Departure Emergency - Challenger Oil Filter

[Shadrach]

5 hours ago, alextstone said:

Thanks to all of you who have posted such thoughtful experiences and advice.  Last night I filtered the oil and cut open the filter after one hour of run time.  I did not have time yet to pull the oil screen.  Here are some photos of the metal flakes I found.  Sorry about the poor quality of the photos. I'm certainly no impression from looking at them is that they look like the same alloy as that of main bearings.  In total, there were perhaps 5-6 flakes in the filter and the same number captured in the filtered oil.  

 

 

 

i 

Ferrous or non ferrous? I expect that you will find more in the screen.  

This is not me rendering an opinion on the engine’s health, just putting things in perspective.  Given that you own the shop that installed the filter, it would seem that the labor would be at cost. Removing the prop and engine should ~12hrs. Pulling cylinders, breaking down the bottom end should be about the same. That’s what it’s going to take to fully investigate. Reassembly will take considerably more time than disassembly. Nevertheless, at cost, you could likely IRAN the whole engine for 10-15k depending on how far you want/need to take it.. 

Unless the cylinders are perfect, they should likely be sent out for IRAN while they’re off.  If you don’t have a local cylinder shop I have a local shop whose work and pricing I would put up against any facility in the country. 

[alextstone]

42 minutes ago, Shadrach said:

Ferrous or non ferrous? I expect that you will find more in the screen.  

This is not me rendering an opinion on the engine’s health, just putting things in perspective.  Given that you own the shop that installed the filter, it would seem that the labor would be at cost. Removing the prop and engine should ~5hrs. Pulling cylinders, breaking down the bottom end should be about the same. That’s what it’s going to take to fully investigate. Reassembly will take considerably more time than disassembly. Nevertheless, at cost, you could likely IRAN the whole engine for 10-15k depending on how far you want/need to take it.. 

Unless the cylinders are perfect, they should likely be sent out for IRAN while they’re off.  If you don’t have a local cylinder shop I have a local shop whose work and pricing I would put up against any facility in the country. 

Yeah, trust me, I'm not flying it again until we do just that or a compete overhaul. I'm researching my options as to whether and to which carrier a claim should be submitted.

[Shadrach]

On 9/20/2022 at 10:22 AM, alextstone said:

Yeah, trust me, I'm not flying it again until we do just that or a compete overhaul. I'm researching my options as to whether and to which carrier a claim should be submitted.

I would not submit a claim out of the gate. The cost to investigate is meager.  Slow your roll until you know what the actual damage is. I can’t imagine that filing after the engine is open will make a difference. Maybe that’s the first thing you should check. The second thing to investigate is wether your insurance company will subrogate against Challenger. It’s clear that there’s a manufacturing problem with the Challenger filter.  I’m sure if your A&P had to do it again he would take great care to orient the extra O-ring material around the circumference of the filter to give it the best chance of holding under pressure. The thing is, he shouldn’t have had to. That O-ring is not properly fitted to the filter.

[alextstone]

I would like to pause for a moment and thank all who have participated in this thread and on this forum in general.  I have and continue to rely on your collective expertise to guide me to become a better, safer pilot and maintainer of my aircraft.  Your input is greatly appreciated.  I feel sometimes like I will be judged negatively from some of the information I share but each time I have those reservations, the responses are largely thoughtful, respectful and very helpful.  Thanks again.

[LANCECASPER]

6 hours ago, Shadrach said:

Ferrous or non ferrous? I expect that you will find more in the screen.  

This is not me rendering an opinion on the engine’s health, just putting things in perspective.  Given that you own the shop that installed the filter, it would seem that the labor would be at cost. Removing the prop and engine should ~5hrs. Pulling cylinders, breaking down the bottom end should be about the same. That’s what it’s going to take to fully investigate. Reassembly will take considerably more time than disassembly. Nevertheless, at cost, you could likely IRAN the whole engine for 10-15k depending on how far you want/need to take it.. 

Unless the cylinders are perfect, they should likely be sent out for IRAN while they’re off.  If you don’t have a local cylinder shop I have a local shop whose work and pricing I would put up against any facility in the country. 

