Walt
Well Known Member
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).
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).
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