Why I Like Oil Filters and Oil Analysis

[GA MX Trainer Dude]

Company sent me to Yellowknife to perform an inspection on an Aero Commander 690 before it left on a contract starting in Fairbanks Alaska. Since I had friends in Fairbanks I made them a deal that they provide my return ticket from Fairbanks a couple of days after the aircraft was positioned there. That way I could visit my friends – look around a bit – and return home – a win / win for everyone.

Flew into Yellowknife – did the inspection on the Garrett Grenades – sent the oil samples away to Calgary for processing – left for Fairbanks after inspection done and overnight for rest.

About half way to Fairbanks we received a radio call (Company HF) – the company doing our oil analysis had come up with a possible imminent failure of the right hand engine based on the results of the oil from that engine. It had looked fine to us when we did the inspection which included a “Feel Test” that I always do to check for any grittyness in the oil that could be felt but not seen. The oil analysis was a requirement for this engine so was just done automatically.

We shut down and feathered the engine and carried on to our destination. Once there I pulled the filter on the engine and found a substantial amount of “Fines” in the filter. I checked later when we drained the oil from the engine and there were no fines in the oil which meant the filter had trapped them.

The engine shop report came back with a comment about the engine being on the verge of a mechanical failure of the gearbox due to a spalled gear. Their estimation was that about 20 minutes of continued operation would have finished off the engine. As it was we caught it in time – the overhaul costs were very reasonable compared to buying a new engine.

You can pay for a lot of filters, inspections, and oil analysis for the cost differences as well as damages done when the engine mechanically fails.

We still changed all the hoses, feathering pump, prop, oil cooler, fuel heater etc. just to be sure we got all the possible metal out of the engine, prop and systems.

There is a reason filters are installed on aircraft engines!!! This one did the job it was supposed to do and saved the rest of the engine.


Since I was already with the airplane, I got an extended stay – changed the engine in a nice warm hangar – saw my friends – made some new ones – had a good look around – and flew home commercial.

Mx

[Colonel Sanders]

One of my engines, I have been flying for 42 years
now. No oil filter installed by either the engine or
airframe manufacturer. No problem.

All around me, I see casualties of crappy oil filter
conversions. If it ain't there, it can't break, son.

Look up cost/benefit analysis sometime.

[crazy_aviator]

Im a proponent for Oil filters,,,, Colonel, when was the last time you saw a screen on an auto engine? Want dirty oil with metal bits BACK into the engine oil galleries to do their job of grinding down the engine ? Thought so,,

[GA MX Trainer Dude]

Colonel

One of my engines, I have been flying for 42 years
now. No oil filter installed by either the engine or
airframe manufacturer. No problem.

I am very glad you have had such good success with this engine!!!
That is a good long life - but I question whether the lack of an oil filter has any bearing on the longevity.

All around me, I see casualties of crappy oil filter
conversions. If it ain't there, it can't break, son.

Maybe you should change who you hang around with!!!! (It's a joke - so don't get pear shaped.)

Look up cost/benefit analysis sometime.

IIRC - The 690 engine overhaul after the inflight shutdown cost the company about $ 26,000.00 as opposed to an overhauled outright engine purchase of about $80,000.00. Those numbers are from a while ago so they would be higher today.

That represents a pretty good cost / benefit ratio to me!

In addition - having parked my butt in the right seat for the trip - the minimal cost of a miserly oil filter / oil analysis program was also a pretty good benefit from my point of view.

The fact that the filter captured the metal fines and held them from circulation - something that a simple screen is not going to do - is what the item was installed for to begin with. There are strainers in the engine as well. In this case the next indication that would happen is a filter impending clog indication on those aircraft that have the technology. Another good step in the engineering process that makes very good sense. In addition when the fines build up sufficiently on the chip detector the indication system on those aircraft that have it would illuminate and let the flight crew know they have a problem.

If it ain't there, it can't break, son.

My quote for the day "If it ain't there, it can't help you, son"

If we throw out the oil filter - might as well dump the rest of the indicating stuff too!!

In your case with your long lived engine should a similar fate befall it you will have no protection whatsoever because by the time the strainer collects the large lumps your engine will be toast. Then you can do your own cost/benefit analysis. I really hope you run that engine with a chip detector, with in cockpit indication, so you have an idea of an impending failure before it happens - otherwise IMHO - you are not looking at the risk / safety analysis very closely.

There is the KISS principle that is very well known and is / should be a guiding rule for all engineering designs. If you are seeing a lot of failures in the aftermarket installations then that is only a very small segment of the industry as a whole. I don't think you would ever change a commercial design engineers' mind regarding not putting an oil filter on an engine. I think the common term for this is "Throwing the baby out with the bath water"!!

