EPA needs your input

[Tom-D]

http://a257.g.akamaitech.net/7/257/2422/01jan20071800/edocket.access.gpo.gov/2007/E7-22456.htm


There are many aircraft engines that will not operate on 93 oct UL. It is my belief that if your engine does not have an auto fuel STC availible it must be de-rated to run 93UL.

This is a big deal folks, WE should get on this big time.

 

[poadeleted20]

There are many aircraft engines that will not operate on 93 oct UL. It is my belief that if your engine does not have an auto fuel STC availible it must be de-rated to run 93UL.

The 91/96 UL aviation fuel available in Europe is already approved for use in all Lycoming engines originally certified to use the old leaded 91/96 avgas, as well as all 80/87 octane engines. See Lycoming Service Instruction 1070N. Only engines originally certified to use no less than 100/130 or 100LL are not approved to use the new 91/96 UL aviation fuel. Further, given Sunoco's success in producing an unleaded 100 octane racing fuel for NASCAR, I should think that a 100 UL avgas is achievable with current technology. I for one will be happy not to have to pick the lead globs out of my spark plugs every 50 hours.

 

[Tom-D]

The 91/96 UL aviation fuel available in Europe is already approved for use in all Lycoming engines originally certified to use the old leaded 91/96 avgas, as well as all 80/87 octane engines. See Lycoming Service Instruction 1070N. Only engines originally certified to use no less than 100/130 or 100LL are not approved to use the new 91/96 UL aviation fuel. Further, given Sunoco's success in producing an unleaded 100 octane racing fuel for NASCAR, I should think that a 100 UL avgas is achievable with current technology. I for one will be happy not to have to pick the lead globs out of my spark plugs every 50 hours.

Your service letter states that UL will not harm the engine,
it states
quote

The importance of using the fuel specified for a specific model Lycoming engine has always been stressed
in Lycoming service publications. However, if the specified fuel is not available, a higher grade fuel may be
used, subject in some instances to the restrictions described in the footnotes to the following Table of
Specified Fuels. The chart showing specified and alternate fuels that can be safely used in no instance
permits use of fuels of lower grade than that which is specified. Also, it is not permissible in any instance to
use automotive fuel in aircraft engines, regardless of octane or advertised features because of the corrosive
effect of its chlorine content and because of vapor lock that could result due to its high vapor pressure. Any
fuel used in Lycoming engines must conform with Specifications ASTM-D910 or MIL-G-5572F.

But will you also be as happy to loose the preformance? the SB doesn't say it won't cause lower horse power.

Remember the TSIO 360- Cont was already de-rated to use 100LL

Simple BTU theory tells us that UL does not have as many BTUs per pound Pure Gas stock. So you will be required to burn more of it to do the same job, which simple logic tells us, the legs on your aircraft will be shorter.

And secondly, We don't have 91/96 UL here now, nor will we in the short term.

 

[Tom-D]

The importance of using the fuel specified for a specific model Lycoming engine has always been stressed
in Lycoming service publications. However, if the specified fuel is not available, a higher grade fuel may be
used, subject in some instances to the restrictions described in the footnotes to the following Table of
Specified Fuels. The chart showing specified and alternate fuels that can be safely used in no instance
permits use of fuels of lower grade than that which is specified. Also, it is not permissible in any instance to
use automotive fuel in aircraft engines, regardless of octane or advertised features because of the corrosive
effect of its chlorine content and because of vapor lock that could result due to its high vapor pressure. Any
fuel used in Lycoming engines must conform with Specifications ASTM-D910 or MIL-G-5572F.

Want to talkabout that ?

 

[poadeleted20]

But will you also be as happy to loose the preformance? the SB doesn't say it won't cause lower horse power.

Since my engine was rated with 91/96 octane fuel, using the 91/96 UL fuel in my O-360-A4K won't cost me power, and may save me money in the long run by reducing maintenance costs dealing with lead deposits (or saving the costs of buying, storing, and adding TCP for those who do that).

Remember the TSIO 360- Cont was already de-rated to use 100LL

Can't speak to that, but I do support the effort to develop a 100UL avgas for those engines which can't run on less, and which obviously could also be used in the 91/96-rated engines. It's a simple political fact of life that using leaded fuel makes us a target for those looking for an issue on which to campaign which provides the opportunity to look good to the mass majority while causing problems for only two tenths of one percent of the population (that's 600,000 pilots out of 300,000,000 Americans).

Simple BTU theory tells us that UL does not have as many BTUs per pound Pure Gas stock.

I'd like to see the proof of that statement.

And secondly, We don't have 91/96 UL here now, nor will we in the short term.

For all the reasons stated, I'd like to see that change.

 

[poadeleted20]

Any fuel used in Lycoming engines must conform with Specifications ASTM-D910 or MIL-G-5572F.

Want to talkabout that ?

