Lycoming Connecting Rod Bushing AD 2024-21-02

[DCarlton]

Yeah this whole thing is a can of worms.  The fact that these bushings are manufactured and installed by Lycoming doesn't give me much confidence that the newer bushings are any better without more details.  Could be a lot of money spent for nothing.  Unless the suspect sub-populations of bushings have different defects, I can't understand why the second AD doesn't supersede the first one.  This must be maddening for the engine overhaul shops that try to do good work.  

[MikeOH]

I had never even heard of the 2017 AD before this came out.  I wonder how many engines have actually been torn open and subject to the inspection using the "Special Tool"?  Has anyone seen one 'in the wild'?  Are they even available, and at what cost?  As I mentioned before, and Mike Busch outlined in his letter, the potential for MIF performing this 'inspection' is likely far worse than the 'cure'.

The whole thing (both ADs) smack of CYA on the part of both Lycoming and the FAA

I'll speculate that no one was following the 2017 AD and another failure occurred and the FAA came up with this 2024 'monitor the oil filter/screens' AD...which is a lot like an AMOC that Busch suggested!

[Echo]

52 minutes ago, MikeOH said:

I knew I smelled a rat in this whole debacle; after reading the documents that @PT20J posted I have confirmed that my sense of smell is intact.

Wow. What a quagmire.  Look forward to FAA reply to AOPA letter.  The "cure" does appear to be worse than the "disease"...

[PT20J]

11 minutes ago, Echo said:

Wow. What a quagmire.  Look forward to FAA reply to AOPA letter.  The "cure" does appear to be worse than the "disease"...

That letter is 7 years old . 

[Echo]

51 minutes ago, PT20J said:

That letter is 7 years old . 

Wow.  Face palm.  No response from FAA until a new broadened AD?

[MikeOH]

21 minutes ago, Echo said:

Wow.  Face palm.  No response from FAA until a new broadened AD?

Yeah, this new AD IS the FAA's response to Mike's letter...7 years sounds about right for the FAA

[A64Pilot]

I’m failing to understand the Angst here? I agree I wouldn’t want a defective part in my engine, but

If I understand it and I’m not saying that I’m an expert because full disclose I’m going off only what I read here, but this AD isn’t requiring anything to be done that shouldn’t already be done anyway? IE inspecting the oil filter and suction screen?

It doesn’t even require it to be done by a licensed mechanic. Heck it even tells you where to go because before this AD if I found bearing material I would immediately suspect the worst and remove the engine and split the case, it could be a large money saver.

How much less intrusive would you like it to be and how?

Ref the I don’t know if the new ones are any better or not, again I can’t be 100% certain, but using a tool to determine if the bearing has enough interference fit screams to me that either the rod bore is oversized or the bushing undersized and not a materials defect issue.

Now this thing could grow arms and legs like the crank AD did, but as it began in 2007 seemingly I think it’s unlikely to do so.

[MikeOH]

@A64Pilot

While I can't speak for others, my angst is over what I see as deliberate withholding of key information that started back in 2017 and the imposition of a rather intrusive AD (that I suspect many didn't comply with) that was promulgated without proper procedure (you need to read both ADs, AOPA's and Mike Busch's letter, as well as the SB describing the earlier inspection procedure).  Part of this withholding of information is the lack of real sharing as to parts that were affected; I'm not sure Lycoming knows the real time frame and possible loss of traceability.  And, they won't even at least admit that.  Hiding behind 'proprietary' is a crap way to do business when it's a safety issue, IMHO.  It reeks of their lawyers 'advice'; kind of like Detroit when they weigh the cost of the lawsuits against the cost of recall...screw the number of people put at risk.

[DCarlton]

1 hour ago, A64Pilot said:

I’m failing to understand the Angst here? I agree I wouldn’t want a defective part in my engine, but

If I understand it and I’m not saying that I’m an expert because full disclose I’m going off only what I read here, but this AD isn’t requiring anything to be done that shouldn’t already be done anyway? IE inspecting the oil filter and suction screen?

It doesn’t even require it to be done by a licensed mechanic. Heck it even tells you where to go because before this AD if I found bearing material I would immediately suspect the worst and remove the engine and split the case, it could be a large money saver.

How much less intrusive would you like it to be and how?

