FAA Wants All Aircraft Flying On Unleaded Fuel By 2018

coondoggie writes "The Federal Aviation Administration (FAA) this week put out a call to fuel producers to offer options that would safely let general aviation aircraft stop using leaded fuel by 2018. The FAA says there are approximately 167,000 aircraft in the United States and a total of 230,000 worldwide that rely on the current 100 octane, low lead fuel for safe operation. It is the only remaining transportation fuel in the United States that contains the addition of tetraethyl lead, a toxic substance, to create the very high octane levels needed for high-performance aircraft engines. Operations with inadequate octane can result in engine failures, the FAA noted."

Comments

Thanks Slashdot.

[Capt.DrumkenBum]

Now I know where I can get leaded gas for my old car. :)
Off to the airport. :)

Re:Thanks Slashdot.

[LDAPMAN]

I've seen the Missouri State Police show up at a livestock auction and check every pickup as they leave. They were writing tickets by the bushel.

Re:Thanks Slashdot.

[Anonymous Coward]

Mix two different octanes of avgas together and the dyes disappear. It is a feature of avgas to alert pilots in case they mix octanes.

Re:Thanks Slashdot.

[Anonymous Coward]

Bullshit. You clearly have *NO* clue how general aviation works. Anyone can go to the airport with a gas can and use the self serve station. Records are not kept. You do not have to own an aircraft to buy avgas. People at the airport here use it in the lawn mowers, the tugs, golf carts, chainsaws, etc. Hell, I use it in my 2-stroke RC car. I've bought 100LL all over the state on my personal credit card for aircraft I don't own.

Don't present as fact that which you have no clue about.

Re:Thanks Slashdot.

[mikestew]

But when I put it in my motorcycle, whooopeeee! Goes like a rabbit!

Not unless you changed the ignition timing, raised the compression, or did anything else that could benefit from higher octane. Otherwise you spent a bunch of money for a gasoline-flavored placebo.

Re:Thanks Slashdot.

[kick6]

Sorry, I must disagree.

The bike I ride is water cooled and uses CV carbs. A one-in-four gal mix seemed to increase torque somewhat dramatically. Were the carbs clean? Yes. Valves adjusted? Yes. Compression fine? Yes.

Hilly country rides became immensely pleasurable, although yes, the engine temp increased two notches in ten. Unfortunately, that doesn't translate to degrees on the bike's thermometer. Nonetheless, it was wahhhhhoooo time.

Placebo effect entirely. In fact, the bike actually made LESS power on the 100 octane than it did on the lower octane fuel. In all scenarios, the best power is made on the lowest octane fuel that doesn't result in detonation.

caveat: assuming similar fuel composition. Therefore, if the pump gas in your area has 10% ethanol, the non-ethanol avgas will run slightly better. However, the increase in energy density from the lack of ethanol is offset by the inefficiency of combustion associated with the higher octane burning significantly slower...so we're back to the placebo again.

Re:Thanks Slashdot.

[Deadstick]

It also smells different. I don't know why.

Mercaptans, organic compounds that occur naturally in crude oil. They seriously stink; methyl mercaptan is what your gas company puts in the gas so you'll know when you have a leak, and T-butyl mercaptan is essence of skunk. Get car gas on your hands, wash with soap and water, and you'll still smell the mercaptans.

Mercaptans also congeal with age and gum up fuel systems. Aircraft operators take that a little more personally than car owners do, so avgas has the mercaptans refined out.

mostly some small private planes left

[Trepidity]

It's piston-engine stuff like Cessnas that make up the remaining leaded avgas users, and even there, only the subset of engines that require the 100-octane avgas. Both newer and some older stuff can use 91-octane stuff that's now unleaded.

Re: mostly some small private planes left

[Anonymous Coward]

And with about 30 years, you might get the FAA to approve the engine to put into that airplane. We are not talking about your old junk car sitting in the back yard here, you don't get to just put whatever you want into it. Certified aircraft require FAA certified parts, which includes the engine. This has nothing to do with being authentic, it has to do with government regulations and laws.