If the problem is confined to the add on STC oil filter installs, then rant at that issue - not at all of the oil filter installations on aircraft engines.

Fly safe.

Mx

[Colonel Sanders]

I don't think you would ever change a commercial design engineers' mind regarding not putting an oil filter on an engine

Yup, you certainly won't change mine. This engineer
doesn't believe that they pass a cost/benefit analysis,
and what I do to my engines would blow your mind.

[GA MX Trainer Dude]

Colonel

Yup - Guess your mind is made up - so I shall refrain from further confusing you with any more facts.
You are entitled to your opinion and I am just as entitled to mine.


Pick Whichever one works for you Colonel.
http://quoteinvestigator.com/2013/02/13/confuse-me/




Mx

[Colonel Sanders]

I somehow doubt that you have ever performed
a cost/benefit analysis. Sometimes the results
are quite counter-intuitive.

Here is a simple - and hopefully illuminating - example,
from a long time ago.

There once was a company called Ford, which made
cars. Not very good ones, frankly. One of their pride
and joys was called the "Pinto".

The Pinto had a little engineering problem. When hit
from behind, the rear shock absorbers would puncture
the gas tank and spill gasoline over the unfortunate
occupants of the rear seat, whom would generally be
incinerated. Not a nice way to go, frankly.

Ford learned about this problem, and ran the numbers.

They figured that over the life of the Pinto, if they did
nothing, there would be X accidents, and each accident
would cost the company Y dollars in legal costs.

So, the "do nothing" option cost X times Y = Z dollars.

The engineers invented a shield, to prevent the gasoline
from spilling forward. To issue the recall and install the
fix would cost A dollars for each car, and there were B
cars in the fleet.

So, the "fix it" option cost A times B = C dollars.

Now, the reptilian sociopaths running the corporation
noticed that Z was less than C. Fixing the problem and
preventing more customers from being burned alive was
actually more expensive than doing nothing.

Which option do you think the company management
chose? Of course, the "do nothing" option.

Does their decision make sense to you? Probably not.

I shall refrain from further confusing you with any more facts

No really, I love your charming anecdotes in which you
ride charging in on a white horse to save everyone at
the very last minute, spanner in one hand, soldering
iron in the other.

Can you tell another?

[GA MX Trainer Dude]

CS

The Ford psychopaths in control made that a no brainer in regards to the "MONETARY" COST vs BENEFIT.

There is more to the cost / benefit equation than simple DOLLARS.
They lost the plot on moral grounds and should have all been jailed IMHO.

So "No" - I was not surprised when told of this soooooo many years agoooooo.

See - sometimes we agree on things!!
(BTW - be careful as to what you assume about me - you might be surprised at just what level of knowledge I operate at.)


Mx

[NeverBlue]

C'mon Colonel you know darn well that would never happen today. My car was recently recalled for a simple brake switch. 1.5 million cars in total...cost effective?

[Colonel Sanders]

The point was that sometimes, a thorough
cost/benefit analysis can yield astonishing
results, that at first don't make sense.

Do recall what Bill Lear said

[GA MX Trainer Dude]

The great Bill Lear said a lot of things.

One of the best one-liners I ever heard was his reply to a prospective buyer saying "That he couldn't stand" in the early Lear-jet.

Bills' reply - " I don't stand in my Cadillac either!!"


Also I am pretty sure I never heard Bill say - "Take those Damn oil filters off my engines".


Mx

[Colonel Sanders]

No, but he did say,

"Simplificate and add lightness!"

It doesn't make sense to add oil filters to every
engine, despite your religion.

[NeverBlue]

I think in his example it does. What would have happened if that filter wasn' t there?
Would that garret have even made it to the HF call?

[Colonel Sanders]

http://en.wikipedia.org/wiki/Proof_by_example

It's important to know the difference between
religion and logic.

Proof by example (also known as inappropriate generalization) is a logical fallacy whereby one or more examples are claimed as "proof" for a more general statement.

This fallacy has the following structure, and argument form:

Structure:

I know that X is such.
Therefore, anything related to X is also such.

[GyvAir]

would be X accidents, and each accident
would cost the company Y dollars in legal costs.

So, the "do nothing" option cost X times Y = Z dollars.

The engineers invented a shield, to prevent the gasoline
from spilling forward. To issue the recall and install the
fix would cost A dollars for each car, and there were B
cars in the fleet.

So, the "fix it" option cost A times B = C dollars.

Now, the reptilian sociopaths running the corporation
noticed that Z was less than C.