Ref the I don’t know if the new ones are any better or not, again I can’t be 100% certain, but using a tool to determine if the bearing has enough interference fit screams to me that either the rod bore is oversized or the bushing undersized and not a materials defect issue.

Now this thing could grow arms and legs like the crank AD did, but as it began in 2007 seemingly I think it’s unlikely to do so.

If you hypothetically find yourself non compliant with the 2017 AD, there can be signifiant angst, especially if your engine only has a couple of hundred hours and it's running fantastic with no signs of metal in the oil.  You may experience heightened angst if your annual is less than two months away.  And you might actually considering buying a book of matches to drop in the fuel tank, if you were planning a $14K bladder install at the next annual and now you're uncertain if you have a connecting rod bushing issue that may require engine tear down even though a later AD was published that allows monitoring the same issue by oil analysis.  Angst could easily morph into, this is just too f'ing hard, I give up.  

BTW, how do you cut your losses and quickly sell an airplane that's non AD compliant?  Sell it at half its value before the AD and hope a mechanic buys it?  Fuel tanks need addressing deduct $15K.  2017 AD needs addressing deduct $10K.  Due for annual, deduct $5K.  Price to sell quickly, deduct $20K.  Nah... no angst.  Thanks to the discussion on Mooneyspace, I haven't bought the matches just yet.  

[A64Pilot]

Me, I’d comply with the 2024 AD, which I’m already complying with if I understand it, and I’d hope everyone else is too, and Ignore the 2017 until or unless it rears it’s ugly head.

I don’t think it’s going to amount to much because if it was, especially since it’s been ongoing for what 7 years and pretty much none of us have heard about it the likelihood of a rash of failures is pretty remote (in my opinion). This AD sounds to me like a CYA for I guess the FAA, or maybe Lycoming, who knows which, perhaps both?

Truth is we are all just finding steel in the filter away from something much more expensive than this, and the gear worry me. We have ALL heard of cam / lifter failures, how many have heard of these bushings failing?

Does insurance cover a gear up if the actuator quits? I don’t honestly know but I think maybe they don’t cover material failure or it would cover a bad cam too? 

So as I see it we are all flirting with disaster as it is, you either deal with it whatever way you can, or you sell.

Not trying to be nasty, but Certified aviation has always been like this and no aircraft make that I know of is Immune. At least we don’t have a wing spar AD etc, but as the fleet continues to age we are likely to see more AD’s.

The C-210 I had a wing spar AD to deal with and honestly I suspect failing it would condemn the airframe as I don’t know what it would cost to fix it as opposed to the value of the aircraft, no idea.

But small end rod bushings ought to not be all that hard or expensive honestly, not compared to what it could be.

Edited November 3, 2024 by A64Pilot

[Pinecone]

28 minutes ago, A64Pilot said:

Does insurance cover a gear up if the actuator quits? I don’t honestly know but I think maybe they don’t cover material failure or it would cover a bad cam too? 

Insurance will not cover the actuator, but will cover the damage from the gear up.

They will not cover the cam and lifters failing, but will cover the damage related to the engine failure.

[DCarlton]

44 minutes ago, A64Pilot said:

Me, I’d comply with the 2024 AD, which I’m already complying with if I understand it, and I’d hope everyone else is too, and Ignore the 2017 until or unless it rears it’s ugly head.

I don’t think it’s going to amount to much because if it was, especially since it’s been ongoing for what 7 years and pretty much none of us have heard about it the likelihood of a rash of failures is pretty remote (in my opinion). This AD sounds to me like a CYA for I guess the FAA, or maybe Lycoming, who knows which, perhaps both?

Truth is we are all just finding steel in the filter away from something much more expensive than this, and the gear worry me. We have ALL heard of cam / lifter failures, how many have heard of these bushings failing?

Does insurance cover a gear up if the actuator quits? I don’t honestly know but I think maybe they don’t cover material failure or it would cover a bad cam too? 

So as I see it we are all flirting with disaster as it is, you either deal with it whatever way you can, or you sell.

Not trying to be nasty, but Certified aviation has always been like this and no aircraft make that I know of is Immune. At least we don’t have a wing spar AD etc, but as the fleet continues to age we are likely to see more AD’s.

