Howard Fenton


For 35 years, Howard Fenton’s been telling airplane owners about the health of their engines by analyzing their oil. Howard has spotted everything from broken piston rings to excessive bearing wear to worn valve guides. Once he tracked down an airplane he was convinced was about to throw a jug — and it was. In this month’s Profile, AVweb’s Joe Godfrey talks with Howard about additives, what your oil’s trying to tell you, and how your oil can help you get to TBO.

Howard Fenton

Howard Fenton was born December 9, 1931, in Tulsa, Okla. His interest in engines began early, when he added a Whizzer to his bicycle. He got interested in motorcycles, then enlisted in the Air Force when the Korean conflict broke out. The Air Force trained him at the Aircraft and Engine Mechanics School, then sent him around the country to work on F-89s. After his service career he returned to Tulsa and spent four years at the University of Tulsa. He quit school to take a job with the Sinclair Oil Company, and when Sinclair merged with Arco Howard moved to the Dana Corporation. He spent 20 years there as a sales representative specializing in oil filtration systems. He began doing oil analysis on the inland marine fleet in the St. Louis area — riverboats.

He learned to fly in 1969 in a Yankee. In the early ’70s Arco dropped their oil analysis program, and Howard picked it up. His interest in airplanes led him to create a database of aircraft engines, and Engine Oil Analysis was born. Howard began by learning engine design and oil circulation patterns for radials, small bores, big bores, and turbos. Then he established standards for metal wear in each of those engine designs. Then he gathered data on individual engines, because while all IO-520s have some wear patterns in common, it’s the break in a particular engine’s profile that often signals trouble. Howard’s database began on paper, moved to a Radio Shack 1000, and when he sold the company in April 2002 he had amassed wear patterns for over 6,000 reciprocating engines, plus some turboprops and jets. Good data is important, but interpretation of the data is essential — and Howard personally wrote every analysis opinion for 35 years. Now he’s running an oil filter analysis company called SECOND OilPINION, and still helping owners diagnose problems and bust TBOs.

How did you get interested in flying?

I was the only one in my family interested in it. My father was in the newspaper business, my grandfather was a captain on the Mississippi River, and none of my five brothers and sisters were interested in it. I had an interest in motorcycles which had begun with a little device called a Whizzer, which was an engine you added to your bicycle. When Korea came about I enlisted in the Air Force and went through Air Force Aircraft and Engine Mechanics School at Wichita Falls, Texas. I was assigned to be a mechanic on the F-89 project and spent time in Florida, Georgia, and Edwards, California.

After the service, I came back to Tulsa, and spent four years at the University of Tulsa. I quit just short of graduating and went to work for the old Sinclair Oil Company. I worked as a sales rep until they merged with Arco, then I went with what is now Dana Corporation. I was a sales rep specializing in filtration for 20 years. It was during that period I learned to fly on my own, and have been flying ever since.

Which airplane did you learn in?

I learned in an American Yankee in 1969 in St. Charles, Missouri. I had been transferred to the St. Louis area by Sinclair and a neighbor of mine in St. Charles was an Ozark pilot, as well as a flight instructor, and he asked me if I’d like to go ahead and get the rating. It was the first opportunity when I had the time and the money, so I did it. I’ve got a private certificate with an instrument rating. I lost my medical three years ago — at age 69 — and now I’m passenger in command.

When did your interest in oil analysis begin?

In 1971 I was selling lubricants to the inland river marine fleet — riverboats. When Arco announced they were taking over, the first thing they did was drop the oil analysis program. I saw an opportunity, so what they gave up I picked up.

Had you done oil analysis in the Air Force?

No, when I was in the military they didn’t do it. These days, of course, they do it after every flight. At Sinclair I was reading the laboratory reports for the marine engines, and I decided that this wasn’t too difficult if I could build the database I needed for each airplane engine. I just started out very slowly, picking up one here and one there, and just over the years my database developed. The database began as a rack of notebooks full of paper with handwritten reports. The report would be written and then photocopied, and the customer would get the photocopy. In the mid-’80s I put it all on a little Radio Shack 1000 computer.

Once we got it on the computer it simplified the whole thing. We always ran two computers because we could never afford to be down, so we always had our database running on one, and the reports running on another. We updated our database about once every ten days, and it just grew and grew. My wife and I ran the business for about the first 25 years while I worked for Dana, and then the last ten years of the company I ran it completely. I retired and sold the company to Blackstone Labs in April 2002.

Walk us through what happens to the little bottle of oil after you get it.

