Labratory oil testing

[hotel hobo]

My questions apply to piston engines however turbine feedback is welcome.

I am considering having engine oil sent to the lab for analysis.

Does anyone have any experience with this?
Does it work as claimed?

My understanding is: they can trace metals, to any wetted engine part in advance of evident problems. Possibly used for diagnostics??

Excuse my ignorance if this is regular practice. However if it isn't, might someone have a practical example of how it was worth the money?

Thanks in advance,

HH

[GARTHRYAN]

Hi Hotel Hobo. I only have TFE 731 oil sample experience, but we send in oil samples every 150 hours. It is most definitely worth it. My best example of it working is, we had been contacted by Honeywell to perform a re-samaple right away after a routine sample. So we sent the re-sample in and they came back right away and told us the exact bearing that was starting to come apart. When the bearing was removed the material missing from the bearing was so minor, I couldn't believe what it picked up.
Garth

[The Weasel]

Yes, on some of our a/c types (AS 350, turbine engine) we take engine oil samples for analysis at every 100hr inspection. It's never happened on an a/c I was working on, but once in a blue moon one in the fleet will come back with a bad sample analysis or perhaps showing a bad trend of increase in whatever contamination, and an engine gets inspected/replaced. I don't know the cost of doing the oil analysis, but I imagine even with 17 a/c of this type in our fleet over a period of many many years, it's still cheaper/more convenient than having a million dollar engine let go in flight.

As Garth mentioned, they can be quite quick and accurate in their oil analysis.

I vaguely remember there also being some kind of small cost benifit to the company from the engine manufacturer if such samples are taken (ie: warranty or something like that), but it may be specific to this engine or manufacturer (Turbomeca). They may want the sample for their R&D.

[cgzro]

I used to do them religiously when I first owned my aircraft. They were quite normal for a year and then I got a spike in iron. The engine continued to run normally and my mechanic just said to keep an eye on things, the iron would spike up and down a bit but was always a bit abonormal. During that time the oil screen was squeeky clean.

Then all of a sudden the oil screen started to show small shards of iron .. which got progressively worse and worse, about that time the iron content stopped being abnormal So I suppose the oil analysis was showing me that something would soon happen but once it did start to happen it was obvious from the oil screens.

The death blow was when I started to get serious plug fouling and of course the lifters had been dropping little shards onto the piston skirt which then scratched the cylinder walls etc. So the analysis was definitely a heads up, but the engine did not need to be pulled for nearly 100hrs after the iron spiked, at least there was no hard physical evidence so it was very difficult to make any concrete decision based on abnormal iron until there were other symptoms. This may be an easier call in a chopper or something flying hard IFR.

[Rudder Bug]

I sent oil samples twice to Blackstone Labs and I’m really happy with it. Here is the type of message you receive a few days after sending your oil, plus the detailed report of the elements in part per million found, and a chart (which I am unable to paste in here) of what they should be :

GILES: High wear and silicon are both common finds in new engines such as this. The wear is high due to
break-in of new parts, while silicon is from sealers and sand-casted parts. Universal averages show typical
wear metals for an oil sample from an O-320-A1A after 35 hours use. We suspect this engine will look that
good, if not better, soon, though nickel may never drop all the way down to averages due to the cylinder
type. It should steady out, though. A little fuel was present and this may disappear as the rings seat. Stay at
15-25 hours to monitor.

Sent another sample 25 hours later and got that:


GILES: The total engine hours threw us a curve at first when we compared it to your first oil sample. We
assume this engine was rebuilt a short while ago and most wear metals decreased this time. Nickel should
drop some more next time. The odd one was copper (brass/bronze parts), which was higher mainly due to
the use of A.S. 15W/50 that reacts chemically to the cam coating in Lycoming engines. That reaction shows
up as higher copper in the oil. Silicon looked better showing normal air filtration. Insolubles were low
indicating excellent oil filtration. Check back.

It is a very well invested 25 bucks!

http://www.blackstone-labs.com/

Giles

[niss]

I use Diagnostic Oil Analysis in Acton, every 25hr during my oil change.

[Heliian]

S.O.A.P's can be helpful but are usually only done when it's made mandatory. eg. the AS350(arriel engine) requires a soap sample every 100 hrs or you have to tear apart the rgb every 500hrs, so by doing the check you save time and money. Just doing it for the sake of doing it is great, but unfortunately in the GA world people have no clue about preventative maintenance. Spend your money on something more useful as the chances of a SOAP program finding problems before you do are slim. Change the oil at the recommended intervals and don't go to the cheapest AMO, go to the one that does good work, it's not a car we're talking about here. The lycomings i've worked on had enough problems, don't need lab samples to tell me an exhaust valve is blown or a jug is cracked.

[SeptRepair]

Change the oil at the recommended intervals and don't go to the cheapest AMO, go to the one that does good work, it's not a car we're talking about here.

Um, changing the oil and filter has got to be the easiest job to perform on an aircraft, actually easier than on a car.

[LousyFisherman]

Um, changing the oil and filter has got to be the easiest job to perform on an aircraft, actually easier than on a car.

Yeah except for the little twisty thing (lockwire)

Partnership all amateur pilots, we send our oil for analysis every change (50 hours)
Filter: $30
Oil: $40
Testing: $20

Cheap at the price.

LF

[niss]

Yeah except for the little twisty thing (lockwire)

Just stick a hair pin in there and you're fine.

[Heliian]

really, bring your p.o.s. plane to a jiffy lube then, but at 100hr they usually need a little more than just an oil change. Most private planes are in serious need of repair and even some commercial ones (usually FTU's). It breaks my heart to see a nice old cessna just rotting away outside, then the owner shows up, finds out it won't run and then bitches about having to pay for new mags or starter or jug or whatever. Take good care of your equipment and it'll take good care of you, if you want to spend the extra for Soap go for it, but just make sure you do it consistently, that's the whole purpose of trend monitoring, it's not a one shot deal.

Cheers

[niss]

really, bring your p.o.s. plane to a jiffy lube then, but at 100hr they usually need a little more than just an oil change.

Was that directed at me?

[Heliian]

No, sorry bout that, I'm stuck in the bush and have way too much time on my hands, kinda got off topic. I was just refering to the cheapskates who want their plane serviced for 60 bucks an hour when you can't even get your car serviced for under 80 an hour. Obviously the guy who's on a SOA program cares more than the average joe.

Keep it shiny side up.

I

[niss]

Obviously the guy who's on a SOA program cares more than the average joe.

Keep it shiny side up.

I

That's right, I am a Super Owsom Aviator, thank you for noticing!