I think that's what I suggested -- using the existing (but not yet available in the USA) 91/96 UL avgas or, even better, getting a 100 UL avgas, both of which meet (or would meet) ASTM-D910.

 

[Tom-D]

I hope you did not draw the conclusion that I like lead in our fuels, the simple fact is the TEL is the best burn rate retardant we have. Any subsitute that is used must be added in bigger quanties than TEL. thus deluting the pure gas stock and producing less BTUs per pound.

This has been proven many many times in the auto industry, running UL in the 60/70 version engines without all the technology we have in todays engines, produces very poor mileage. even worse than they did running leaded fuels.

There isn't a single fuel cell manufacturer that will warentee any cell that has been subject to UL fuels due to the additives in the fuel.

You make the statement that your repair bill will go down.

I overhaul both engines that run UL (auto), and av fuels and from my experiance the auto engines have more dificulty getting TBO than does the av-fuel engines, because the leaded fuels when burned form a grey carbon deposit which is soft in comparison to the auto (UL) fuels which form a hard black diamond like deposit.

This hard depoit will collect on the valve stem and wear the valve guide which is much more expensive to replace than doing the rope trick and getting the soft lead deposit off the valve stem.

but the worse thing UL will do is collect behind the rings and not allow the ring to relax during its cycle of running up and down the choke of the cylinder. this usually results in one of two thing happening.

the first and worse, it will brake the ring, or it will wear the ring and in some cases the land between the rings will fail.

So you see UL is not the end all of aviation engine maintinence, it is just a different set of problems. and usually more costly in the end.

Your Lycoming service instruction 1070N mentions chlorine and its effects, I won't discuss this because I don't know if the 91/96UL contains it or not.

But this is a real corrosion problem in engines using Auto, and Lycoming is not noted for it ability to protect its self from corrosion.

Next, in your quote you failed to note
"The importance of using the fuel specified for a specific model Lycoming engine has always been stressed
in Lycoming service publications. However, if the specified fuel is not available, a higher grade fuel may be
used, subject in some instances to the restrictions described in the footnotes to the following Table of
Specified Fuels.

Lycoming NEVER allows the use of a lower oct fuel, let us hope what we get from the EPA is a usable fuel. other wise the lycoming users will be strangled by that service letter or they will ignore it and every body becomes a test pilot.

OBTW my old warner was certified on 73 oct, but from the experiance I have with UL I won't run it.

BUt that is a moot point, because 91/96Ul is not availible in the US. no one here has experiance with it.

 

[pilotmattk]

The posts thus far don't even mention the high octane needs of current turbocharged engines. I'm no expert on the subject, but from what I understand not even 100UL would work there? The current uncertanty factor as far as sustainable aviation fuels is definately giving me a "wait and see" attitude when it comes to making a first airplane purchase. I'm still a year or 2 out before really seriously doing it (I want IFR + 200hrs for ins reasons) but the current situation has me thinking (twice).

 

[pilotmattk]

The August 2007 edition of Plane and Pilot had an interesting article beginning on page 68 that went on at length about the history and future of lead in avgas. I believe I detect a fairly high amount of political SPIN in the article, but it is interesting nonetheless. The author makes the point that Ethyl alcohol and other additives were available, but could not be patented like TET/lead. Not being a powerplant expert myself, I'm very suspicious of that conspiracy theory.

Here's a link to the issue, unfortunately the article isn't one of the freebies of the month. http://www.planeandpilotmag.com/content/2007/aug/index.html

 

[Tom-D]

there is also a link at

http://www.aopa.org/advocacy/articles/2007/071114epa.html

and

http://www.avweb.com/avwebflash/news/GroupAsksEPAToGetTheLeadOutOfAvgas_196596-1.html

Many of the writers think removing the TEL from the aviation fuel will be a death blow to many of the engines we fly.

 

[poadeleted20]

I overhaul both engines that run UL (auto), and av fuels and from my experiance

When you've overhauled an engine run on ASTM-D910-spec UL avgas, let me know what you find.

"The importance of using the fuel specified for a specific model Lycoming engine has always been stressed
in Lycoming service publications. However, if the specified fuel is not available, a higher grade fuel may be
used, subject in some instances to the restrictions described in the footnotes to the following Table of
Specified Fuels.

Lycoming NEVER allows the use of a lower oct fuel,

I say for a third time -- I am talking only about using a Lycoming-approved grade of fuel, i.e., 91/96 UL in engines certified for 91/96 and/or 80/87. I never suggested using, nor would I use, an unapproved fuel.

BUt that is a moot point, because 91/96Ul is not availible in the US. no one here has experiance with it.

Right, and with some pressure on the government and industry, maybe that will change.

 

[poadeleted20]

The posts thus far don't even mention the high octane needs of current turbocharged engines. I'm no expert on the subject, but from what I understand not even 100UL would work there?

