Desperate for rudder help.

[mtbowhunter]

Hello everyone:

I have a RV9 that I purchased complete. I have owned it for just over a year. It has been an awesome flyer. The 2nd most impressive thing about the plane to me, after the incredible speed, was how true it flew. Once trimmed for cruise, it was literally a hands off plane.

In April, I had the local A&P shop do an annual on it. When they were moving it from my hangar to theirs, they were pulling it by the tailwheel with the tug. I do not have gust locks on the rudder or elevator and on the day they decided to move it the wind was gusting past 40. Why they chose to move it on that particular day is beyond me. According to the fella that was moving it, a strong gust came up at one point and drove the rudder to the right so hard that it slammed it into the inside corner of the elevator, which was blown downward at the time. The corner of the elevator punctured the right side of the rudder where the two came into contact.

It seems obvious to me that in order for this to have occurred, the rudder must have flexed beyond the stop because the two will not normally come into contact. The entire tail section was carefully inspected during the annual and no damage was found beyond the small puncture on the lower right side of the rudder, which was then repaired with a very small amount of adhesive compound (probably no more than an ounce). The rudder does not appear to be bent and the aluminum is not kinked or wrinkled anywhere that anyone can see.

Unfortunately, since then the plane will not fly straight without constant left rudder. If you let up on the left rudder it yaws to the right and the left wing comes up, putting you in a righthand turn configuration.

The tail section has been closely inspected numerous times since the incident by the same shop that performed the annual and they say they can find nothing visibly wrong, aside from the little puncture that was patched. These are decent people who I believe are genruinely trying to figure out what happened. It is getting very frustrating though.

I am sorry for the long post, but does anyone have any insight to what might be causing this or how to fix it? Thanks for any help.

Joe.

[civengpe]

Have you gone through and checked the rigging? With that much force applied to the rudder, it may be possible that it may be out of rig.

I am just in the beginning process of building my RV, so don't know the ins and outs of them, but I did have the exact same symptoms on my Cherokee and it turned out to be the rudder rigging.

[N427EF]

Seeing that you are quite desperate to get your 9 back to flying straight again,
I would offer the following advise.

From what you describe it is quite likely that your rudder is slightly bent
or curved from the collision with the elevator.
A wedge or a tab on the rudder would probably solve the constant need
for rudder in cruise, however in this case that is a "fix" not a repair.
I take it from your writing that you will probably not be happy until your 9 flies again like it used to.
Soooo.
By now you have friends in the RV community and you could ask someone to help you build a new rudder. My guess is it would take less than a couple of hundred dollars and less than a full weekend to build a new one.
Hang it on your 9 before you paint it and I am almost certain it will fly just as straight as it used to.
Let us know what works for you.

[mtbowhunter]

Civengpe:

Thank you for the advice. I am not in the slightest bit mechanically inclined and therefore wouldn't even know how to check the rudder rigging, but I will pass your suggestion along to the A&P.

Ernest:

My first reaction was also that the rudder must be bent. The A&P tells me they have used some sort of a measuring device (again, I am not as literate in the mechanical aspect of the airplane as I'd like to be) and are sure that that the rudder isn't bent. Your thought is the same one I had though, just take off the old one and replace it completety. But if they are saying it's not bent, I am hesitant to do that for fear that the problem still might exist after it's done. Thanks for the advice.

Joe.

[hydroguy2]

Joe, can you fly it to Townsend? OR if not would you like me to come look at it? I built my -7 so might be able to see something the A&P(non builder) is missing.

Also have they checked the elevator for any twist? or misalignment between the two sides. Impact enough to punch the rudder may have flexed something else. Need to look at the flaps and ailerons also....hangar rash happens

Brian
Townsend, MT (8U8)

sending a PM with my phone number

[guccidude1]

Joe: Nice guys or not, they bent your airplane. They have a responsibility to make it right, to your satisfaction. The normal tendency, assuming no trim tabs, for an airplane is to require right rudder or little or no rudder at all in cruise, hence the small metal trim tab mounted on the rudder of most production aircraft. You have stated you now require left rudder to pick up the right wing, if I understand you correctly. Your rudder is warped, most likely to the left and acting as a trim tab to move the rudder to the right. The warping probably occurred during impact or attempts to straighten the rudder after impact. Your only correct way to solve the problem it is to replace it. Many of the original parts can be salvaged, the rod end bearings, lock nuts, and nut plates, and the fiberglass top and bottom caps, for example. I would replace the structure, trailing edge wedge, and skins. All of these items can be purchased at Vans and shipped via UPS to your door. You can assemble yourself, pay to have someone else assemble, or since they are airplane mechanics, they should be more than qualified to read plans and drive rivets. You might even be able to find a spare rudder kit on this forum. But remember, it is the mechanics responsibility to make it right at no cost to you other than a reasonable build time of a week or two.
As I was writing this, it occurred to me that since the rudder impacted the right elevator, it might be damaged also. It wouldn't hurt to take a close look at it for undetected damage or warping. Dan

[mtbowhunter]

Again, I thank all of you for your much needed help. As I understand it, they have also looked over the elevotors and the wings for twist or misalignment and have not found any. Your responses reinforce my belief that something must have gotten bent and that doing things like adjusting the trim tab or checking the alignment of the wheel pants and the fiberglass covers on the gear legs is simply ignoring the elephant in the room.

Joe

[terrye]

If the rudder is bent enough so that it does not fly straight anymore, this should be obvious on inspection with a straightedge. This can be done on the airplane, but it would be easier with the rudder removed. Place it on a flat table left side down and measure, then right side down and measure. It could be twisted.

Also if you have the rudder removed, be sure to check that the elevators are true. With the counterweights fixed to the horizontal stabilizer, lay a long straightedge across the trailing edge to see if the elevator got bent.

Building a new rudder is not really hard, all of us building these planes started on the vertical stabilizer and then the rudder. Many of us did not have previous building experience. Don't be afraid of building a new control surface if it is bent.

[Steve Barnes]

Some builders have installed a plastic internal rudder stop which is hidden away but gives a great leverage advantage when the rudder is pushed from side to side. Though the rudder may show no signs of being bent, the nut plates that hold the rod end bearings may have been bent askew on the Vertical spar. Just something else to look at.

Steve Barnes "The Builders Coach"

[Russ McCutcheon]

Originally Posted by Steve Barnes

Some builders have installed a plastic internal rudder stop which is hidden away but gives a great leverage advantage when the rudder is pushed from side to side. Though the rudder may show no signs of being bent, the nut plates that hold the rod end bearings may have been bent askew on the Vertical spar. Just something else to look at.

Steve Barnes "The Builders Coach"

As I was reading this thread this was the answer that came to me also, it does not take much either and it would do exactly what you?re describing, still it would require building a new rudder more or less.