Re:mostly some small private planes left

[GoogleShill]

Ethanol is a very bad thing to put in avgas, which is why you won't find it at any airport pump. It has this terrible problem of absorbing moisture from the air while it's sitting in the tank, parked, then releasing it as water when you're at altitude. The water sinks to the bottom of the tank and gets sucked right into the engine.

Re:mostly some small private planes left

[ttucker]

As water is absorbed from the atmosphere into the gasoline/ethanol mixture, a point comes where the ethanol/water mixture is no longer miscible with the petroleum part. Since ethanol raises the octane of gas; when it leaves, the octane of the separated gasoline layer is lower (think 83-84). This is horrible for engines, ie. it destroys them. The water/ethanol mixture is also horrible for engines because it dissolves gaskets, and generally does unfriendly things. In fact, it can even act as a substrate for petroleum eating bacteria.

The laws of physics prevent any fuel storage system from being hermetically sealed, sorry. Some are better sealed than others.

If you don't believe me, ask someone that owns a lawnmower, or any other small gasoline engine.

Who's going to pay for it?

[Anonymous Coward]

So in 6 years, the FAA expects 167,000 aircraft owners to swap the engines in their aircraft for an unleaded engine? In 6 years companies are supposed to develop an unleaded engine that will fit in every type of small prop aircraft currently flying? Yeah, not happening.

And as a small single engine plane owner myself, I'll be damned if the government forces me to spend 30K on swapping out a new engine, then more on inspections and re-certification of the aircraft.

Re:Who's going to pay for it?

[Anonymous Coward]

So, you expect everybody else to breathe in your brain damaging exhaust to save you some bucks.

Tell you what, why don't you route your exhaust through the plane cabin and filter it with your lungs first.

Re:Who's going to pay for it?

[fuzzyfuzzyfungus]

As the owner/operator of a complex network of around 100 billion neurons, along with support infrastructure, I'm not entirely sympathetic to your desire to continue emitting lead. Nothing personal.

Re:Who's going to pay for it?

[Kaenneth]

I'll be damned if the government forces me to spend 30K on swapping out a new engine, then more on inspections and re-certification of the aircraft.

I'm not questioning that figure (because I know it's true) but why do airplane engines cost so friggin much?

Compare to the price of mid-air failure.

Re:Who's going to pay for it?

[joe_frisch]

They are also much lower volume production than car engines. The designs are different enough that it isn't easy to just substitute automobile engines for aircraft use. Its been tried, and has worked in some cases, but not many.

Basically aircraft engines turn slowly (usually 2700 rpm max) because the propeller tips need to stay subsonic. Gear boxes are very heavy because of the large moment of inertia of the propellers and haven't worked very well in most installations. The low engine speed means that it needs very large displacement (9 liters is not uncommon) to get the required power. Light weight / high airflow give you air cooled, aluminum-finned engines. The aircraft engines are actually very efficient at their normal operating point. Part of this is due to the high compression allowed by high octane fuel.

Re:Who's going to pay for it?

[joe_frisch]

There have been some improvements in propellers - Hartzell makes some "scimitar" shaped propellers that are a bit quieter and marginally more efficient. Not a lot to be gained though since standard propellers are pretty high efficiency (maybe 90%?).

What you are suggesting is using smaller diameter propellers that turn faster. There unfortunately you are fighting aerodymaics. Propellers are wings. Wing tips add drag, so you want as few as you can. Thin wings are more efficient than fat wings. This pushes you to a small number of small thin blades - and 2-blade, think props are what you see on small aircraft.

