AOPA unleaded fuel demo Baron at 200 hours

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The AOPA unleaded fuel demonstration Beechcraft Baron’s year of flying with two different fuels is ending. The 1966 Beech C55 has logged about 200 flight hours using unleaded fuel in the left engine and avgas in the right. Join AOPA Pilot Editor at Large Dave Hirschman on a flight in the Baron to hear what we've learned.
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[flynjay]

Another note that is missed with the switch to unleaded. Manufacturers will be able to use oxygen sensors to trim fuel burn. This will greatly increase engine life.

[kenmarchbanks]

Maybe we need to take a look at Rotax 4 stroke engines. They run 91 octane unleaded gas and normal automotive spark plugs. I have seen the inside of several with 2000 plus hours with no appreciable wear. The only reason we are still running the 1930’s Neanderthal tech engines in our certified airplanes is due to liability and lawyers. It is time to replace this old stuff.

[Riverdale]

I’ve been running with swift UL94 almost exclusively in my Trinidad for about 200 hours now. Absolutely no difference noticed except for the fact that I no longer get fouled plugs. Borescope revealed no valve issues and compressions were all above 78 at my last annual 2 weeks ago. My IO540 has 980hrs total time I’ve probably averaged a 90%UL94 solution over the last 200 hours. I only fill with 100LL twice on long trips away from home. UL94 is my only option on my home field here in the Bay Area.

[realvanman]

As a non-pilot (but long time aviation enthusiast) looking in from the outside, this is forty years later than it should be, but definitely better late than never. AvGas is a wonderfully high quality fuel. Decades ago I used to buy it for my dune buggies. I always loved the smell of it (probably the lead!), and it NEVER goes bad in storage. It runs GREAT in high performance, high compression engines. But, we never should have been spewing lead into our environment in the first place, and it needs to stop as soon as possible. This progress is truly wonderful news. I hope the new fuels are ultimately even better for aircraft owners than AvGas.

[thrustaviationtooling]

Awesome to see the aircraft in flight! We developed the valve stem measuring tool for that project to measure any valve seat wear. Keep it up!

[andik]

I fly my RV-10 extensively with 91 octane ethanol free Mogas. I always operate at lean of peak during cruise. I don't have any build up of deposits whatsoever on the valves, cylinder heads, sparkplugs or piston tops. My exhaust pipes are clean. I hate putting leaded gas into my plane but do it on X-countries.

[michaelcrowder]

We're using E0 (Ethanol Free) 93 Unleaded MoGas in our plane. We are having a staining issue with the paint as well. It helps if you clean it up quickly, but inevitably we got yellow stains. EAA published a tip on using Goof Off Adhesive Remover Gel to get rid of exhaust and fuel stains. Will have to try that.

[rkm]

Well perhaps the yellow residue is a benefit in that it shows bladder leaks - I assume then both sides were actually leaking. If you find a way to clean it off please let us know, or does it stain paint permanently...

[mrbizi]

I REALLY appreciate their work on this issue. I know NO ONE wants leaded fuel and the mess it creates inside the engine fouling. Likewise, we need to know what happens with 100UL.

[vanland]

I would like to see oil analysis deltas between the two engines.

[dermick]

Thanks for the report - looking at those plugs, I'd say that you need to have a look at how you lean, and perhaps the fuel injection config. Looks like cylinder 2 is the only one running the right mixture. Cylinder 1 looks shamefully rich and oily. Can you show pictures of the 100LL side as well? Sure looks very rich to me. I'd be interested in what George has to say about this.

[kiltedpiper]

Look forward to the sharing mentioned in the video. This is a great test platform.

[thefamilythatfliestogether]

This just confirms all the testing that Gami did. Good to see the real-world results match. When will G100UL be widely available?

[josephsener]

Similar to Jeremy, I have a lot of experience flying in airplanes (usually much larger) with the doors open for rapid egress. I have had doors pop twice. Once when I was a passenger in a Bonanza and the pilot was starting to treat it as an emergency and once as PIC coming out of BJC returning home from a mountain flying flight. In both cases I assured everyone aboard we were fine. At BJC my son was SIC and knows my history and if I was fine, he was fine. We landed, secured the door, and departed back to Chicago.

[flyboy]

4:37 Is the unleaded fuel taking the paint off?

[ADZJ]

The black soot is normal when running mogas too. I think you get it with avgas as well but it's masked by the white dust from the lead. I would like to understand the chemistry behind the various fuels, to me the most sensible approach would be to remove lead from the blend that makes up avgas today, and then make the absolute minimal changes to that to get the octane back up to 100.

[heli_yeah]

Any oil samples taken to compare the unleaded oil against the leaded oil? That must soot from the unleaded is concerning and it can wreak havoc on bearings (think diesels). I’m wondering if the unleadeds soot will require more frequent oil changes to protect the engine.

[scottbrooksby]

I ran my Cherokee 235 for about 7 years on 87 Mogas. It ran cleaner and had no problems. This was a Lycoming O-540 B4B5 at 235 HP. Why the need for 100 octane? I see notes that compare 100 octane, but what about regular Mogas or 91 octane Mogas?

[velovettacycling]

Was hoping for more info... valve recession or any abnormal findings on valves? Will that soot on the spark plugs require extra maintenance? Will I start failing magneto tests on runups more often? If it is so staining, can it leave deposits in fuel lines or injectors?

[Triple_J.]

Getting TBO raised from 2, 000hrs to 2, 200hrs will be a significant benefit for commercial operators. It will help offset the price of this fuel, and then some.