Elevator torque tube failure.

[radfordc]

I received a call from the guy who bought my Sonex. His A&P was doing some work on the plane and happened to discover that the elevator torque tube was rusted completely through in several spots! I just about got sick from the thought of what this could have meant if it had not been found in time. This is a plane that has been inspected by diligent A&Ps over the last 8 years that I owned it and this was never discovered. This plane was plans built and the torque tube was constructed by the builder and was not a Sonex part. The plane had been kept outdoors for some time before I bought it and was subject to rain and wind. The tube was also painted black which made the damage somewhat less noticeable at a casual inspection.

Guys, be careful out there...these things really will try to get you if you let them.

Charlie

[vwglenn]

Wow! Good thing it was found.

Many moons ago, I worked in the maintenance department of a large FBO. After being involved in the annual inspections of several aircraft over the years and seeing the money flow, I made the determination that a hangar is money well spent. Consistently, the maintenance requirements of aircraft which were stored on tiedowns were 50-100% more than those who lived inside. As a result, I will not own a plane unless I can keep it inside.

[kmacht]

It would be interesting to see pictures of exactly where the rust and decay was located if you ever get copies of them. The torque tube there is one of the places I always check when pre-flighting. I'm usually looking to make sure the nut is still installed but a check for rust wouldn't be a bad idea.

I agree that hangers are great but when you live in an area where they are $600+ a month for the money you would end up being able to buy a new sonex every 3 to 4 years compared to a $50 tiedown. The nice thing about the Sonex is that there is very little hidden that can't be carefully inspected every year.

Keith
#554

[radfordc]

Here are pics of the damaged torque tube. Hard to say how long it would have taken before a total failure occurred, but it's not good for sure.

[NWade]

Wow. Looks like whatever paint or coating was put on those parts, it didn't seal the steel like a good powdercoat would...That sucker is rotting *everywhere*! :-/

--Noel

[ihab]

Looks like whatever paint or coating was put on those parts, it didn't seal the steel like a good powdercoat would...That sucker is rotting *everywhere*!

Indeed -- but also, there is a lot of rot going on around the rivet holes. What do people do with their steel parts after match drilling? Does the powdercoat ever craze or crack where holes are drilled? Is it prudent to squirt a dab of primer into the holes before riveting into place?

Ihab

[SonexN76ET]

PLEASE NOTE, THIS TORQUE TUBE WAS NOT A SONEX SUPPLIED PART AS PER THE ORIGINAL POSTER OF THIS THREAD.

[ihab]

THIS TORQUE TUBE WAS NOT A SONEX SUPPLIED PART

If that referred to my comment, then absolutely -- understood! ;) The question stands, though, as to what can be learned from this. (I cannot afford to rent a hangar where I live, and I suspect many others can't.)

Ihab

[radfordc]

You can see in the photos that there are two small holes drilled in the tube. These apparently allowed water to collect inside the tube and led to the tube rusting from the inside out. In the "old days" steel tube planes often had the tubes filled with linseed oil and were then sealed so that no moisture could enter.

[Pickleman]

Might an examination of the other pushrods in the aircraft be prudent? I have seen brand new chromoly tubing clean on the outside yet rusted on the inside when the outside had been fogged with a preservative but not the inside.