Lycoming issued a Mandatory Service Bulletin on Monday that requires all owners and operators of its engines to check them for connecting rods that contain bushings that do not meet Lycoming Engine’s specifications, and if the bushings are found, to take follow-up corrective action. This inspection must be completed within the next 10 hours of engine operation. The SB contains a “Warning” to owners: “You must complete the ‘Required Action’ in this Service Bulletin. If you do not complete the ‘Required Action’ in this Service Bulletin, and the connecting rod bushing moves out of place, the connecting rod can fail and cause un-commanded structural engine failure.”

The first step in the SB requires operators to check their engine serial numbers to identify affected engines. Then, if the engine is affected, the Lycoming parts source must be contacted to review all the engine paperwork to determine whether your engine could have one or more of the suspect connecting rod bushings or connecting rod assemblies. If the suspect parts are found, owners must remove the engine, complete the inspection, and reinstall the engine. That process could take 12 hours for a four-cylinder engine and up to 20 hours for an eight-cylinder engine. The work may be covered under warranty, Lycoming said.

http://www.lycoming.com/sites/default/files/SB632%20Connecting%20Rod%20Identification%20and%20Removal_0.pdf

...and cause un-commanded structural engine failure.

I personally only go for the commanded structural engine failure.

Joking aside, sucks for those affected.

--Tony

Just emailed the shop that pressed my rod bushings in this winter... holding breath.

Table 2 is what would affect me, the new parts purchased recently.

"LW-13923 Connecting Rod Bushing shipped between 18 November 2015 and 15 November 2016"

Ugh. Thanks for posting, Greg.

You gotta love aviation.

The manufacturer installs defective parts that could kill you and they 'may' cover it under warranty.

Even if they did what about the downtime and associated labor, which is going to be significant.

Thanks for the info ! Just checked and my serial number isn't on the list. Now that I'm finally getting it ready to fly after a year and a half restoring it, the last thing I need is an SB or AD to stop my progress.

I've read it twice so far. Looks like I may have dodged a bullet

What a PITA....

If your engine was in pieces for a major overhaul right now, you'd be pretty happy about the timing.

Are "mandatory service bulletins" truly mandatory for non-commercial GA operators? I seem to recall Mike Busch (and others at EAA and AOPA) categorically stating that they are NOT mandatory until the FAA issues an AD. It may be a really good idea to comply with the SB – especially one like this that could result in engine failure – but I didn't think it was truly "mandatory" for most of us.

Never been quite so happy to have purchased my Champion 7ECA with the lowly Continental O-200 engine... Whew!

Battson wrote:What a PITA....

If your engine was in pieces for a major overhaul right now, you'd be pretty happy about the timing.

Ummm yeah, I guess it's lucky timing. I'm going to assemble the bottom end without rods starting Friday. Already been down this road once before helping install rods after the case was sealed on a 470. Need to train some tiny-handed children.

JP256 wrote:Are "mandatory service bulletins" truly mandatory for non-commercial GA operators? I seem to recall Mike Busch (and others at EAA and AOPA) categorically stating that they are NOT mandatory until the FAA issues an AD. It may be a really good idea to comply with the SB – especially one like this that could result in engine failure – but I didn't think it was truly "mandatory" for most of us.

Never been quite so happy to have purchased my Champion 7ECA with the lowly Continental O-200 engine... Whew!

Not mandatory for part 91 guys. May affect 135 operators though.

JP256 wrote:Are "mandatory service bulletins" truly mandatory for non-commercial GA operators? I seem to recall Mike Busch (and others at EAA and AOPA) categorically stating that they are NOT mandatory until the FAA issues an AD. It may be a really good idea to comply with the SB – especially one like this that could result in engine failure – but I didn't think it was truly "mandatory" for most of us.

Never been quite so happy to have purchased my Champion 7ECA with the lowly Continental O-200 engine... Whew!

No they are mandatory until an AD comes out. But if it's a big concern, an AD will come out shortly. For this type of thing I'm expecting an AD soon.

Sent from my SM-G870W using Tapatalk

JP256 wrote:Are "mandatory service bulletins" truly mandatory for non-commercial GA operators? I seem to recall Mike Busch (and others at EAA and AOPA) categorically stating that they are NOT mandatory until the FAA issues an AD. It may be a really good idea to comply with the SB – especially one like this that could result in engine failure – but I didn't think it was truly "mandatory" for most of us.

Never been quite so happy to have purchased my Champion 7ECA with the lowly Continental O-200 engine... Whew!

No, even for the 135 operators I have worked for. For part 91 it's not truly "mandatory" until the FAA issues an AD, which often happens with "mandatory" SB's so if your SN is affected by this SB and you decide not to comply, expect it to become an AD and truly mandatory in the near future.

As far as 135 operators, it's still not technically "mandatory" although their approved operation manual may state that they will comply with mandatory SB's in which case they are breaching their stated procedures by not complying with the agreement they made with the FAA which as you can understand can lead to bad things.

As a big believer in the Waddington effect (Hal Waddington RAF WWII researcher that proved that reliability centered maint reduced aircraft down time from maintenance induced failures), if I had an affected engine that was running well for a few years and a few hundred hrs or so I think I would leave it be and calling the likely hood of the affected component failure this late in the game about the same as a maintenance induced failure from tearing down and putting it all back together again. Just me.

Interesting article by Mike Bush concerning this.

https://blog.aopa.org/aopa/2017/08/25/the-shameful-lycoming-rod-bushing-ad-affair/?utm_source=ePilot&utm_medium=Content&utm_content=blog&utm_campaign=170831epilot.

In discussing this situation with companies like Rick Romans and Aircraft Specialties Services and Zephyr Aircraft Engines who are in the business of re-bushing Lycoming connecting rods in the field, it appears that the problem with these loose Lycoming connecting rod bushings has been well-known by industry insiders for more than a year. Several of those firms told me that they stopped installing Lycoming-supplied rod bushings many months ago in favor of PMA-equivalent bushings from Superior Air Parts that fit properly.