There is a limit though in how much power a 2 blade thin prop can deliver so as engine power goes up, you get more blades (3, 4, sometimes ~7 on prop airliners), and the blades get fatter. This all decreases efficiency, but there seems to be no way around it. So, you could go up in prop RPMs but the loss in efficiency so far hasn't been worth it. With a single engine plane its also difficult because if the prop gets smaller in diamter, it is mostly shadowed by the fuselage of the aircraft. Twin (or more) engine planes can have smaller props out on the wings (and some do), but that is a small part of the general aviation market.

Before someone asks: piston engines are more efficient than turbines, but much worse power to weight. Large aircraft use turbines because the power to weight is so high that they can get to very high altitudes where the air is thin and there is low drag at high speeds. Flying that high really requires a pressurized cabin, so you don't see many turbines on small aircraft.

Problem is not the technology but antique planes

[quarterbuck]

The issue is not with airlines (which use Jet fuel) or with Commercial operations (mostly using newer engines). It is with the flight schools and other General Aviation users.

The problem with leaded fuels is not really that technology to use unleaded is not available, but that most of the General Aviation Fleet that is flying is older technology. Majority of the GA fleet are from 1970's or 80's when Cessna and Piper dominated the market.
Then came lawsuits (frivolous and otherwise) and most of the manufacturers filed for bankruptcy. The airplanes from the 90s tend to be mostly homebuilt. Post 2000s a lot of the companies came back from bankruptcy and started making airplanes again. The only problem is that a new Piper costs about $200K while a perfectly usable 1970s Piper with overhauled engine and modern avionics is only about $30K. Airplanes last a lot longer than cars if regularly maintained. So most flying crafts tend to be old.
So these older planes which were designed for leaded gas get recertified for low lead gas, but can never use unleaded.
Newer aircrafts tend to do two things,
1) Run on motor gas (mostly involves certifying for unleaded gasoline) . This has the nice side effect that the gas tends to be about 30% cheaper.
2) Run on Diesel/Jet Fuel / Kerosine - In this case it sidesteps the entire lead problem and also avoids using spark plugs (depending on the design). Fuel availability is a lot better, though not always cheaper.
One easy solution is to make unleaded mandatory for any Light Sport aircraft (which tend to be the newer airplanes built) and to increase a fee imposed while overhauling older engines (which get done every 1000 hours).
That said, this move would permanently ground the WW2 display fleet that is currently flyable and a bunch of old Piper Cubs and Ercoupes. But they are all pre-ww2, so not a big loss I guess.

Call is for new fuels for existing engines

[DragonWriter]

You also forgot to mention (though you likely know) that getting a STC (Supplemental Type Certificate) for an Unleaded Gasoline engine in the hundreds of models that are still using 100LL is going to take many millions of dollars and years of testing and paperwork to push through the certifying authority, which also happens to be the authority trying to force the issue.

Yeah, its a good thing that the FAA isn't talking about new engines at all, but instead calling on fuel producers to come up with replacement fuels that will work in current engines. Which is stated not only in TFA, which I can understand is a huge bother to read before complaining, but in the first sentence of the summary, as well.

Re:Why?

[sd4f]

the lead in petrol had a few benefits, it raised the octane number, allowing the engines to have higher compression ratios, providing better thermal efficiency of the engine. Also in the era when engines where made from detroit wonder metal (cast iron) certain parts were lubricated by the lead, so they could remain as cast iron, such as valve seats, whereas unleaded fuel has required hardened valve seats to be inserted.

Re:Why?

[Cosgrach]

You must be a young bugger.

The main reason for leaded gas in older cars is for the lubrication that it provides. Running unleaded gas in old VW engines would burn the valves in short order. Lead substitutes do work, but it's an added thing to bother with. Sometimes you can get old heads that have been modified to work with unleaded fuel.

Is an older car worth it? Absolutely! Long after your piece of shit new car packs in it's electronics, my old Land Cruiser will still be going strong. If your POS car is in my way, I'll just roll right over it. And just you try to drive your Fucking Tesla through a four foot deep river crossing.

And just stop it with the 'Think of the Children' argument. Fuck the children.

Fucking Pansy!