M

mtbowhunter

Member
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. :mad:

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.
 
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.
 
Trying to help

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.
 
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.
 
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
 
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
 
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
 
Check elevator rigging too

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.
 
Internal or External rudder stops?

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"
 
Steve Barnes said:
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"
Click to expand...

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.
 
Take Brian up on the offer to look at your airplane. As someone who has built a rudder etc. before, he will undoubtedly know more than the local A & P. And like others have said, it is relatively easy to build (or even buy) a new rudder. I would, however, make sure it isn't something else (like the rod end bearings etc.) that are the problem.

My thought is that if the rod end bearing plates got bent, it would either be obvious or not. If not obvious, then the shift might be just enough to throw the plane out of rig, and it might be made to fly straight just by re-rigging. That, of course, does not make it "right" but would at least fix the problem while you decided what other steps to take.

And yes, a lot of people with the same experience as you have built beautiful airplane parts and airplanes, so certainly you could build a rudder in short order with a bit of help from a local builder who has the appropriate tools.

Good luck.

cheers,
greg
 
I would definitely check into damage to the vertical fin, it may have warped the fin or possibly even damaged the mounting points,,,that is alot of leverage applied to that structure.
 
Any chance another rv-9 rudder can be installed and tried. I don't know how close these planes are built from one another but could there be a loaner out there to see if it changes flight characteristics? Maybe someone in an annual right now?
 
absolutely

A loaner rudder from another 9 ( or a 7 for that matter ), should be a simple bolt on.



Strasnuts said:
Any chance another rv-9 rudder can be installed and tried. I don't know how close these planes are built from one another but could there be a loaner out there to see if it changes flight characteristics? Maybe someone in an annual right now?
Click to expand...
 
Don't lose sight of the fact that they damaged your aircraft! Do whatever it takes to put it back to where it was. This will not be a cheap repair when you consider the paint, and paying someone to re-build the rudder and possibly the horizontal/trim tab/elevator. They need to make this right.
I suspect that the rudder stop could have caused damage to the lower hinge or the attachment point since they can find no damage to the rudder itself.
 
Thank you all so much. There is so much more information in these posts than I could have ever hoped for. I am going to print them off and provide them to the A&P shop because there are many things here that I don't think they've considered. I have also emailed with Brian as a sort of next step if the shop here can't or won't get it right. Thank you again. I will let you all know what happens.
 
Joe,

One of my -7 projects (same rudder as the -9) needed rudder trim to fly straight. The stunningly amazing thing is the yaw sensitivity of the trailing edge. I could literally move the ball 1/2 the cage by running my hand with some pressure up one side of the rudder trailing edge or the other as needed. You could not see the difference; nonetheless it was effective. With the immense whack to your rudder, I'm not surprised your plane is so out of trim.

Along with others, I suggest holding the shop's feet to the fire. They should replace the damaged rudder with a new one they obtain (build if necessary) immediately. Patching the skin doesn't correct a bent rudder. See how that works. I rather doubt there's damage beyond the rudder, but they should carefully inspect the entire empennage.

Where is your airplane located?

John Siebold
 
Joe and I have been in contact. We will get this right. I have only built 1 RV, but have plenty of friends and experience around here to get his plane back flying as new.
 
Patch

It takes only a small amount of irregularity on the trailing edge of the rudder to make the plane yaw the other direction. Are you certain the patch is not causing a disturbance like a trim tab?
 
Extra:

I also wondered that and asked the question right away. The A&P said he didn't think so because it was such a small amount, but he said he was going to call Vans and ask them. After all the responses I received on this post, I am going to meet with him tomorrow and talk about all the suggestions, including the effect the patch may be having.
 
When the rudder hits the rudder stop, it should stop and not hit the elevator. If the rudder hit the elevator, something got bent or warped. If the rudder has a hole punched in the skin from contacting the elevator, it has been damaged more than a simple little hole.

The airplane should not be flown until it is determined how the rudder made contact with the elevator. Something had to give for that to happen.

We do not need another vertical stabilizer/rudder failure in flight.
 
Not uncommon though unfortunate

I have seen several RV's with rudder damage as described. In fact the factory RV-9A has a dent in the rudder if I recall correctly. Obviously a lesson learned is to use a rudder lock when the aircraft is unattended.

One thought, is your problem rudder related? What I mean is that you mentioned the AP was performing an inspection. Did they remove the gear leg fairings? If so could they have been reinstalled and out of alignment slightly?

Just a thought.
 
David-aviator said:
When the rudder hits the rudder stop, it should stop and not hit the elevator. If the rudder hit the elevator, something got bent or warped. If the rudder has a hole punched in the skin from contacting the elevator, it has been damaged more than a simple little hole.
Click to expand...
The gap between the rudder and elevator corner is not that great if you go by the max recommended deflection. I made my max deflection a tad less just for the same reason, yet a hard gust of wind could still flex the rudder enough to make contact. A friend of mine got a ding in his rudder just that way but to punch a hole in the rudder, it must have deflected a great deal more which means more bending.
As others have said, I also believe your rudder has slightly bent/twisted that it might be hard to detect with naked eye but due to sensitivity of the rudder a small amount of twist could cause it to yaw.
The rudder can easily be detached and unless they can show with good method that there is no bend/twist or any other damages to the rudder, building a new one is the safest bet and it can be done fairly quick with not a great deal of $$$$
No reason to short change your nice airplane.
 
Here's an update to all of you who provided advice. I printed off each of your comments and took them to the FBO and had a discussion with A&P regarding them. In light of the valuable input each you provided, I think he is finally convinced now that there is an issue with the rudder even though everything appears straight in an visual observation. He is taking the rudder off to look for a bend or twist that may have occured. Thank you all once again.

Joe.
 
You must log in or register to reply here.