I agree about pulling the engine, especially after what he found, but 5 hours to pull the Bravo engine and another 5 hours to pull the cylinders? Not on this engine.

As a point of reference Lycoming paid shops 40 hours of labor just to do the Bravo conversion when they had that program to convert from an -AF1A to an -AF1B. The engine stayed on the airplane and the prop wasn't touched. The cylinders were changed and the new oil lines were set up. That's the easy part.  As an example just getting the drain lines on and off on this engine is a chore. (The first few conversions that shops did took well over 40 hours, but after they did a few some shops could get it done in 40. There is a definite learning curve on this engine. My mechanic (former Mooney Service Center Director) and I did the Bravo conversion on N134JF back in 2018 and it was a great learning experience for which I'm grateful to have witnessed/participated in. But now I can check that off my list. I wouldn't want to be a part of that again. I'll leave that to the experts. We weren't in any rush, took our time, but I would safely say that we had close to 80 hours by the time everything was right.)

I don't know how many hours this will take to remove the engine and prop to get it sent off for IRAN and then re-installed, but if it's a mechanic who hasn't done a few of these, I'd be surprised if it's less than 40 hours to do it all and wouldn't be surprised at all if it was considerably more than that.

But bottom line, lives are precious, whatever it is at this point it has to be done no matter who pays for it. This will not be cheap. It will be a couple thousand just for the V-clamps if they don't have any more re-torques allowed on them (2 re-torques allowed before they must be changed). If you figure the cost of r/r, iran, v-clamps, turbo overhaul, etc, etc, depending on how many hours TT it might make more sense just to O/H it or go Factory Reman. Also a good time to send the exhaust off if it hasn't been done recently. This might have been one of those times where remembering not to put the gear down, i mean forgetting to put the gear down  would have made sense. . . just kidding!!!. The good news is no one got hurt, engines are cheap in comparison to loved ones.

[Shadrach]

On 9/20/2022 at 12:14 PM, LANCECASPER said:

I agree about pulling the engine, especially after what he found, but 5 hours to pull the Bravo engine and another 5 hours to pull the cylinders? Not on this engine.

As a point of reference Lycoming paid shops 40 hours of labor just to do the Bravo conversion when they had that program to convert from an -AF1A to and -AF1B. The engine stayed on the airplane and the prop wasn't touched. The cylinders were changed and the new oil lines were set up. That's the easy part.  As an example just getting the drain lines on and off on this engine is a chore. (The first few that shops did took well over that many hours, but after they did a few they could get it done in 40. There is a definite learning curve on this engine. My mechanic (former Mooney Service Center Director) and I did the Bravo conversion on N134JF back in 2018 and it was a great learning experience for which I'm grateful to have witnessed/participated in. But now I can check that off my list. I wouldn't want to be a part of that again. I'll leave that to the experts. We weren't in any rush, took our time, but I would safely say that we had close to 80 hours by the time everything was right.)

I don't know how many hours this will take to remove the engine and prop to get it sent off for IRAN and then re-installed, but if it's a mechanic who hasn't done a few of these, I'd be surprised if it's less than 40 hours to do it all and wouldn't be surprised at all if it was considerably more than that.

But bottom line, lives are precious, whatever it is at this point it has to be done no matter who pays for it. This will not be cheap. It will be a couple thousand just for the V-clamps if they don't have any more re-torques allowed on them (2 re-torques allowed before they must be changed). If you figure the cost of r/r, iran, v-clamps, turbo overhaul, etc, etc, depending on how many hours TT it might make more sense just to O/H it or go Factory Reman. Also a good time to send the exhaust off if it hasn't been done recently. This might have been one of those times where remembering not to put the gear down, i mean forgetting to put the gear down  would have made sense. . . just kidding!!!. The good news is no one got hurt, engines are cheap in comparison to loved ones.

It’s true that the Bravo has a much more complicated set of pipes with which to be contended. My point of reference was actually removing an I/O 360 from an F model by myself. Now that I think about it I underestimated by about four hours. I think it took me about 8 hours to do everything that was involved in removal of the engine. I will edit my previous post accordingly

I dropped the engine at my shop at 11:30AM. They called me at 4:30 to let me know that the case been crated and picked up by the freight company.