Sounds remarkably like Ed Norton's character in Fight Club.


On oil filters and analysis though.. it's horses for courses. Analysis is a waste of time on most piston engines and many turbine engines as well. One engine I'm all for it on is the Garrett that the original post was about. The heads up giving you the ability to avoid changing that engine on the ramp in Tukayawhereyadunwannabe is all the cost benefit analysis I need, saying nothing of safety considerations.

Gimpy aftermarket oil filter installations; not a fan. Good ones; ok. But, as CS pointed out in his earlier thread - correctly, I believe - misuse and disuse will kill an engine faster than any oil filter can save it.

[crazy_aviator]

Colonel, Im going to make this as brief and as painless as possible. I own an A/C with a FACTORY installed spin-on oil filter assembly on my 0-320 E2D Its a breeze and painless to pull the filter and examine the material for impending disaster ( Positive cost-benefit analysis #1) These factoy installs are NEVER a problem. The Original strainer and housing on the 0-320 series are a pain in the BUTT!! Ears cracking on the housing, leaks, improper torquing ( by the last person) stripped threads in the case ( Negative cost-benefit analysis) NOT to mention the inability to properly examing ALL the small to minute particles that the filter catches ( Negative CBA #2)
And last but not least, The spin-on filter catches almost ALL the particles that would otherwise recirculate,,,WEARING the engine and COSTING a shit load more at overhaul ( PCBA#2 ) Are you getting it now Kernal ?
The main difference between a cult and a non-cult is that the cult thinks it is right and everyone else is wrong ! Are you in a Cult Sanders?

[GA MX Trainer Dude]

Colonel Sanders

No, but he did say,

"Simplificate and add lightness!"

It doesn't make sense to add oil filters to every
engine, despite your religion.

My lawnmower doesn't have an changeable oil filter - I am OK with that - it isn't expensive to replace a mower, and I don't depend on it to keep my butt in the air - so your religion crack is in error.

Donald Douglas is quoted as saying "Let's build an airplane that won't give the guys trouble".

After the company was bought by McDonald the company religion changed to "Do more with less."

The Douglas directed engineers that did the original door design used hydraulic locking actuators for the cargo doors on the DC-10. McDonald Douglas after the takeover had a program that paid out a thousand dollars for every pound of weight saved. So the original cargo door locking actuator design was changed to the lighter and simpler electric actuators. We all know how well that worked out don't we. Simple, light, and deadly because unlike the hydraulic actuators that would bleed off fluid by the pressure relief valve and allow the cargo door to open when the actuator was not correctly rigged and did not go into the over-center position. The slight opening of the door would do two things - first it gave an indication in the cockpit of an unlocked cargo door and second the movement of the door was such that it opened a big enough hole in the side of the aircraft that the pressurization system could not build up enough pressure to blow the door out the side of the airframe. The electrical actuators were based on an irreversible system (screw jack) and when not in the correct over-center position would transfer the load from pressurization into the actuator attachment fittings. Since the actuator was irreversible the pressure built up as the aircraft climbed and at some point exceeded the design strength of the actuator resulting in the total loss of the cargo door without any indication to the flight crew of an unlocked door condition until said door departed. The 3rd accident resulted in the loss of the entire aircraft and over 300 people - the second accident was saved by a super pilot who landed the aircraft in Windsor Canada after a takeoff from Detroit. The first accident was while the aircraft was undergoing air conditioning and pressurization trials at the factory. Once again "Monetary considerations compromised flight safety." (And yes I know the electrical actuators work just fine if the are over-centered correctly when the door is locked - Hmmmmm - much like a correctly installed oil filter will do its' job and not leak or make additional metal if it is correctly manufactured and installed.)


So I am pretty sure my friend Bill also never said - "Oversimplify and reduce weight to the point where safety may be compromised."

Weight saving??? A filter is probably less than 2 pounds - but if what you say is true why then didn't the super smart engineers remove the oil filters from the 3 engined DC-10 - some smart genius could have made $6000.00 with that modification - and maybe an extra $1000.00 for the APU?? Wasn't done and hasn't been done simply because oil filters are a proven engineering design feature.

Over simplification I don't think is an issue here - a spin on oil filter is a pretty simple bit of gear. The removal from the engine housing filters are maybe a bit more difficult, but again not something that is rocket science for the average AME. The most labor intensive ones that I worked with were the stack type aircraft oil filter assembly as found inside P&W R1830 etc. These were designed in the 1920s and were easy to inspect, clean, and re-assemble in the field with a minimum of tools and equipment. If you were stuck you could even use your toothbrush to clean them.BTDT You had to count the number of element plates and assemble them in the correct sequence, install the retainer, torque, and then measure the length to ensure the elements had not crushed. The assembly was then lockwired, installed (Only one way it fit), put the cover plate on with a new gasket (4 ways for it to fit - only 1 right way that was easy to tell), and leak check by running the engine.