There are some military engines in old warbirds that were designed to run on the old purple 115/145 avgas, and they don't put out full power on 100LL. But I know of no production-certified piston-powered GA aircraft that is not approved to run on 100LL, including the highest performance engines like those in the Piper Malibu and Navajo Chieftan, Beech Duke, and Cessna 421. In fact, Lycoming cautions against the use of 115/145 in engines not requiring it:

Continuous use of high lead fuels can result in increased lead deposits both in combustion chambers and spark plugs causing engine roughness and scored cylinder walls. It is recommended that the use of this fuel be limited wherever possible; however, when high lead fuel is used, periodic inspections of combustion chambers, valves and valve ports should be conducted more frequently and spark plugs rotated or cleaned whenever lead fouling is experienced. See latest revision of Service Letter No. L192.

 

[poadeleted20]

Many of the writers think removing the TEL from the aviation fuel will be a death blow to many of the engines we fly.

Thinking is one thing; results from testing is quite quite another. Further, I see nothing in either article which says anything about a "death blow." The closest I can find is Andy Cebula's comment that there is not currently an unleaded avgas which will run all GA piston engines, and that is true. However, as I said above, given NASCAR's success in obtaining a 100 UL racing fuel from Sunoco, I firmly believe that we have the technology and lack only the motivation to make a D910-compliant 100UL avgas happen.

 

[Tom-D]

I firmly believe that we have the technology and lack only the motivation to make a D910-compliant 100UL avgas happen.

If Friends of the World get lead removed from Av-fuel, what will you burn until we see that happen?

My only concern is the lead time required to get the production going to fill the supply pipeline between you and the refinery.

With the certification requirement and testing to gain FAA approval, who knows how long that may take. And if we rush it how knows what we'll get.

 

[mikea]

Is this 100UL gonna be made alongside auto gas? IOW, my concern is if we get FEWER suppliers of AvGas so we start seeing $8.00 a gallon due to the monopoly.

If it turns out that it's easier to tool up make UL than 100LL, and there are more suppliers and cost is reasonable because of that, I'm all for it.

 

[Tom-D]

Is this 100UL gonna be made alongside auto gas? IOW, my concern is if we get FEWER suppliers of AvGas so we start seeing $8.00 a gallon due to the monopoly.

If it turns out that it's easier to tool up make UL than 100LL, and there are more suppliers and cost is reasonable because of that, I'm all for it.

That is a real problem.

 

[Tom-D]

There are some military engines in old warbirds that were designed to run on the old purple 115/145 avgas, and they don't put out full power on 100LL.:

It's not they won't but are not allowed to because they will detronate.

But I know of no production-certified piston-powered GA aircraft that is not approved to run on 100LL, including the highest performance engines like those in the Piper Malibu and Navajo Chieftan, Beech Duke, and Cessna 421. In fact, Lycoming cautions against the use of 115/145 in engines not requiring it:

Like Lycoming there are several engines that warn against using higher lead content fuels.

For Everyones information

When the large radial engines run a lower oct rating fuel they are held to a lower power setting known as the derated power.

For example, When I ran the 3350 on 115/145 I was allowed to set 65Hq and 2400RPM. (or higher) for take off power

When I ran it on 100/130 I was restricted to 50Hq at or above 2600 (or higher )RPM

on 100LL I was restricted to 40Hq and 2800 RPM. (NO LOWER)

IOW the lower the oct rating the lower the manifold pressure and the higher the RPM setting to stop detonation.

The TSIO-360 cont. engine was first rated on 100/130 at 220 horse power at 2800 RPM. when the FAA forced Contintental to rate it on 100LL they derated the engine to 201 horse power at 41Hq / 2800 RPM.

And If you wish to make TBO you will run it under 37Hq or suffer the short life as the result.

This is the syndrom we face If the lead is emoved from av-fuels. simply because there is no good subsitute for TEL, using the small amount required to get the required results.

 

[Tom-D]

Thinking is one thing;

That is quite right, but we better think long and hard on what we settle for.

results from testing is quite quite another.

Show me the test results and I 'll tell you what I think.

Further, I see nothing in either article which says anything about a "death blow." The closest I can find is Andy Cebula's comment that there is not currently an unleaded avgas which will run all GA piston engines,

If removig one fuel before we have a replacement isn't a death blow what is?

You, yourself have stated that you will not use an unauthorized fuel. Many folks don't think like that and will run auto, in anything they fly.

and that is true. However, as I said above, given NASCAR's success in obtaining a 100 UL racing fuel from Sunoco, I firmly believe that we have the technology and lack only the motivation to make a D910-compliant 100UL avgas happen.

The NASCAR 100UL that you see as the replacement fuel has many ingredients that are not allowed in av-fuel, such as the chlorine the Lycoming service instruction 1070N states is corrosive, and can't be used in Lycoming engines.

IMHO the only hope is that the EPA will set emmisions standards to a level that 100LL can meet. But if they do that, it removes the requirement of removing lead, and removes the insentive to develop a new fuel, test it, and gain certification for it.

We're damned if we do, and damned if we don't.