[PT20J]

A few things I picked up in my Lycoming factory engine class.

1. Lycoming plain bearings are steel shells plated with copper, then silver and finally tin-lead for the bearing surface.

2. We examined a lot of bad bearings. Some were relatively smooth but worn down to the silver or copper layer. Some were deeply scored. Some had chunks of missing tin-lead (called "pick out"). So, there are different types of bearing damage.

3. Lycoming has a very comprehensive document regarding metal contamination and what action to take. https://www.lycoming.com/content/service-bulletin-no-480-f

4. Lycoming has a metallurgical lab and will analyze metal found in the engine for free.

Good job getting safely down and good luck with the engine!

Skip

 

[alextstone]

Oil screen

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[Marauder]

Oil screen

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That’s not a good sign. Have you laid it out on a paper towel to see what the individual pieces look like?


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[A64Pilot]

Look like carbon hopefully.

I would strongly advise saving all particles and sending them to Lycoming and ask their advice.

We would send metal flakes to GE and they would tell us exactly which bearing it came from and advise us on what to do, often it was increase inspection intervals for a short time, so using the manufacturers expertise is I think a good way to go.

[EricJ]

2 hours ago, alextstone said:

Oil screen

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Ew.   No bueno if it's metal.   Looks like too much to be carbon chunks, but I wouldn't go by a pic.

[Shadrach]

2 hours ago, alextstone said:

Oil screen

Sent from my Pixel 5a using Tapatalk
 

When was the screen last removed? I expected that we'd see particulate. Often find particulate in an engine that has not had a low pressure event. I assume you will be sending the pieces of to Lycoming?  Look forward to learning more.

If you pull the engine, I would be very interested to know how long it takes. 

[jetdriven]

Interestingly that engine running without oil pressure video, after two minutes the RPM started coming down pretty seriously.  

[carusoam]

Alex,

Thank you for sharing all of the details…

There is soooo much to be gained….

I especially like the engine monitor details…. 
 

There wasn’t much time to identify the problem and be on the ground… before anything terrible could happen… great aviating…!

Lots of bits in the screen… and a few metal flakes…

Be careful sending things out…

Consider splitting everything in half, and paying extra to insure/track the shipment…

It is too easy to have these important bits get away…

Once Lycoming receives the first bits… then consider sending more if they ask….

My O360 liked to make carbon bits and store them in the finger screen…

 

I Hope for better news as more details come about…

 

On MS… you are never alone… even in the middle of the night…!

So many similar situations everywhere…

We have mechanics…

We have shop owners…

We have shop owners, that are mechanics, and pilots….

… and somewhere around here, we have at least one metallurgist… 

… and a few guys that know something about rubber molding…

… and probably a dozen people that can hand assemble a complex engine…

… and don’t forget the guy that can set up the complex engine for fuel flow and oil pressure…..

 

Go MS!

Best regards,

-a-

[carusoam]

Important pirep for challenger oil filters…

In case somebody searches on the words pirep and oil filter… the brand name will bring them here…

Best regards,

-a-

[A64Pilot]

I think best to send them to Lycoming

But for normal diagnosing, first wash the particles with a solvent using filter paper

Carbon can usually be identified by crushing it, carbon will crush easily, metal won’t.

Aluminum will be quickly dissolved with muratic acid (pool acid) maybe 25% strength diluted with water

Tin which may look like aluminum will be dissolved much more slowly than aluminum in dilute acid, if it’s tin it’s more likely a problem as tin is babbitt or bearing material, especially if the silver bit has what looks like copper on one side

Ferrous metals of course stick to a magnet, very fine powder could be ring and cylinder wear especially on a new cylinder.

But I wouldn’t mess with these, call Lycoming and ask what they want you to do with them and send them in, just based on what you have shown, I’d be surprised if the said pull it right away, but they are the experts, I’m just some old IA.

But if it’s just the couple of flakes you posted in the filter and the suction screen, I’ve seen worse on aircraft in service, particularly the screen, very often it’s pretty much never removed when it should of course at least annually.

