July 2021
The technique of approval by way of an STC is still problematic for a drop-in or blended product. For example, even if GAMI gives away the STC approval for free, how do they ensure that their fuel product isn’t sold to an airplane that doesn’t have the STC “installed”? I know George says he can print out the STC on the fuel receipt, but installation of an STC on an aircraft isn’t something a pilot can do. Even a garden variety A&P can’t do it. A major alteration needs to be accomplished by an IA with a form 337.
Or perhaps this is one of those cases where we decide that the presence of an STC doesn’t mean something is a major alteration? (Rosen sun visors anybody?) If it’s not a major alteration (if it is a minor alteration) then we’re back to only needing an A&P to sign it off.
If we’re saying it’s not an alteration at all, then do we care what airplanes are covered by the STC in the first place?
It’s a slippery slope.
2 replies
July 2021
▶ system
You know, this GAMI fuel is kind of like the Covid vaccines. Either it works, or it doesn’t.
STCs for this are like masks for the vaccinated. It’s all about control; not “the science.”
1 reply
July 2021
There’s already states that will increase the taxes or outlaw leaded fuel by year’s end. This transition will be sooner and faster then people are reporting. As for STCs, most aircraft that eligible for autofuel have acquired an STC with no problem that I’m aware of. Why should this be any different?
July 2021
This is yet another illustration that the FAA really doesn’t want to bother with General Avation, but they can’t bring themselves to get their foot off the neck of GA. That’s why I refer to them as the “Friendly Airline Agency”. In their perfect world, GA would not exist and they would only have to deal with airlines and manufacturers like Boeing and Airbus. No one at the FAA has any incentive to take a chance on approving something new that could come back to hurt their career path. Also, in our economics driven world, the engine manufacturers have no incentive to change their engine designs to adapt to unleaded fuels. Continental and Lycoming could/should have seen this coming over 30 years ago - plenty of time to develop engines and ignition systems capable of accommodating lower octane fuels. But jumping over the many hurdles of the FAA - both in terms of time and expense - was not worth it when they could continue selling the existing engines that people were willing to buy. I congratulate George and the GAMI team for sticking to their guns and producing tangible results. It will be interesting to see how the flying public accepts it.
July 2021
There is zero evidence that 100LL use is causing health issues. There is zero measurable evidence that piston GA affects the global climate.
What we have here are unelected “regulators” who are squashing things they just don’t like and don’t think we should be doing. It’s a mad world.
1 reply
July 2021
▶ system
Agreed that this fuel either works or it doesn’t so the need for an STC is moot. But this fact is poorly served by a bogus analogy. All analogies no matter how clever break down at some point along the way. This one didn’t have a chance from the git go.
1 reply
July 2021
There is no minimum safe level of environmental lead. Even small amounts can have devastating impacts on children. More and more environmental activists are documenting residual lead near GA airports.
Banning lead from fuel is a no brainer for politicians as there is no down side from their POV. I am frankly surprised that leaded Avgas has survived this long and so now the challenge is going to be an orderly transition to a UL 100 without local supply outages during the change over.
The thing I am afraid of is that GAMI has a monopoly on UL Avgas. The overall market is probably not big enough to encourage serious competition and so I think keeping Avgas prices reasonable is going to be a real issue.
July 2021
More fundamentally it is a distribution problem.
Beyond the basic underlying g cost of fuel, the two big variables in fuel cost at the pump are taxes and transport. Where is the refinery?
Where is the terminal holding inventory?
How far will trucks have to carry it?
Who will pay that price at the pump?
I have also wondered, frankly, if lead serves to reduce detonation at high power settings, would merely adjusting timing and derating engines a bit solve the problem?
Force=mass X acceleration.
A slight loss of force (with other appropriate adjustments) would seem viable, …certification and bureaucracy aside.
The power to weight of my Cessna 337 is plenty. If I lost a bit of power, physics would impose slightly longer takeoff run, a bit less payload, slower climb etc.
I realize not all aircraft have excess power to spare, but consider the alternative.
With all the variables, at the end of the day what counts is delivered thrust, yes? Which can be measured in pounds.
Anyone out there interested in tying a giant fish scale to a tree and the tail of an airplane, to give us some numbers for resultant pounds of thrust as a function of power settings?
2 replies
July 2021
No minimum safe level of lead? Compared to leaded paint and lead pipes, both of which are now rare as the proverbial hen’s teeth, all other general sources of lead ingestion by children are truly infinitesimal. Given lead is a naturally occurring element present in the Earth’s “environment”, at what point do you stop? You can carry any good idea to excess.
1 reply
July 2021
▶ David_Wartofsky
No need for a big fish scale. Just find an airport with a long runway with no obstructions near the end. Then try taking off with less than full throttle. How much less? Try it at 95% power. Then 90% and so on until you find the minimum acceptable to get safely airborne. Oh, and be sure to do this on a hot summer day with high density altitude. You migh be surprised how quickly your plane’s performance degrades.
