Sheared Rudder Stop

Nick Leonard · #1 12-03-2013, 12:03 PM

It started when my rudder gust locks came loose on one side during a high wind allowing the rudder to slam against the right rudder stop (RV-10). This completely sheared off the horizontal rudder stop...that's three #4 rivets sheared like "butta". I would never have thought that you could slam the rudder hard enough to shear off three rivets.

Because of the challenge of squeezing in three new rivets in the confines of the rudder rod end bearing plates, I chose to install three rudder stop plates sandwiched between the upper and lower plates. Recall that the rudder is attached with three rod end bearing with bolts that drop down between two plates attached to the spar of the vertical stab. Originally the rudder stop was riveted to the top of the two plates with three rivets. I now have three stacked plates held with #6 screws that go through both the top and bottom plates (plus a spacing washer).

I now have the thickness of three stop plates instead of one and steel screws instead of aluminum rivets held in at the top and bottom instead of the top only.

Of course, the real answer is to be sure that you have good gust locks that will stay in place in a high wind (like we had go through Oshkosh this past year). I just wanted to share what that wind can do to your airplane. I'm still amazed that it could shear clean through the three rivets!

pierre smith · #2 12-03-2013, 01:34 PM

Happened to me as well, Nick. I made a piece of UHMW that fit between the brackets...fixed.

Best,

rleffler · #3 12-03-2013, 02:07 PM

Quote:

Originally Posted by pierre smith

Happened to me as well, Nick. I made a piece of UHMW that fit between the brackets...fixed.

Best,

I purchased one of the stops that Craig Vincent was selling, which is similiar to Pierre's solution. It's held in place with a couple of AN3 bolts.

I think somebody else started selling them, but I can't recall who at the moment.

380mxc · #4 12-03-2013, 02:17 PM

Having the rudder stops shear off may not be a bad thing. It is a good indicator
abuse may have taken place and the assembly should be inspected.

rockwoodrv9 · #5 12-03-2013, 02:34 PM

Considering the possibility of damage from similar wind damage to a HS that could be related to big problems, please inspect the **** out of all the parts with even a remote chance of damage.

Quote:

Originally Posted by 380mxc

Having the rudder stops shear off may not be a bad thing. It is a good indicator
abuse may have taken place and the assembly should be inspected.

DanH · #6 12-03-2013, 02:41 PM

It sheared three rivets to remove the standard stop, and you're thinking the internal plastic stop is better? Have you looked at the geometry?

PerfTech · #7 12-03-2013, 02:43 PM

....I have in hand our finished prototype RV-10 gust lock. I am taking it to the airport today for test fit and give final approval to start manufacturing. The design is very much like our other models with provisions for the curved stick and a unique anchor at the control stick. You guys with the RV-10s are going to love this new accessory. Will post photos and a video very soon. Best all, Allan...

Steve Melton · #8 12-03-2013, 03:21 PM

I've used Allan's gust lock on my 9 for the past couple of trips. I like it.

BobTurner · #9 12-03-2013, 03:41 PM

This has happened to quite a few planes. Some builders are now just putting in steel screws instead of rivets, right from the start.

As mentioned, it is important to have a good gust lock and use it every time. It doesn't take much wind to bang the rudder around. I 'stole' the design which was posted here, a small modification to the Boggart (spelling?) tow bar. Since I carry the tow bar everywhere, this adds no extra weight to my load. I've pushed and shoved the rudder pretty hard, I don't see how this gust lock can fail (unless the cables themselves break).

Also as mentioned, it is important that you carefully inspect everything in the tail for any possible structural damage.