Listen to the sounds your airplane makes....it may save your butt.

[Walt]

While doing a panel upgrade and condition inspection on an RV4, I was hearing a very slight scraping sound when the stick was pushed full forward, obviously one of the elevator torque tubes was hitting something in that position and for a moment, I considered letting it pass, it's was one of those things you say to yourself how often does one really use full down stick so is it really a problem. After locating the area I found it to be under the passenger floor pan which of course is riveted down and the flap mechanism is bolted on top of it, so this was not going to be a 5 minute job. But letting it go kept nagging at me so I decided to just tear into it and find out where the interference was, have a "quick" look at the tube to be sure it wasn't damaged and grind off the offending material.

Well to my surprise (and relief) when I finally got access to have a look I was glad I did, the torque tube had a huge gouge in it that looks to be most of the way through the tube

So new parts are on order and this is one that I'm really glad I took the time to have a look before it got worse... much worse.

So what to take away from this, don't let anything go that doesn't feel or sound right, find out what it is and correct it.
This is absolutely mandatory for flight controls no matter how "minor" it seems!

Controls should move from stop-stop (this means HIT the stops) with absolutely no binding or funny scraping noises!

BTW, this isn't the first time I've had to replace torque tubes due to damage from chafing on structure but this one was probably the worst/scariest (you may survive a broken aileron tube but the outcome of a disconnected elevator is probably going to make for a really bad day).

[aerhed]

For all the times you dug into something and went "huh, nothin". Then you get the payoff with one like this.

[David-aviator]

Good catch Walt...the owner owes you a couple tall cold ones.

[deene]

My old friend, Tony Bingelis said it this way "machines are always talking to you, you have to learn to listen".

[scrollF4]

Originally Posted by deene

My old friend, Tony Bingelis said it this way "machines are always talking to you, you have to learn to listen".

Well said.

Walt, that was an awesome catch. Well done, Sir.

[cfiidon]

I had a similar issue this past week. I noticed one day that my elevator was sticking ever so slightly in the full up position. Not too much, but just not quite right. Hmmmmm....
I tore into it starting at the elevator bearings working forward to the rod end-elevator connection. no problem there. The pitch servo connection and rear bullhead interconnect looked okay.
I found it at the rear stick. The forward pitch tube rod end bearing AN3 bolt protruded a little to far. When the stick was back (elevator up) the bolt threaded tip was touching the interior of the weldment and sticking ever so slightly.
One washer under the bolt head fixed that.
It must have been that way for 130 hours and I never noticed before. Colder weather???
Anyway, she squawked - I listened.
Don

[Steve Melton]

Walt has the knack!

[Walt]

Originally Posted by deene

My old friend, Tony Bingelis said it this way "machines are always talking to you, you have to learn to listen".

My wife always laughs at me when I say machines have souls and we need listen to them when they talk

Originally Posted by cfiidon

I had a similar issue this past week. I noticed one day that my elevator was sticking ever so slightly in the full up position. Not too much, but just not quite right. Hmmmmm....
I tore into it starting at the elevator bearings working forward to the rod end-elevator connection. no problem there. The pitch servo connection and rear bullhead interconnect looked okay.
I found it at the rear stick. The forward pitch tube rod end bearing AN3 bolt protruded a little to far. When the stick was back (elevator up) the bolt threaded tip was touching the interior of the weldment and sticking ever so slightly.
One washer under the bolt head fixed that.
It must have been that way for 130 hours and I never noticed before. Colder weather???
Anyway, she squawked - I listened.
Don

Although I appreciate the Kudos I really didn't make this post because I need another pat on the back or "great job walt".

If I can inspire just one post like Don's above that is my intent.

The fact is some folks build spectacular airplanes while others probably should have found a different hobby. I only get a chance to look at small number of RV during the year and I find what I consider serious problems on probably half of them. So I'd like to see folks take their maintenance more seriously.

As that old saying goes:



Happy Holidays!

[sblack]

Another reason to make floor pans removeable

[Skykingbob]

Thanks for the post to give us all another slap in the face to wake up
and get a reality check!! Great Christmas present that will help make
for a better New Year!

Merry Christmas Walt!!!