July 2021
▶ system
Keep two things in mind about STCs:
- they are well known, one-off/field approvals are not
- the FAA forced George to gat an STC in order to sell matched sets of fuel nozzles, to even stress on cylinders.
Never mind he had not altered any parts, just was reselling them in sets selected by flow testing.
Never mind that SOP in aviation for bearings and tiny light bulbs for cockpits were selected. (In those cases only ones within tight tolerance were kept, the rejects were sold to other users.) Bearings were tested for vibration at low rpm, a measure of non-uniformity of balls/rollers. Bulbs were aged first - a good idea for incandescent bulbs, then selected for brightness.
FAA was so constipated despite George’s engineer-lawyer skills that the debate rose to the gutless Administrator, who convinced George to obtain an STC.
1 reply
July 2021
▶ Keith_Sketchley
I once debated for four hours with an individual in Seattle MIDO about permits for flight testing. Smart guy, usually helpful, but he had a hangup.
And that MIDO office was ignoring HQ policy that clarified.
That was in the era when FAA had issued a permit for a prototype airplane to fly from Oregon to OSH but it never arrived. FAA was probably sued.
One outcome was a standard policy of limiting permits to 500 nm radius. So one day I find myself directing an avionics flight test out of the Seattle area, in a good DC8-73. One item in the testing was to be performed in clear air at altitude, for extra safety.
But weather was deteriorating in the region, so we decided to go to Great Falls MT if necessary. Oh! that’s somewhat over 500nm. Fortunately weather improved so we stayed local. (Do that test over the ocean for extra safety, the rest of the testing was at low altitude.)
In making sure the permit covered what we needed, we did not think about the limit, we had no need to go far and didn’t think that weather would deteriorate. But FAA were silly in not differentiating between a proven fast airplane with modest modifications and an experimental category slow airplane.
July 2021
▶ Arthur_Foyt
The problem with the unleaded push is more the politicians, like Hanoi John Kerry, and media regurgitating claims of eco-activists.
There may be more gummint employees who are more collectivist than the average outside of the gummint, but there is clearly a push by politicians and agencies other than FAA.
July 2021
▶ David_Wartofsky
And when one your Skymaster engines resigns, what then?
I assume you have a twin for a reason.
July 2021
▶ system
“:You can carry any good idea to excess.”
Indeed, which is the problem with bureaucrats like FAA, and with eco-activists who have no perspective in their endless push.
The EPA under POTUS Obama was actively trying to silence people skeptical of its climate catastrophism push.
Aviation is under attack by anti-human activists in any case.
July 2021
OK; Lead is bad for people; if you don’t understand of want to believe that; fine; Lead is also bad for your engine!
Lead shortens valve life; that nonsense that it “lubricates” valves is propaganda which is long since disproved.
Engines operated on unleaded fuel have much longer cylinder life; 50 percent more in the cases I know best.
Most GA engines could easily operate on 91 octane unleaded; think premium mogas with no ethanol (Shell)
Many do with great happiness.
The problem is the firebreathing engines that actually need 100 Octane; this is driving the rest of the market.
The crazy thing is, that the engine companies could have developed electronic engine controls for their current engines, making them perfectly capable of operating on unleaded fuel; long ago.
Why didn’t they do that?
Likely the American Legal System which implies that if you change something, it was previously defective; cue the lawyers!
Current car piston engines operate very high compression on ordinary pump gas; this is more difficult but not impossible on AirCooled engines.
Our engines have primitively low compression ratios; it can be done.
In any case; in a few years, as gasoline for cars disappears, it will be come a more expensive boutique product for aircraft;
Better to get yourself a diesel airplane, because jet fuel will be around a lot longer; sustainable jet fuel is coming fast.
1 reply
July 2021
▶ system
“The crazy thing is, that the engine companies could have developed electronic engine controls for their current engines, making them perfectly capable of operating on unleaded fuel; long ago.”
This is not really true. Aerosance/Continental tried it with what became the PowerLink system. Aerosance’s intent was to eliminate the need for 100-octane by manipulating timing to control detonation. They couldn’t make it work. Lycoming tried with the IE2 system. Similar results. The engine still needs 100-octane.
One reason, I was told, is that acoustic knock sensors don’t work well enough on these engines to respond quickly to detected knock. Also certification challenges.
1 reply
July 2021
▶ system
Interesting, thankyou Paul. Certainly air-cooled piston engines are structurally different from liquid-cooled automotive engines.
Not many people hotrodding puff-cooled VW automotive engines I suppose, though they were used in Porsches and 1981 VW air-cooled engines have computer control. (VW switched to liquid cooled engines in 1982 for its Vanagon line, identifiable by a grill at bottom of front and a label something like Wasserboxer, boxer describing horizontally opposed cylinders.)
July 2021
▶ Keith_Sketchley
And vaccines against SARS2 in fact do not always work and have side effects.
Some are significantly less effective than others, supposedly the case with vaccines rushed out by Communist China and Russia.
Side effects vary, such as the blood clots with one brand. (Rare but does occur.)
