Some Rusty strut pictures

[jdoran]

Re: Some Rusty strut pictures

Dave,

Thanks on behalf of some of us that aren't very experienced in finding or seeing stuff like that.

I am a low time owner of a Tcraft, and when someone says corrosion exists inside struts-near the bottom, I have a hard time visualizing that.

The pictures removed the mystery, and furthermore-they prove not to let you guard down even if you have sealed struts.

Now, if we can see some photos of the failed attaching bracket/weldment that cause the Wiley accident, we will know the full scope of what to look for.

Remember, some of us are new at this and need extra help understanding.

[Forrest Barber]

Re: Some Rusty strut pictures

thank you for the reminder that we have new guys, I have struts cut apart here in Alliance. Will photo & post. Somehow the rusty attach brackett got posted on another thread.

[Len Petterson]

Re: Some Rusty strut pictures

Looking at the inside corrosion of the struts and bracket carytrough welded into the strut and the corrosion in the area surunding the weld.
How much of the material are ACTUALY missing, corroded away?
If the part was sandblased clean we could see how deep the piting is.
Would this strut be close to failing?
How much material can we afford to loose = what is minimum "average" thinkness allowable?
Or does it look worst when it is?
It will always be corrosion in steel, unless you can/are maintaning the corrosing protection one way or another.
Is a pitting trough in "one" place reason to scrap a strut? For example: a pinhole occures
If proven to be in one place only.
I have repair in the upper part of one strut, we checked them last year and they sounds very solid.

Len

[Buell Powell]

Re: Some Rusty strut pictures

Len,
I think the only way to determine if a strut is under the limits of allowable stress and about to fail is by a stress or pull test. What has been proven is that if neglected the inside of a stut will corrode and that some struts have corroded well past the point that should have been detected by even a visulal inspection if they were on a flying airplane. I think it would be very useful information to do tests to find out how bad a strut has to be before it is dangerous. We know that Mr. Taylor improved the struts when he developed the Taylorcraft strut. In looking at Taylorcraft strut fitting I also noticed that the strut fittiing looks like it is also a better design. I believe he also notced the stress on the Cub struts(a lot of old J-3 struts are bowed) and improved it so there is less stress on the lower end. I am not an engineer but this is how it looks to me.

[Buell Powell]

Re: Some Rusty strut pictures

It would be interesting that if someone who has some badly corroded struts could do a stress test and then cut them open to see how much wall thickness is lost and over how much area.

[Forrest Barber]

Re: Some Rusty strut pictures

This was done here many years ago at the Feris factory I have had sections of struts on display at the many Fly-Ins here at Alliance. IMHO the area along the "neutral axis" (center of the strut) seems to carry the loads. All this is academic since CAR 18 and the follow ups under 43 all specify the extent of deterioration that can be allowed. Any good mechanic should be knowledable enough to question rust, corrosion, pits, poor welds, etc..... IF not then he should consult a person who knows. Yes , many are not a round anymore I ahve found everybody I ahve talked to at the NTSB and FAA are thirsty for knowledge.
How to share and how to collect , store and disseminate THAT is the problem. On another thread I went over the present method , IT IS STILL up to the OWNER to get the information. If you own an OLD aircraft treat it as such. bye

[Buell Powell]

Re: Some Rusty strut pictures

Forrest,
What I am thinking is that when you apply pressure so something shaped like a strut and the ends are rigged it will cause it to bow in the center. If it can piviot on the end then there is less pressure to cause it to bend. In comparing the fuselage strut fitting of a J-3 Cub to a Taylorcraft it looks like the Taylorcraft allows more freedom for it to rotate and less pressure. Just something I was wondering about does this seem reasonable?

[Forrest Barber]

Re: Some Rusty strut pictures

Yes, C.G. thought of that, if you remember the early ships had the horizonal stab bolts running fore & aft , after he left they went to the vertical bolt, probably for ease of maintenance........