Unraveling the mysteries of fuel

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985.

Fuel is an item that is very important for the proper operation of our aircraft. Even though the world is full of “fuel experts,” it is still a bit of a mystery.

[Read more...]

Why the controversy about unleaded avgas?

Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985.

The most common question I get concerning unleaded avgas is, “why all of the controversy?”

[Read more...]

Panic about unleaded avgas runs rampant

A few weeks ago I visited AirVenture in Oshkosh. It was no surprise the hot topic of discussion was unleaded avgas. You will be happy to know that panic and ignorance was running rampant.

[Read more...]

How to prepare for the end of 100LL

How should aircraft owners prepare for the switchover from 100LL to its replacement? In a previous post, I stated that if — or when — 100LL goes away, the only fuel that will be universally available for general aviation will be one that is chemically very similar to 100LL, but without the lead, and an octane rating of around 94.

If you have a low compression ratio engine qualified on 80/87 or mid-90 octane fuels, you really do not need to change anything. The only concern is that when the engine is overhauled and broken in on straight unleaded fuel, there maybe a problem with exhaust valve recession. If I owned one of these aircraft, I would wait until 100LL is about to go away and then buy a barrel. [Read more...]

GA’s Catch 22

Why don’t FBOs sell auto fuel? When will unleaded avgas be available — and who will sell it? These questions, and more, abound about aviation’s Catch 22: FBOs will not stock unleaded fuels until the market supports it — and the market will not develop until the fuels are readily available.

A fuel system at an FBO is an expensive thing to install and maintain. Today, it is necessary for FBOs to offer 100LL, as that is the major demand. If an FBO decides to sell a second grade of avgas, then it would need to install a second (or third, if it handles Jet A) fuel tank, filter, pump and related equipment. With all of the requirements for containment, etc., this is a very costly option — and an option that probably will not pay for itself at this time.

If 100LL goes away, leaving only one grade of unleaded avgas, the FBOs will have no use for a second system. There also is the problem of having multiple systems, which increases the chances of misfueling.

As we look into the future, my best guess is that, if we go unleaded, there will only be one grade of unleaded fuel. It would be nice to have multiple grades, but the general aviation market is just too small to economically support more than one grade of avgas.

So what will happen with the new fuels? Basically nothing.  I do not see a significant shift away from 100LL until the government finally says “no more” [Read more...]

Asking for trouble

In college, one of my favorite courses was internal combustion engines taught by Prof. Groves. One semester, the main topic of the course was the differences between spark ignition (SI) and compression ignition (CI) engines. After taking the final test, on which we were to compare the advantages of the SI and CI engines, I stopped to talk to Groves, along with several other students. While we were talking in the hall, another student came up and asked, “What does SI and CI stand for?” I remember Groves just hitting his head against the wall and shaking his head.

I feel this way sometimes when someone asks me, “I was working on my plane recently and did not have any aviation grease, so I used some automotive wheel bearing grease. Is that OK?” Unfortunately, people jump to the conclusion that if it does the same job in an automobile as in an airplane, they should be the same. This logic may or may not work — and if it doesn’t, you can have serious problems.

[Read more...]

The death of Common Sense

Today we mourn the passing of a beloved old friend, Common Sense in general aviation.

It will be remembered as having cultivated such valuable lessons as knowing when to not fly into a storm, life isn’t always fair, and maybe it was pilot error. Common Sense lived by simple, sound principals, including “follow the manufacturer’s recommended maintenance practices” and “the pilot is in charge.”

Its health began to deteriorate rapidly when well intentioned but overbearing regulations were set in place. Those who filed lawsuits because engines quit when they ran out of fuel and airplanes actually require maintenance only worsened its condition.

Common Sense lost ground when people moved next to busy airports and then sued because airplanes kept flying near their properties.

[Read more...]

Debates must continue to find solutions to aviation’s upcoming technical challenges

I recently received a letter, “Is global warming debate over?”, from Peter Mortensen criticizing one of my previous columns. I appreciated his letter and he made several valid points. Letters, even critical ones, ensure that we stay centered and help us ensure that what we write is valid and can stand up to scrutiny.

However, I disagree with some of his comments, including when he says “the debate is over,” implying that we should all accept global warming as fact and not question any part of it. I stated very clearly that I did not have a clue as to whether or not there is global warming. But Mr. Mortensen was apparently offended that I would even question some of the data and how it has been analyzed.

I agree that we should protect our environment, but feel that solutions like ethanol do not help the environment. I’ve read several recent studies that show ethanol actually increases total emissions if one takes into account all production, transportation and manufacturing effects. I feel that our only hope to find reasonable solutions to today’s problems is if we have open and informed debate. Unfortunately, most of the debate today is based on profit or political motive, with the facts slanted to show only the sponsor’s view.

In his letter, Mr. Mortensen also noted that we should do everything we can to reduce global warming — just in case it is real. Besides, what could it hurt? This type of logic just blows me away.

[Read more...]

What happened to auto gas at the airport?

When auto gas was first approved via STC for certain aircraft, there was a lot of support and many airports started to sell auto gas. This was a good deal for many Rotax-powered aircraft, as well as STC’d certified aircraft. But now it is almost impossible to find auto gas on most airports. What happened?

[Read more...]

The demise of 100LL is no surprise

At the recent AOPA Aviation Summit, several industry leaders made the startling comment that lead in avgas is going away. Well, duh, what do you think I have been saying for the last 20 years?

The comments fall into three general areas: The first is the gloom and doom group that feel that it is all over and that we should just scrap all of the planes and have everyone in GA go find a new hobby to dump money into. The second group is in denial — they do not believe the EPA will actually go through with its threat to outlaw leaded fuels. And the third group believes that someone will come up with a miracle fuel that will replace 100LL, cost less, and perform better in all applications.

[Read more...]