‘I’m sure we all want to hear the outcome as well it could happen to any of us.

[goodyFAB]

On 9/18/2022 at 2:08 PM, philiplane said:

Most engines will run for several minutes at high power, without oil pressure, before incurring damage. An engine at idle for two minutes could still be OK, and there are ways to learn this, short of a complete tear down. The normal procedure would be to refill the sump, and run the engine for ten minutes, verify you have correct oil pressure (at the same temperature and pressure as before, verify with engine data). Then drain the oil through a fine mesh screen, and examine the filter. If there was bearing damage it will show up right away with small flakes in the oil. If any bits are found, the next step is to pull a front cylinder and remove the rod from the crankshaft to check the bearing and journal. 

i agree with you. 

food for thought, air cooled v twin harley drag racing- i turn a valve diverting almost all oil pressure from the pump as to free up parasitic loss and run it for 9 seconds or so WOT 7500 for a hundred passes. im not killing engines faster than the guys running full oil pumps and pressures. funny, i just gave away a secret, hope none of you drag race air cooled push rod lawn mower harleys lol. my point is at low power settings theres a very good chance everything is just fine. test the oil, change the oil, test it again. (im sure you had anough somewhere to test no?

 

 

to the OP , im really feeling for you, im sure you will figure it out ! best of luck. 

 

 

*****i originally wrote this before i saw the carbon chunks and etc, you've got some good advice given, keep us posted !

Edited October 4, 2022 by goodyFAB

[alextstone]

I have an update to share that I think will be of interest.  First, have a look at the photo below.  It is a photo of the filter PRIOR TO the event. 

As you can see, the filter is seated fully.  If the mechanic did pinch the quad seal causing it to become displaced upon tightening, it is my assertion that this is due to a poor design and the manufacturer should mitigate the problem.  Unfortunately when I contacted Challenger and spoke with their CEO, she elected to have their attorney contact me and demand that I send the filter and seal to their chosen lab along with my aircraft to their chosen shop in their home state.  No offer was made to offset any costs.  

I elected to ignore this demand for a period of time during which I could determine what my damage, if any, might be.  I did the following:

1.  Ground run the engine for 1 hr.  Cut open and inspect filter and remove oil screen.  The deposits found in the screen were all carbon.  There were a few particles of non-ferrous metal in the filter.

2.  Fly the aircraft in VFR conditions for 5 hrs.  Cut open another oil filter and remove the oil screen again.  This time, no particles were found in either.

3.  Fly the aircraft for an additional 13 hrs for a total of 19 hrs since the oil addition after the event.  Drain the oil, cut open a third oil filter and send an oil sample to Blackstone for analysis.  Here is the result:

 

 

As you can see, it is a near perfect report and the trends are all in a positive direction.

Next, I borescoped each cylinder.  No issues to report.  Compression checks were attained.  all cylinders were 76-78 / 80.

At this point,  I consider this issue behind me although I will additional oil samples for analysis.

 

BTW:  As for Challenger, I will contact them to update them although I am very disappointed in their stance so far, I will also file an SDR with the FAA now that I have more data to report.  Lycoming will not analyze any samples that are from engines that are not currently in warranty so that was a non-starter.

For those of you who recommended immediate removal and teardown of the engine,  I hope my decision to go another route does not seem reckless.  I feel that I made the correct decision given my own personal risk tolerance and the data that was generated along the way.  Thank you all for your input.

 

[alextstone]

One more data point:  Here are borescope images of the cam lobe / tappet for the intake valve on the #3 cylinder:

 

 

In my last post, I failed to explicitly ask for advice.  If anyone has any feedback or additional thoughts regarding my situation,  I would appreciate the feedback.  

 

[takair]

Is it possible that there is another cause to this that is not related to the filter oring?  Maybe it was previously discussed, so apologies if I missed it. Is it possible that with colder oil the bypass did not work correctly and the filter was acting as a relief valve?  I had recently been talking to a friend who experienced this on an experimental that was full flow without a relief valve and the seal is what gave way. Could the stuff in the screen have been there and elsewhere and might there be another cause to this?  Not sure how to investigate this further, but might check the relief valve seat for contamination. I think this could happen in a rather short time without obvious symptoms when running the engine. Just a thought due to my friends recent and unrelated story. 
 