The sample goes to the lab, the oil is burned, the vapor is run on a spectrometer, and levels of the various metals that we’re looking for are measured and recorded. Currently we use an argon plasma spectrometer — prior to that we used carbon arc spectrometry. We massage the readings a little bit to correct for drift because on any given day a machine will drift slightly. Those numbers were then put over on the customer’s report, and the customer’s report was then read and an opinion written.

For the entire 35 years that I was in business, I personally wrote every opinion that went out of here. I would look at what our standards were for any particular engine the first few times I saw it. After that I was always looking for a break in the profile for that engine. Elements have been running a constant wear rate per hour, and all of a sudden there’s a break in the profile, and that’s what I’m looking for. I have to be able to recognize it first, and I have to be able to recognize something that may be getting ready to break. Maybe it’s not quite there yet, but I’m unsure of some number that I see. That’s when I call the customer and say, ‘Hey, I’ve got something. I’m not exactly sure what it is but I just want you to be aware of it and monitor it, and we’ll take a look at it on the next oil sample.’ But to do this, I need to know how that engine is built, what’s the internal configuration, what are the components made of, what’s the cylinder bore, what valve guides are in it, all of these little variables.

What’s an example of a profile break that’s pretty easy to interpret?

A broken ring is easy. Generally, a broken ring will score the cylinder wall, so if you have a nitrided iron cylinder wall, you’re going to get iron. If you have a chrome cylinder wall in any one of the various chroming processes, you’re going to get chrome, and if you have CermiNil, you’re going to get a higher level of nickel. You’re also going to get aluminum because usually it’ll go to work on the piston as well, and quite often if you’ve got a plated cylinder wall you’ll get some iron off the ring itself. That’s an easy one.

Here’s another easy one. Some of the Continental engines have a problem with rocker shaft bushings which generates copper. We spot copper in the oil sample and the mechanic tells us, ‘Well, I’ve got some copper flakes in the filter,’ and then you pull the rocker box cover and you’ve got copper laying in the rocker box cover, and most likely it’s going to be a rocker arm bushing.

And what’s an example of a profile break that’s tougher to interpret?

Bearing wear will sometimes throw us. It’s very, very slow. Sometimes when an engine is opened up the mechanic will say, ‘We’ve got some badly worn bearings in here,’ and yet the oil analysis didn’t show a thing because it’s so gradual that we never saw a break in the profile.

Another thing that throws us is spikes. We’ll get a spike in a sample for no reason whatsoever, and on the next sample it comes back down.

Could that be the way the customer took the sample — like the first drop out of the pan?

It could be the way it was taken — there are so many variables. One guy’ll catch the sample during the drain. Another one will say, ‘Well, I’m going to get an interim sample,’ and he’ll go in through the oil filler tube. The next guy says, ‘I forgot to catch the sample, but I think I’ll just take it out of the bucket.’

We had a good one several years ago. I got a sample that was just horrible from one of the engine shops in California, and I called the customer and said, ‘We’ve got to find this airplane, and if it’s already gone out of your shop we need to find it and find out what we’ve got here.’ The shop told me the airplane had already gone home to another city. They looked at it there and in their investigation they had a mechanic admit that he forgot to take the oil sample — even though it was on the work order — so he’d gone over and gotten an oil sample out of the waste oil drum. He was going to cover his butt and I was ready to tell an owner, ‘You’ve got to open that engine up.’

How often did you call and recommend grounding the airplane?

Mostly we made precautionary calls. Once I chased down an airplane that was based in St. Louis and it was on the ramp in Denver when I found it. It was a Mooney with an IO-360, and I got the FBO to flag it not to go anywhere. They pulled the engine out in Denver, and the shop that disassembled it got back to me with some feedback that it would never have made another takeoff. I don’t remember if it was the cam or the crank or a valve, but it was just trashed.

Once I made a call to a guy who had a twin Comanche — this was one of those where I just didn’t like something in the right engine so I called him and said ‘I think you’ve either got a ring or a valve problem.’ It wasn’t enough to say ‘ground it,’ but I was concerned. His mechanic, who didn’t have much faith on oil analysis, said, ‘Don’t worry about it,’ and the owner just kept checking it periodically and all of a sudden he found a bad exhaust valve leak on one cylinder. When they pulled the cylinder they found that the wear between the valve stem and guide was so great that it had about 3/16 of an inch side-play in it, so he was getting ready to drop a cylinder. That’s just one of those that didn’t really give us enough trash to hang our hat on, but something didn’t look right.

Does the FAA supervise oil analysis? Do you have a repair station license?

