutique fuel and itâs hardly a gravy train for any of the producers. Itâs a niche product for them, and I bet their stockholders wouldnât shed a tear if any of them stopped selling 100LL tomorrow. Retailers on the other hand, make a decent profit on it, which is why prices range from $4.30/gal to over $8.00/gal just here in the US.
Your diatribe against lawyers shows you donât understand how the system works or you got taken to the cleaners in a divorce. Either way, itâs not the lawyersâ fault. They are just instrumentalities of their clients.
The part of your aviation experience I like best is when you turn into a bat and fly around the room. A hint: if you truly beleive the sky is falling, downât stand around outside looking up with your mouth open.
What I was saying has NOTHING whatsoever to do with lead, but is the key problem at the core of every single unleaded avgas available to date, but some are still in complete and utter denial, unfortunately.
Perhaps, but with refiners squeezed by local eco-activists they may well avoid the distraction and production resources albeit small required. (A change disrupts operation.)
Refineries have been closing in the US.
If specialty fuel can be mixed offsite that avoids disrupting refinery operations.
but it should have limited it further than it does.