So if that range of difficulty is overwhelming you then have somebody with the necessary skills perform this arduous task for you - oops I forgot you don't have to do this because you took them off. I presume that the extra time you save by not looking at a filter can be put towards -

what I do to my engines would blow your mind.

I presume that quote is describing how you fly them????

It's important to know the difference between
religion and logic.

Quote:
Proof by example (also known as inappropriate generalization) is a logical fallacy whereby one or more examples are claimed as "proof" for a more general statement.

This fallacy has the following structure, and argument form:

Structure:

I know that X is such.
Therefore, anything related to X is also such.

If I read correctly what you have offered up as a logical argument for why I like oil filters and oil analysis, then you my learned friend have just hoisted yourself by your own petard!!

By your own admission you claim that in your opinion: X (Oil filters) cause more trouble than they are worth - therefore anything related to X (Oil Filters) is also such. So that would mean that oil filters, oil analysis, chip detectors, and of course no need for impending bypass / clogging filter annunciation systems, etc. also cause more trouble than they are worth. Your "Oil Filter Religion" is blinding you from a simple concept - they do in fact (by decades of proof) work for the majority of applications.

"Proof by example"

- I think you missed the boat on this one. There are an overwhelming number of examples of how oil filters help keep the engine oil free of contamination. - Your little sample of proof that you have observed doesn't amount to diddly squat in the large picture. It might be a good sample for your specific type of engine / oil filter installation but I don't think I would be looking to change what is already a proven engineering process for the rest of us.



(BTW - I don't ride horses - so can't ride in like a white knight to save the day. I am more likely to be using a computer connected to an airplane these days and reading fault codes than riding around with my soldering iron (I hope you gave me a butane one so I don't need a cord) and a wrench!!)

Happy wrenching and soldering guys

Mx

[Colonel Sanders]

Ever had an oil hose start to leak as you flew
single-engine across the Gulf of Mexico?

Remember you get two extra hoses when you
install that crappy aftermarket oil filter. And
that crappy adapter plate that bolts on where
the pressure screen housing was - I have seen
them crack and drain all the oil out of an engine
in flight.

None of the engine/airframe manufacturers saw
fit to install an oil filter on any of my airplanes. I
think I'll go with their judgement - not yours.

You keep flying your airplanes your way, and I'll
keep flying my airplanes my way, thank you.

You'll have to pardon me if I don't drink your Koolaid.

[dashx]

CS.

When it comes to oil filters obviously you have a love/hate relationship.

But please keep on grinding water.......

[Big Pistons Forever]

My 02 cents

I think there is a middle ground here. If the engine came with a factory installed oil filter and you have been running it with the filter I personally do not see any reason to remove it, and has been pointed with some engines you do not get the choice.

Where I would suggest there is room for debate is a situation like mine. When we bought my AA1B it had 1600 hrs on its Lycoming O 235 engine. We looked at putting an aftermarket remote oil filter (there is not enough room to put the stock Lycoming oil filter assembly on the back of the engine) and since the engine was already pretty high time the expense did not seem worth it.

However If I had to overhaul it I would have it modified from the current 108 hp 80/87 version to the 118 hp 100 octane version. This requires that you add an oil cooler and one option is a unit that is both a cooler and has a oil filter adapter. This is the option I would choose as you cooler or not you still have a remote unit with hoses and you do get the advantages of filtering the oil which in this case I personally feel out weigh the disadvantages of an oil filter failure.

Like most things in aviation oil filter "Good" or "Bad"; resists easy one size fits all solutions and therefor IMO the choice needs to be made on an individual basis considering all the factors that apply to your particular situation.

[GA MX Trainer Dude]

Colonel

Ever had an oil hose start to leak as you flew
single-engine across the Gulf of Mexico?

Hey I can go one better than that!!!!

Ever had a prop governor break 3 out of the 4 bolts while on a flight from New Orleans to The Caymans??

Yup there we were - fat dumb and happy - in cruise with the old pigboat heading to Chile to fight fire when I get the call to come forward and slide into the right seat. Very unhappy Captain points to the left engine as I put on my headset. "Looks like an pretty bad oil leak from the prop governor." is what he said - the "Do you want me to feather it?"