The C-210 I had a wing spar AD to deal with and honestly I suspect failing it would condemn the airframe as I don’t know what it would cost to fix it as opposed to the value of the aircraft, no idea.

But small end rod bushings ought to not be all that hard or expensive honestly, not compared to what it could be.

I would handle it the way you suggest too if I could sign my own logbooks.  Hope to know more next week.  Yes certified aviation has always been like this but the nearer you get to the end, the less tolerant you are of unexpected issues that impact your ability to enjoy a few more years of flying.  In the beginning it's all part of the journey and the price of admission.  

[A64Pilot]

Just got through scanning the 2017 MSB.

As they have each engine identified by serial number, I think that means Lycoming factory overhauls. I can’t image they could possibly know about field overhauls as in which serial number may have gotten the suspect bushings.

Pure supposition, but it would be interesting to know how many of us are affected by this SB/AD. 

I would also hope that anyone that was if my supposition that’s its factory engines have been contacted by Lycoming years ago as surely they know where they went from Warranty registration if nothing else.. (another supposition) but either way it ought to be pretty easy to check serial number of engine against the AD before you go to bed and see if your affected, if you are by engine AD standards this isn’t a bad one. You can do one at a time and or install torque plates if you need to pull more than one.

Interesting that the FAA if memory serves uses $85 an hour labor, my local Jeep dealer is $185 an hour and they say they aren’t higher than anyone else.

[A64Pilot]

1 hour ago, Pinecone said:

Insurance will not cover the actuator, but will cover the damage from the gear up.

They will not cover the cam and lifters failing, but will cover the damage related to the engine failure.

Now that you say it that’s what I remember, but didn’t until you posted and jogged my memory

[DCarlton]

43 minutes ago, A64Pilot said:

Just got through scanning the 2017 MSB.

As they have each engine identified by serial number, I think that means Lycoming factory overhauls. I can’t image they could possibly know about field overhauls as in which serial number may have gotten the suspect bushings.

Pure supposition, but it would be interesting to know how many of us are affected by this SB/AD. 

I would also hope that anyone that was if my supposition that’s its factory engines have been contacted by Lycoming years ago as surely they know where they went from Warranty registration if nothing else.. (another supposition) but either way it ought to be pretty easy to check serial number of engine against the AD before you go to bed and see if your affected, if you are by engine AD standards this isn’t a bad one. You can do one at a time and or install torque plates if you need to pull more than one.

Interesting that the FAA if memory serves uses $85 an hour labor, my local Jeep dealer is $185 an hour and they say they aren’t higher than anyone else.

Dig a little deeper.  If I remember correctly Table 1 provides the serial number for the LYC factory engines.  Look at Table 2.  It provides the dates that the suspect bushings may have been shipped to outside shops.  

[Pinecone]

2 hours ago, A64Pilot said:

Interesting that the FAA if memory serves uses $85 an hour labor, my local Jeep dealer is $185 an hour and they say they aren’t higher than anyone else.

Yes they do.  And for the new AD the expect that the rod bushing inspection is 1 hour.

Hmmm, maybe if the rod is out of the engine.

[A64Pilot]

9 hours ago, Pinecone said:

Yes they do.  And for the new AD the expect that the rod bushing inspection is 1 hour.

Hmmm, maybe if the rod is out of the engine.

I think the new AD the pilot can accomplish assuming of course they do their own oil change, if they have someone else do it, then there shouldn’t be any additional charge, because any licensed mechanic should be inspecting the filter anyway, and saying you complied with the AD is just another line in the oil change entry.

However I wouldn’t  be surprised if some do add some additional charge, it’s getting tough to make a living, just like where we eat Breakfast every Sun morning the coffee costs $2.50 now as they try to sneak in charges to stay afloat.

If in fact and I think it is, but if an Automobile dealer gets $100 an hour more labor than an Aviation shop, no wonder why there is a shortage of good aircraft mechanics.

Anyway just an opinion, but if you fall into the possible for the 2017 AD and are worried I’d do the AD.

But as the 2024 AD does not require disassembly and should provide the same level of safety with just filter inspections it does make one wonder if the tear down is required.

I couldn’t post last night, kept getting this message, was I the only one?