Years ago I went for a repair station number in St. Louis, and they had no idea what I was talking about, so we just dropped that. There is only minor FAA supervision.

I have had customers take my reports to the engine manufacturers, and in some case they will agree and occasionally with disagree. None of them specifically bless oil analysis, but Lycoming’s SL171 addresses it.

I have never said that oil analysis is a stand-alone service. Oil analysis and filter or screen inspection go hand in hand.

Did Engine Oil Analysis do filter analysis, too, or was that done in the field by the A&P?

People sent us filters — it wasn’t uncommon to get a segment of a filter in along with an oil sample with a request that we look it over. Now I have a company called SECOND OilPINION, and we do inspection of filters, or the washings out of screens. Then we send a report back to the customer, owner or shop as to what we found and usually we’ll give a statement as to whether or not we think it’s excessive for the time on the engine and oil.

What’s your advice for getting an engine to TBO?

The first thing is to fly it. Fly your engine, and odds are the rest of the airplane will come along with it. After that, oil changes not to exceed four months. Whether you’re a on a 25-hour or 50-hour interval, you shouldn’t fly your oil more than four months. You’ve got moisture in there, and some of that moisture’s going to be in the form of an acid, and that’s going to cause problems.

Air Godfrey makes it to TBO
I also don’t believe in going out and doing periodic run-ups where you don’t fly, because you just generate another big condenser. And don’t go pull the prop through — you’re not going to put any more new oil up there, and you’re just scraping away what little residual oil is there.

The engine should burn some oil. Continental had a tremendous problem with some cylinders that did not burn any oil, and they simply did not lubricate the upper cylinder. As a result, they replaced a lot of cylinders, and got that problem whipped to where their engines were back to consuming some oil in the upper cylinder. If you don’t get some up there, you’re not going to lubricate it and the barrels. That’s another wear metal characteristic you could spot, and you could tell the owner what to look for in a Borescope inspection. Usually they’d come back to you and say, ‘Yes, we found polishing at the top of ring travel,’ so you know that you had a dry upper cylinder.

Can you spot a glazed cylinder wall with oil analysis?

No. Usually glazing is manifested by high oil consumption, and I’ve seen guys try to go back and try to run some more mineral, but that’s just a long shot if it works. Usually you’ve got to pull the jug and rehone it, and break the cylinder in properly.

Is there one brand or type of oil you like better than the others?

No, I think all of them are making good oils. The best recommendation I can make on oil is use what your engine manufacturer or your overhauler recommends, and use what the individual owner thinks is best for his engine and operating conditions.

What was your first clue that something was wrong with Mobil 1?

We were seeing Mobil 1 engines that would have real good wear metal profiles, and then all of a sudden things would start up — no particular break in the profile, just everything would start up — and we believe that’s when those engines started to develop sludge. But that was a short-lived situation. Mobil bit the bullet on that right quick.

What’s your opinion on oil additives?

Our study on Av Blend disclosed no measurable benefit. We heard from a lot of people who used it and said they were going to keep using it, and most of those testimonials came from small bore Continentals — 0-300 and 0-200 Continentals — where the guy said the AvBlend seemed to stop their valve sticking. As far as a measurable benefit, I spent two years developing the data and I never did find anything.

I am not an advocate of snake oils, and I’m not an advocate of becoming a crankcase chemist. When you pour this stuff into an engine you’re taking a manufacturer’s advertising agency’s word for what it’s going to do when it mixes with the oil that’s in there. I think you’re crazy.

Marvel Mystery Oil is mostly solvent. You pour it in your crankcase and you get diluted oil. The solvent flashes off at a couple hundred degrees, so it hadn’t really done anything. STP is a viscosity index improver, so it thickens the oil. The Teflon stuff is a joke, but lots of people have made lots of money telling you that you can put Teflon in your engine.

The oil companies spend tons of money to develop the best oil that they can develop to meet the specifications of those engines, and then some guy over here with a race car in his backyard and a couple of buckets in his garage starts selling this stuff that he says makes his race car run better.

I make an additive right here in Tulsa. It’s highly refined cattle manure from the yards out in the Texas panhandle. We only use Texas panhandle feedlots to get the raw material, and we blend it with a solvent material that will flash off real fast — we get that out of the bathtub faucet. It’s $19.95 a quart and we pay all shipping and handling. You pour it in your oil, and we don’t know what it’ll do and we don’t really care — we got your $19.95. I call it BSIAB — bullshit in a bottle.

Phone or fax SECOND OilPINION at 918-492-5844