Lycoming piston pin AD

Doc Holliday said:
What do you propose they should use?
Click to expand...
Their estimate doesn’t include the extra work that usually is needed especially the well since we are in here.

pulling cylinders will find numerous pitted cams I bet.

Maybe just leave the cost estimates out of report.
 
bonefishpete said:
Maybe just leave the cost estimates out of report.
Click to expand...
They can't as the cost estimates are part of the required NPRM process. However, keep in mind those costs only apply to the labor and part cost specific to the AD. There are a number of guidance docs that explain how they calculate those costs. Regardless, you also have the ability to make comments on those costs during the AD NPRM process but prior to it reaches the final rule like this one.
 
bonefishpete said:
Their estimate doesn’t include the extra work that usually is needed especially the well since we are in here.

pulling cylinders will find numerous pitted cams I bet.

Maybe just leave the cost estimates out of report.
Click to expand...
What Lycoming engine do you have with numerous cams?
 
Clip4 said:
What Lycoming engine do you have with numerous cams?
Click to expand...
I said I bet. Don’t you hear pre buy guys say they want a cylinder pulled to inspect cams for corrosion?

Cams don’t go bad from corrosion in Lycoming engines?
 
Bell206 said:
They can't as the cost estimates are part of the required NPRM process. However, keep in mind those costs only apply to the labor and part cost specific to the AD. There are a number of guidance docs that explain how they calculate those costs. Regardless, you also have the ability to make comments on those costs during the AD NPRM process but prior to it reaches the final rule like this one.
Click to expand...
I understand but how many jobs come in at or under AD estimated costs?

What shop rate they using?
 
The whole Lycoming camshaft pitting thing is overblown. How many engine failures are attributed to it? How many owners experience performance degradation due to pitted cams wearing out?

If you don't want your engine corroding internally, stop doing the things that corrode it. Don't ground-run it and then put it away. Fly it. Don't make 10-minute flights. These engines are not car engines; their clearances are larger due to wide temperature swings. They have no PCV system to clear bad stuff out of the crankcase. Water and other corrosive stuff gets past the rings when the engine isn't at operating temperature, and if it isn't flown, that stuff is not boiled out and sent out of the breather. It stays in the engine and goes to work eating it.
 
bonefishpete said:
I said I bet. Don’t you hear pre buy guys say they want a cylinder pulled to inspect cams for corrosion?

Cams don’t go bad from corrosion in Lycoming engines?
Click to expand...
The Lycoming engine has one camshaft (cam) and pulling one cylinder will not allow for a complete inspection of the camshaft because the engine crankcase features internal structural bearing saddles and webs that separate the case into distinct compartments,
 
bonefishpete said:
I understand but how many jobs come in at or under AD estimated costs? What shop rate they using?
Click to expand...
None. But if you understand the process you’ll know it’s only an administrative cost calculation per the requirements of the APA Act. Its not a job quote or estimate that also includes shop overhead, profit, etc. and is unique to each shop or service provider. So no comparison. Below is one explanation of how the AD labor rate is calculated from a Boeing 787 AD NPRM as someone had questioned the rate during the comment phase of the NPRM.

1788025369885.png
 
sure, we stipulate the mechanics of corrosion, and chastising people for underutilization is after all par for the course/factory default POA reactionary brain on a saturday morning. But these engines when flown recreationally, are nevertheless operated with the very infrequency that favors a PCV powerplant over an open case setup.

We had a fellow POA contributor die in 2021 to a corroded-to-h-e-double-hockey-sticks Lycoming (hope I don't get a bad word warning from the deity-believing mods for that one). In fairness, we've had others go down on Contis on account of internally degraded components (@GMascelli ) as well; before people think I have a vendetta against lycos just because I had mine tried to mort me 60 unsuspecting hours after I had crossed the deepest trench in the Atlantic ocean behind it. :oops: username checks. Point being, it's not exactly zero either.

I still contend it is the powerplant capture what's killing the affordability (thence viability, yes even in EAB) in this hobby, very much pardon the pun (RIP @GaryV). As a recreationalist I can't offer these sellers a price that can pencil out powerplant replacement, even after I eat the price risk of unobtanium airframe issues (just recently walked away from a 210A bid on account of the saddles procurement situation in 2026). As a flight school peddler to airline dreamers maybe one could cost-shift it I suppose, but that's not a use case that furthers the avocation imo.

The clone engine market has been the biggest disappointment to me, makes the LSA affordability pitch of the early 2000s seem realistic by comparison.
 
