The FAA will issue a fleet authorization this year that will allow more than two-thirds of the gasoline piston fleet to operate on 91UL avgas. In a news conference held to update progress on the development of an unleaded high-octane replacement for 100UL, Lirio Liu, the head of certification for the FAA, said the agency plans to issue the blanket approval as part of the initiative to get rid of lead in avgas. "We expect approximately about 68 percent of the general aviation fleet will be able to use the UL91."
Doesn’t look like the right facility for Boeing to use for low speed airliner Loads, and Stability and Control. They’ll have to continue travelling to the UK to the QinetiQ facility in Farnborough. Before retiring, I did Loads wind tunnel work for 15 years.
A good tunnel is an asset. The worlds best are privately run.
“What we’re going to do with this facility is literally change the world,” said NASA Langley Research Center Director Clayton Turner. Can we just cut out the hyperbole aimed at the technical ignoramuses who run the federal government? And stop using buzz words like “sustainable” to appear the enviro extremists. I’ve visited numerous wind tunnels in my 40+ year engineering career. The most advanced was the private tunnel in Switzerland built by Sauber for Motorsports.
“the first large wind tunnel to be built by the agency in more than 40 years”
Well, yea, because we arleady have a hundred years worth of data on the subject and CFD is superb at filling in any gaps. You don’t change the world by redoing old tech and redoing old missions. I agree with Kent that better testing is already being done.
I remember long ago when people would be proud that the US has a unique research and development facility that enables our industry to stay ahead of the world in aeronautics and exploration. This facility is geared directly to the areas that CFD is not very good at. And where is this better testing already being done for atmospheric entry parachutes and vertical takeoff systems? Hint: Not at a wind tunnel for automobiles. And if tunnels are useless, why doesn’t the free market use CFD instead of “the most advanced” wind tunnel?
How about that the old tunnels are inadequate for hypersonic research. Why was this omitted from their press release? Oh…I guess we’re too stupid to figure that out on our own.
NASA would do well to select narrators that have better diction; parts of this were barely intelligible.
Also, regarding why this was built when other tunnels would suffice? NASA has pork project grants just like every other agency that has to be used or lost. The good news is that more in lower-turbulence will give better results for drag reduction methods.
And the bleep wants people to buy a headset instead of NASA smartening up and getting better recording equipment and/or choosing narrators on theatre terms (diction, projection, pace)?
Does this mean that the valves and seats will have to be replaced? In old cars, those that were designed for tetraethyl lead long ago, when going to unleaded fuels those components need to be upgraded as I read in “Hot Rod” magazine years ago.
I don’t think it’ll affect the valves. Based on an experience of mine 30+ years ago, where I ran a few tanks of 100LL through my '79 subaru (which had unleaded valves but no cat). I thought I’d be ok, nope. I later spoke with an A&P asking why 100LL still burned the hard valves but doesn’t hurt aero engines. I was told aero’s use titanium valves.
Will these new fuels be stable for “two years in tropical conditions” as does Mil Spec 100LL?
Auto fuel can start to deteriorate in as little as 30 days.
Old cars weren’t ‘designed’ to use lead. And lead never ‘lubricated’ or ‘cushioned’ anything.
The main problem with cars using unleaded is the fuel had lower octane than before. Oh, the sticker on the pump still said “89 Octane”, but now the unleaded fuel had exactly 89 octane (or even 88.9), whereas before with leaded gas it was often a couple of points higher. That’s because it was cheap and easy to add a bit more lead to guarantee the octane rating. But with unleaded it was much more difficult and expensive just to reach the rating. So cars that ran fine on the old “89” and pinged on unleaded “89” were really cars that needed 91+ octane all along.
The problem wasn’t the lack of lead. It was the lack of octane.
Add if those cars had unhardened valve seats, where seats were cut directly into cast iron cylinder heads, the continuous pinging would result in valve-seat recession. But airplane engines use hardened valve seats. They have to because aluminum is too soft to machine a seat directly.
Getting the lead out will make airplane engines run better, not worse.
Even for old cars, the statement that unleaded gas burned the valve seats was a myth.
There is actually only one car model (Pontiacs) that that happened to amd that was due to a design flaw in the vakve seats pertaining to that particular model.
Why are we still talking about unleaded AvGas like it’s not here yet? G100UL is already certified in 100% of the fleet, which sounds much better than “68 percent of the fleet.” The lead-free future is here, and it’s G100UL; we just need to get it pumping!