Incident Sonex N1611S

[WaiexN143NM]

Hi peter,
Lol, keep the plane, re engine it, keep the wife, pass on the t-shirt.

Michael.

[daleandee]

After 52 years of marriage I think I will keep her and have an X Sones.

Hi Peter,

My remark was tongue in cheek to say the least. I've only had mine for 30 years ... but she allows me to fly. 52 years is quite impressive so I agree you'd do very well to continue with the one you have.

I wouldn't trade mine for an airplane that let me down either ... but the Cleanex is another matter entirely! OK not really!

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
Signature Finish 2200 Paint Job
171.2 hours / Status - Flying
Member # 109 - Florida Sonex Association
Latest video: https://www.youtube.com/watch?v=1VP7UYEqQ-g

[eppre]

Hey guys,

The reason 1611S came out of the sky was simple. I found the answer in about three minutes. I took the top cowl off and one of of the right rear cylinder rod bolt and part of the rod end that goes around the crank was lying beside a two inch hole in the top of the case. The rest of the end of the rod was sticking out another hole in the top of the case. Case closed.

Dose anyone out there want to by a lovely flying Sonex. Added up the cost of parts from Sonex and the bill comes to $2500 - #3000. Great flying plane. Make me an offer.

Hate to walk away but Just can't afford to put more into it. I already have over $37000.

Pete

[eppre]

By the way guys I have a great wife and she says I can keep the plane but I know she would be thinking about it every time I went out to fly. Just not fare to her.

[Direct C51]

I would say this is far from case closed. What caused the rod to fail? Can you see where the failure point originated? A crack or ding, or in some way a stress riser? This is not a common occurance.

[lgsievila]

Without seeing the damage or having a complete failure mode analysis to review it is very difficult to determine the root cause of the failure. From what has been reported so far I think it is unlikely that the connecting rod itself failed but rather the end cap failed when one of the bolts holding the end cap failed. Failure of an end cap bolt can be caused by over-torqueing during assembly of the engine or just simply a flawed bolt.
One bolt will hold for a short time but then the failure will be catastrophic without any warning making new inspection holes in the crankcase as mentioned above.

Ask me how I know-I had an Lycoming IO 360 in a Piper Arrow that did the same thing.

[gammaxy]

Great job on the landing!

Thanks for the additional information, I believe it's very valuable for those of us who are also attempting to safely build, maintain, and operate our engines. I'm curious if the high oil temperature, two high CHTs, and loose head nut you've mentioned previously were somehow related to the failure.

[XenosN42]

Hey guys,

The reason 1611S came out of the sky was simple. I found the answer in about three minutes. I took the top cowl off and one of of the right rear cylinder rod bolt and part of the rod end that goes around the crank was lying beside a two inch hole in the top of the case. The rest of the end of the rod was sticking out another hole in the top of the case. Case closed.

Dose anyone out there want to by a lovely flying Sonex. Added up the cost of parts from Sonex and the bill comes to $2500 - #3000. Great flying plane. Make me an offer.

Hate to walk away but Just can't afford to put more into it. I already have over $37000.

Pete

Do you have any pictures you can share?

Michael
OneX N169XE
(and formally Xenos N42XE)

[eppre]

Engine Damage

On Lake

I am sure that the previous troubles were not the source of the current situation. The loose head bolt was due to the failure of the Nika cylinders that I originally used.

That was over 68 hours ago. The plane was flying great, no heat problems, full of oil, cool day, etc. I am sure the tuque was correct and double checked. It could have been a weak rod, I simply don't know. I have worked of enough engines to know that these things happen. I was a Chevrolet mechanic for years and have built engines. I don't blame anyone. Things just happen. I was fortunate to have a ice covered lake close by so all ended well.

[lgsievila]

Hi Pete,
I didn't mean to suggest that you made a mistake when you built the engine-I was just pointing out 2 reasons that I knew of for an end cap to fail. After seeing the picture and what looks like the part of the connecting rod is missing it looks pretty much like the Lycoming IO-360 I had that came apart in flight. Can you see any more of the rest of the connecting rod and does the other side look to be in tact? If it does look ok I think it is possible that side bolt failed and rod would fail like the picture shows because the other end cap bolt was still holding. We found part of a end cap bolt in the bottom of the case when the engine was disassembled but were not able to determine what caused the failure. That engine had about 200 hours SMOH when it failed.

Great job getting the plane down safely!