Clip4 said:
The Lycoming engine has one camshaft (cam) and pulling one cylinder will not allow for a complete inspection of the camshaft because the engine crankcase features internal structural bearing saddles and webs that separate the case into distinct compartments,
Click to expand...
If one end of that camshaft is corroded, the other will be, too. One can check for internal corrosion just by taking off a mag and looking at its drive coupling or gear, and the gears visible in the accessory case. They're all steel and they all corrode if moisture is present in that engine.
 
bonefishpete said:
Their estimate doesn’t include the extra work that usually is needed especially the well since we are in here.

pulling cylinders will find numerous pitted cams I bet.

Maybe just leave the cost estimates out of report.
Click to expand...
What does finding unrelated issues have to do with the piston pin? It’s impossible to estimate what else will be found.
 
bonefishpete said:
Usual low estimate on money required.
Click to expand...
Has anyone here seen an hourly shop rate of $85 in the last 5 years?

The AD does not affect me, however, I'd like to know if my camshaft was pitted.
 
So if my engine was rebuilt with non Lycoming cylinder kits, I exempt from this, or in another case, rebuilt 12 yeas ago?
 
Ventucky Red said:
So if my engine was rebuilt with non Lycoming cylinder kits, I exempt from this, or in another case, rebuilt 12 yeas ago?
Click to expand...
Probably...based on the date you mention and no subsequent engine work. But if your engine is listed in AD applicability statement or Table 2 or 3 for the stated MSB, you'll still need an N/A sign off for the AD in the book.
 
Last edited:
bonefishpete said:
Their estimate doesn’t include the extra work that usually is needed especially the well since we are in here.

pulling cylinders will find numerous pitted cams I bet.

Maybe just leave the cost estimates out of report.
Click to expand...
what Does that have to do with the AD? The AD didn’t pit the cam. Not having the AD doesn’t make the cam not pitted. The mechanic could have a heart attack when pulling the cylinder, do they need to add his healthcare to the estimate?
 
Salty said:
what Does that have to do with the AD? The AD didn’t pit the cam. Not having the AD doesn’t make the cam not pitted. The mechanic could have a heart attack when pulling the cylinder, do they need to add his healthcare to the estimate?
Click to expand...
Collateral damage I think is what is being referenced. For example, know of a small Lyc that stuck a valve. Cylinder needed to come off. Cam shot, overhaul time. It happens.
 
Steamflyer said:
Collateral damage I think is what is being referenced. For example, know of a small Lyc that stuck a valve. Cylinder needed to come off. Cam shot, overhaul time. It happens.
Click to expand...
You can put the cylinder back on and be right back where you were.
 
bonefishpete said:
Will the A&P sign off the repair? What has been seen can not be unseen.
Click to expand...
Depends. Changing a piston pin hardly requires looking deep inside the engine especially if the owner only wants the AD complied with. Second, when you sign off the AD under Part 43.9 you're only taking responsibility for the work performed and not what you saw. Regardless, it still falls to the owner what is accomplished and what is not. But for context, if I noted a flight safety issue in the middle of a mx task that would be covered up once completed, which the owner chose not to address, I would politely stop work, sign off what I had performed, and walk away.
 
If I'm understanding the proposed AD correctly...

This only hits engines if a piston pin P/N LW-13445 manufactured between January 7, 2021 to December 15, 2025? So if an engine's last overhaul was prior to that 2021 manufacture date and the piston pins haven't been touched since this would not apply, correct?
 
cowman said:
If I'm understanding the proposed AD correctly...

This only hits engines if a piston pin P/N LW-13445 manufactured between January 7, 2021 to December 15, 2025? So if an engine's last overhaul was prior to that 2021 manufacture date and the piston pins haven't been touched since this would not apply, correct?
Click to expand...
correct. Most folks are not affected this time.
 
cowman said:
If I'm understanding the proposed AD correctly... This only hits engines if a piston pin P/N LW-13445 manufactured between January 7, 2021 to December 15, 2025? So if an engine's last overhaul was prior to that 2021 manufacture date and the piston pins haven't been touched since this would not apply, correct?
Click to expand...
Technically, its applicable to the engine models listed on the AD with serial numbers listed in the MSB and any installed piston pin LW13445 with the stated dates. So if your engine is outside those two defining requirements its not applicable. And to add, this not a proposed AD but a final rule and goes into effect on Sept 14, 2026.
 
Salty said:
Then it needed to be dealt with before the AD
Click to expand...
Wasn't known until the AD forced the cylinder pull. One of those weird things - if it's there but you haven't seen metal in the oil, you don't know. Once you see it, you can't unsee it. And since this is Lycoming, I don't think there is guidance for how much pitting or spalling is too much - Continental does have information as to such in the M0 manual.
 
You must log in or register to reply here.
Back
Top