So you want to talk a bit about risk analysis - hydromatic propellers when deprived of their oil will revert to the fine pitch stops and without governor pressure will overspeed first and then quickly runaway - fling blades - or in some cases when the engine seizes the inertia of the spinning prop mass rips the prop and / or engine right off the airplane. So the thing to do by the book is to feather the engine and fly single engine to your airport of choice. (See the DC3 crash thread in accidents forum)

Since we were doing long legs we had pretty much full oil tanks,---- so as long as the oil didn't catch fire ---- we could probably make it back before we exhausted the oil - but there was a fire hazard that we had to accept if we did nothing. So all the conditions except one said the decision to feather the engine was the right one.

The exception was that something was bothering me about the prop governor - what I realized was that it was rocking on the drive pad which meant the hold down studs had failed. The captain wanted to feather it but I said no - and explained that the operation of the feathering pump would supply oil to the propeller governor under more pressure than the governor was currently and that by activating the pump we risked the chance of blowing the prop governor completely off the engine with no way to control the propeller from that point on.
So we turned around and nursed the old girl back to the airport - the governor stayed attached - but we also didn't touch the prop controls for that side until we had landed. We went through about half of the oil supply - the airplane looked like hell - but we were safe. Inspection of the propeller governor hold down studs showed overstress cracking on 3 of the 4 studs. There was a logbook entry some 2 months before that the governor was leaking and the solution was "Hold down nuts tightened - no leaks found". What should have happened with the snag is that the propeller governor base gasket should have been changed and the hold down nuts tightened to the correct torque.

So some jerk who thought he knew something about how to fix a problem made things worse. - We changed out the studs - inspected the drive spline for wear - it was good - installed an overhauled governor - adjustments made. and off we went the next day.

In the end it was a good risk analysis although the fire risk was very high we felt it was better to take that risk than have a runaway propeller. You might have decided to do something different.


So Yes Colonel Sanders I have been in sticky positions more than once and I know exactly how you would feel!!

As I pointed out in my previous remarks your experiences with aftermarket STC installations of oil filters has not been positive.

I have indicated that I agree with you on the removal of those oil filters in the case where the original engine didn't come with one.

No issues with that concept - TAKE EM OFF!!!

None of the engine/airframe manufacturers saw
fit to install an oil filter on any of my airplanes. I
think I'll go with their judgement - not yours.

I do not have an issue with this statement!!!!
It is your airplane - but if you should ever crash into my house and the cause of the crash was preventable by the installation of an oil filter; rest assured that I will come after you with all I have. You on the other hand are going to have to defend yourself with the argument that you took off a piece of kit that would have helped because you deemed it unsafe to use by your experience. Should make for an interesting court case my friend. At the end of it you might win simply because the outdated standard to which your engine was manufactured to is still the "LEGAL" and conforming document and thus you would not be operating in contravention of the regulations. But sometime there are better alternatives to old technology - and sometimes the so called "Approved" addition of technology is not a step in the right direction.

This is where I see your concerns and they are valid concerns for these engines only!!

Just don't try and convince the rest of us that since these ones are bad; that all of them in every aircraft engine should be removed.

You keep flying your airplanes your way, and I'll
keep flying my airplanes my way, thank you.

I think that that is probably about as close as we are going to get on this issue.

You'll have to pardon me if I don't drink your Koolaid.

And I think that is in pretty bad taste. (pun intended) - but funny considering the source.


Stay safe

Mx

[photofly]

It is your airplane - but if you should ever crash into my house

We need to know where your house is for a proper risk analysis.

[Colonel Sanders]

Actually, there's a house in Ottawa just below the
localizer for runway 7, that's been hit by blue ice.

Twice.

Now, that's impressively accurate.

[GA MX Trainer Dude]

photofly

We need to know where your house is for a proper risk analysis.

16 Kms to nearest airport - not in alignment with runways or under the normal traffic pattern and well hidden in the trees.

The approach to the local hospital is closer - about 3 Kms - also not on the usual traffic pattern though I can often see the helicopter coming and going.

So I would consider it a low risk for impact for your risk analysis. I would expect a helicopter crash before a CS oil filter-less crash.


Now a previous residence in Richmond would be completely different - just offset from the approach - about 3kms from the end of the runway. That one I would have to say would be high risk for your impact analysis.

This thread has been fun - seems I miss my daily "Aviation Fiber" when I am on time off - (For good behaviour I should add).

Mx

[sidestick stirrer]

"Now a previous residence in Richmond would be completely different - just offset from the approach - about 3kms from the end of the runway. That one I would have to say would be high risk for your impact analysis"

Was that your place with the large, white letters on the roof, letting all who happened to glance down and to the right while on short final for 26R, know how you felt about YVR?