DCarlton

Take a look at the one used on the Pipers. With the right hardware it can work just fine.

Would really like to hear Lycomings thoughts on why the 2017 and 2024 ADs have different compliance requirements for the same P/N, particularly IF the defect is the same for the two populations of bushings. {Note: I was told by a reputable builder they've seen bushing move as well but so far not enough to make metal; I was also told some of the defective bushings were identified and rejected because they were too easy to hand press into the rod; I have a bit more gut confidence since my bushings were hand pressed into the rod.}

Your 5th para is exactly what I was trying to suggest. And when I said oil inspections I was being too brief and not specific enough; best to read the SB (I'll be looking at whatever I can for particles and probably sending the oil off for analysis too). Regarding your 6th para; I asked for an estimate from a reputable trusted builder. In CA it's $4500 to remove four cylinders and perform the press out test. Compare that to the FAA estimates. Sorry for begin too brief but Mooneyspace kept bombing; said too many users were logged in or something like that. Again, I'm no expert mechanic; just a retired DOD engineer / owner with time enough to investigate this issue myself and read the documents.

And if you don't have the Lyc ship dates (or they've been disposed of after five years), you've got a practical choice to make. Recurring oil inspections for metallic solids or a bushing press out test for ~ $4500.

Nice that your DG Adapter is easy to access. Those test ports can be handy. Mine is tucked away behind the left footwell carpeted panel against the firewall.

The FAA just responded to my inquiry. I was told I'd need to fill out a Freedom Of Information Act Request that would be reviewed to determine if any information can be disclosed due to the proprietary nature of the issue. I responded by asking a few more general questions regarding the two populations of bushings. Update. According to the FAA POC, the failure mode for the two populations of bushings addressed by the two ADs appears similar.

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.

I'm on my third cover. I had a boat upholstery / canvas / sail shop make my last one out of Sunbrella fabric using one of the previous covers as a template. It's a little heavier and bulkier but it's lasted twice as long as the other covers. I don't take it with me when I fly. If I did, I'd probably buy another cover like the ones mentioned above.

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.

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...

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.

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.

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.

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.

If I close my baggage door, I lock it. And every time I board the airplane, I tug on the handle.

I did everything but the headliner in my plane years ago. I used the pre cut insulation kit. Now wish I had done the headliner; it's sagging in a few area. If you could find some compliance self stick material, I can't imagine it being that difficult. If you've gotta spray glue, seems like it could be messy.

Makes complete sense from a process perspective. From a practical perspective though, it appears that they both address the exact same part with the exact same problem; but based on more data, they've relaxed the compliance requirement. I'm guessing it would be hard for the FAA to now say, the first AD based on limited data was overkill.

Looks like a nice airplane at a fair price with a lot of the hard work already done. Good luck.

If that's for a 430, I'll take it. Those are getting hard to find and I've had at least one corrupted during database updates.

I'm planning to reread the two ADs again today along with the SBs, but I'm stumped from a process standpoint as to how to rectify the compliance requirement differences between the 2024 and 2017 ADs. I believe the 2017 AD requires bushing visual inspection and/or replacement and the 2024 AD (based on more data) only requires oil particulate inspection. I haven't seen where the 2024 AD supersedes the 2017 AD. Even if the FAA assumes, the 2017 AD has been complied with by now, most certainly there have been escapes.

Yep. Everyone with an engine overhauled in late 2015 to late 2016ish needs to take a close look at their paper trail. However not clear now why compliance requirements are different on the two ADs.

That’s not the way I read the 2017 AD. Although I would prefer your interpretation.

Update. I'm no expert; just trying to connect the dots. It looks like AD 2024-21-02 is an expansion of AD 2017-16-11 which points to LYC SB 632B for action. SB 632B provides Table 1 with serial number of affected engines. For overhauled engines, Table 2 provides shipment dates for suspect bushings. IAW para 1.B, I've consulted with my overhaul shop to determine if I may have suspect bushings. Again. I'm not a mechanic or an expert. Just an owner trying to get ahead of a potentially painful problem. My engine has less than 200 hours.

Just checked my engine logs. My engine overhaul was signed off in July 2016. The LW-13923 bushing were replaced during overhaul. The FAA has a concern about bushings shipped up until 11/17/2015. So now I have to wonder whether the overhaul shop used up the 2015 bushings they had on the shelf before they started my overhaul. I may have squeaked by..... or not. Gonna email the shop and see if they keep those sort of records (when parts were received). I'm planning to start checking for particulates and doing oil analyses anyway just to feel "better".

Great questions but I'd still like to know why the bushing were "bad". Wrong alloy? Not machined to correct tolerances? Why wasn't this caught during QA? How did they confidently isolate the production lots in question? What steps have been taken to make sure the new bushing don't have any QA issues? To manage this issue the FAA has to know the answers to these types of questions, otherwise, they're shooting from the hip. I wouldn't want to crack open a good engine at significant cost without more details. Guessing there's a detailed failure analysis report somewhere. I asked for it; no idea if I'll see a response.