Edit:  I think that both the thermostatic bypass and the pressure relief valve can play into this. An analogy might be taking off with a cold engine, before oil temperature is in the green. Oil pressure would be very high, over red, what gives in that situation?  

[A64Pilot]

46 minutes ago, takair said:

Oil pressure would be very high, over red, what gives in that situation?  

It’s extremely uncommon, being a warm weather guy I’ve never seen it, but often it’s the oil filter can itself that bursts. Or the oil cooler, there is always flow and pressure in the cooler

But you’re talking insane pressures, way past a peddled oil pressure gauge and really cold temps to get to those insane pressures. Tempest claims usually over 600 PSI

https://tempestplus.com/wp-content/uploads/2019/01/SB006-Remote-Oil-Filter.pdf

[alextstone]

1 hour ago, takair said:

Is it possible that there is another cause to this that is not related to the filter oring?  Maybe it was previously discussed, so apologies if I missed it. Is it possible that with colder oil the bypass did not work correctly and the filter was acting as a relief valve?  I had recently been talking to a friend who experienced this on an experimental that was full flow without a relief valve and the seal is what gave way. Could the stuff in the screen have been there and elsewhere and might there be another cause to this?  Not sure how to investigate this further, but might check the relief valve seat for contamination. I think this could happen in a rather short time without obvious symptoms when running the engine. Just a thought due to my friends recent and unrelated story. 
 

Edit:  I think that both the thermostatic bypass and the pressure relief valve can play into this. An analogy might be taking off with a cold engine, before oil temperature is in the green. Oil pressure would be very high, over red, what gives in that situation?  

That's an interesting bit of information...I'm not sure I understand how the filter could act as a pressure relief valve...are you saying that the oil pressure was excessively high, leading to the blowout of the seal? 

[takair]

9 minutes ago, alextstone said:

That's an interesting bit of information...I'm not sure I understand how the filter could act as a pressure relief valve...are you saying that the oil pressure was excessively high, leading to the blowout of the seal? 

Yes….I was just looking at your plots from page one and it appears your were near red line pressure and then there is a step change.  I wouldn’t be surprised if that is when the oring moved.  It clearly is not the kind of pressure relief you want.  This can happen on a traditional oil filter as well. I guess the question might be, is the reading accurate, where was the pressure measured in the plot….might not be the highest pressure.  Also, is the flow through the Challenger different, perhaps yields higher local pressure.  Basically, if the oil has no where to go at these high pressures, it can extrude the oring out of the seat…it is the weak link.  There are examples doing a Google search, airplanes, cars, etc.
 

Do you have plots of your oil pressure with a traditional filter?  Might be worth comparison.  

[Fly Boomer]

1 hour ago, A64Pilot said:

It’s extremely uncommon, being a warm weather guy I’ve never seen it, but often it’s the oil filter can itself that bursts. Or the oil cooler, there is always flow and pressure in the cooler

With cold oil, you can get a variety of outcomes:

MODERATE:  https://drive.google.com/file/d/1OoTGo5sChJvKscLhnh-7XKtxVw_Zsjnr/view?usp=sharing

SEVERE:  https://drive.google.com/file/d/1SuZQ5TxYylLkuTfc7JiD_qqkvR2iv7VI/view?usp=sharing

[EricJ]

1 hour ago, Fly Boomer said:

With cold oil, you can get a variety of outcomes:

MODERATE:  https://drive.google.com/file/d/1OoTGo5sChJvKscLhnh-7XKtxVw_Zsjnr/view?usp=sharing

SEVERE:  https://drive.google.com/file/d/1SuZQ5TxYylLkuTfc7JiD_qqkvR2iv7VI/view?usp=sharing

Lycomings send the oil straight from the pump through the cooler prior to the pressure regulator, so the cooler gets unregulated pressure.   This is one reason why cooler inspection is important, especially if you get over-pressure events.    Mine goes over redline pressure occassionally and my JPI and AV-17 make sure I know about it, so it can definitely happen.