 

Edited November 4, 2024 by A64Pilot

[DCarlton]

https://www.globalair.com/articles/faa-issues-ad-affecting-16000-lycoming-engines?id=8168

I'm still ferreting around trying to find a hint of anything that suggests whether the bushings supplied between Jan 2009 and Nov 2015 (requires oil filter inspection) are any different than the ones supplied from Nov 2015 to Nov 2016 (requires visual inspection and a press fit test).  So far nothing...  

[N201MKTurbo]

If you read the procedure for installing the old style bushings, it looks like a better deal if done right. You drive the bushing in, then burnish it, which, I believe will cause it to expand locking it in place. Then reaming it out to the final size. This probably produces a superior fit, but it involves a bit of craft work and experience. If this procedure was done wrong, things could go to hell. 
 

Perhaps, it wasn’t bad parts, but all the craftsmen retired and the new kids just didn’t know how to do it right.

The new bushing just presses in with no other processes.

[DCarlton]

1 hour ago, N201MKTurbo said:

If you read the procedure for installing the old style bushings, it looks like a better deal if done right. You drive the bushing in, then burnish it, which, I believe will cause it to expand locking it in place. Then reaming it out to the final size. This probably produces a superior fit, but it involves a bit of craft work and experience. If this procedure was done wrong, things could go to hell. 
 

Perhaps, it wasn’t bad parts, but all the craftsmen retired and the new kids just didn’t know how to do it right.

The new bushing just presses in with no other processes.

I have no practical experience building an aircraft engine but I’ve had similar thoughts.  An experienced guy that meticulously hand builds an engine in a reputable overhaul shop might do a consistently better job than someone on a production line putting round pegs in round holes as fast as possible.  It would help to have more information on the root cause of failure.  

[MB65E]

That’s my guess with the AD, as it was a poor install process from Lycoming. Aircraft Engine Specialties has been doing it right for a long time. 
I think many will find that it’s just more words on your LBE for the oil change. 
-Matt 

[PT20J]

MSB 632B referenced in the first (2017) AD describes the bushings as non-conforming and implies that some bushings were of incorrect diameter.

[MikeOH]

10 minutes ago, PT20J said:

MSB 632B referenced in the first (2017) AD describes the bushings as non-conforming and implies that some bushings were of incorrect diameter.

That's my take, as well.  The "special tool" is designed to apply a known force to the bushing to try and push it out of the connecting rod.  If it moves then it's deemed 'bad'.  If it does not move, then it's 'good'.  That pretty strongly implies poor manufacturing control over the outside diameter of the bushing.

[Echo]

On 11/4/2024 at 6:03 AM, A64Pilot said:

I think the new AD the pilot can accomplish assuming of course they do their own oil change, if they have someone else do it, then there shouldn’t be any additional charge, because any licensed mechanic should be inspecting the filter anyway, and saying you complied with the AD is just another line in the oil change entry.

However I wouldn’t  be surprised if some do add some additional charge, it’s getting tough to make a living, just like where we eat Breakfast every Sun morning the coffee costs $2.50 now as they try to sneak in charges to stay afloat.

If in fact and I think it is, but if an Automobile dealer gets $100 an hour more labor than an Aviation shop, no wonder why there is a shortage of good aircraft mechanics.

Anyway just an opinion, but if you fall into the possible for the 2017 AD and are worried I’d do the AD.

But as the 2024 AD does not require disassembly and should provide the same level of safety with just filter inspections it does make one wonder if the tear down is required.

I couldn’t post last night, kept getting this message, was I the only one?

 

No, not the only one.

[DCarlton]

10 hours ago, PT20J said:

MSB 632B referenced in the first (2017) AD describes the bushings as non-conforming and implies that some bushings were of incorrect diameter.

They had to describe the "defect" somehow.  Their words could mean anything without more details (I've written DOD failure analysis reports choosing every word carefully).  They're about to gather a lot of data with 16,000 recurring oil filter inspections.  Hopefully they won't need to expand the compliance requirements described in the first AD to cover all 16,000 engines.  That would be a huge blow to GA.  I certainly won't get an answer if Mike Busch didn't but I'm going to ask whether there is any difference in first smaller population of bushings vs the expanded population.  I'll bet every engine shop in the country is asking the same question.  They deserve a detailed answer.