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SB 99-06-1 Overhead Rudder Pedal RV-6

T

Tango Mike

Well Known Member
Found some cracks and need the kit, part number WD-655 FPKIT, but searching the web store fails to bring up any matches.

Has anyone installed this kit recently to complete the SB?
 
If by recently you will accept "five years ago" as an answer, then yes. I fabricated my own reinforcements from some sheet stock I had, and a good friend with a steadier welding hand than I welded them on for me.

On my -6, the failures occurred where the joints were in compression... The backside of the pilot's right pedal, and the front side of the passenger's right pedal. Thankfully I found them before the cracks became failures.

The SB says the reinforcing tabs should all go on one side, if I recall. This is easier to visualize, and probably "over-reinforces" all of the joints anyway. But it does not orient them all to the side where the maximum stress occurs. If you want to take the time to do that, you want them on the aft side of the outboard pedals (left foot pilot, right foot passenger), and on the forward side of the inboard pedals (right foot pilot, left foot passenger). You'll need to size them carefully to make sure they clear the adjacent bar when they're all assembled again.
 
Great information, thanks.

I'm not a builder with the skills/tools to fabricate my own patches, but friends of mine can, which I'll have to do if the kit is no longer available from Van's.

I haven't seen the instructions, but the one-page SB does indicate that all the patches go on the firewall side of the pedal where a divot, described as distortion (bulging or caving in) appears on the forward side of the torque tubes.

I'd be interested in the reasons for your statement that this solution doesn't orient them all to the side where the maximum stress occurs.

Thanks again for taking the time to offer assistance.
 
You might consider contacting Russ McCutcheon. He lurks here. McCutcheon Metal Fabrication does all of the RV rudder bars and many other weldments. I was there a couple weeks ago and they where welding the tabs on at the time. He had a stack of rudder bars headed to Van's for the next generation of kits.
I would ship it to him in a heart beat and have his company take care of it. Super good guy and I bet you get it back in no time, done right, by someone who has done hundreds of them.
I am an ok welder and do my own stuff for jigs, art, tools, whatever.... but when it comes to my airplane or trickier things, I take it to Russ.

I am always shocked when I hear there are still airplanes out there that have not had this done. Somebody isn't checking SB's when doing CI's. Of course, they could be making a conscious decision. SB's are not mandatory. I wouldn't wait to find a crack on this particular one though.
 
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Thanks for the suggestion, but I've ordered the kit from Van's and trust a very experienced local welder to do the job right.

The problem now is getting the pedal assembly out. I've got it completely loose, but neither of the two side UHMW blocks is split like the center one and I've not not been able to manipulate the pedals so one end will clear obstructions and allow me to angle it fore-aft or up-down to remove it with the blocks still in place.

Looking for solutions here in central Texas while keeping an eye on the skies. . .
 
Tango Mike said:
Thanks for the suggestion, but I've ordered the kit from Van's and trust a very experienced local welder to do the job right.

The problem now is getting the pedal assembly out. I've got it completely loose, but neither of the two side UHMW blocks is split like the center one and I've not not been able to manipulate the pedals so one end will clear obstructions and allow me to angle it fore-aft or up-down to remove it with the blocks still in place.

Looking for solutions here in central Texas while keeping an eye on the skies. . .
Click to expand...

You have to get it repositioned so that you can get a block off of one end..... reposition again, so you can get the other block off.... then remove the assemblies one at a time.
 
rvbuilder2002 said:
You have to get it repositioned so that you can get a block off of one end..... reposition again, so you can get the other block off.... then remove the assemblies one at a time.
Click to expand...

Pull all the fasteners out, then slide the entire assembly as far aft as you can. The farther aft it goes, the wider the fuselage is, which gives you room to pull off a bearing block from one end. Get the first one off, and the other one is easy. Replacing the assembly is as simple as reversing the process.

Once apart, some have used a bandsaw to slice the blocks in half (like the center one) so you can refit everything without all of the contortions.
 
Service bulletin

I just completed this service bulletin last weekend. It started with badly leaking master cylinders, and I figured while I was down there..... It was a lot of work getting the torque tubes out. My naca duct was mounted very close to the tubes and in my manipulating one naca came off, so I was able to use that hole in the side of the fuse to help get the block off and manipulate them in and out. It still took me several hours upside down to get them installed correctly and all of the cotter pins in, do everything you can outside. Pay close attention to where the master cylinders mount on each pedal, or else you'll be re setting them while on your back, ask me how I know! Brakes are better now except the left pedal isn't retracting well so I'll be working on that later this week. Good luck.
 
Yep, it can be a pain getting the pedals out of the plane, but eventually they come out. It may be a couple days before you can walk erect, however.....

By all means split the blocks prior to reinstallation. Put a washer on each bolt between the block halves to compensate for the saw kerf. This will maintain the proper bearing clearance in the blocks and prevent them from tightening up on the pedals. Putting everything back together is quite easy.
 
Great explanations, guys, thank you. After hours of fruitless effort today, I'll be able to crawl under there tomorrow and continue the battle.
 
Tango Mike said:
I'd be interested in the reasons for your statement that this solution doesn't orient them all to the side where the maximum stress occurs.
Click to expand...
It's because the joint failure generally occurs on the side of the tube that is in compression when the pedal is loaded.

Consider the pilot's right foot pushing on the right rudder pedal: That push places the forward side (closest to the firewall) of the pedal in compression. At the same time, it places the *aft* side of the passenger's rudder pedal in compression, because the rudder cable is connected to the bottom of the passenger's right rudder pedal.

The same is true for the left rudder weldment, but in general, given that most of the time only the pilot actuates the pedals, and most of the time the pilot is in the left seat, these failures will show up first on the right pedal weldment.
 
Snowflake said:
It's because the joint failure generally occurs on the side of the tube that is in compression when the pedal is loaded.

Consider the pilot's right foot pushing on the right rudder pedal: That push places the forward side (closest to the firewall) of the pedal in compression. At the same time, it places the *aft* side of the passenger's rudder pedal in compression, because the rudder cable is connected to the bottom of the passenger's right rudder pedal.

The same is true for the left rudder weldment, but in general, given that most of the time only the pilot actuates the pedals, and most of the time the pilot is in the left seat, these failures will show up first on the right pedal weldment.
Click to expand...

That makes perfect sense, but only after you explained it. Thank you.

In other news, I just got the pedals out, but the answer wasn't to have both sides as far forward as possible. Two cables (purge valve on the left and cabin heat on the right) interfered with being able to do that. What finally worked was with the left side as far forward as it would go with the right as far aft, and simultaneously pulling inboard on the front pedals while pushing outboard against the front edge of the right block. The right end of the tube popped out so quickly that I it took a moment to realize I'd managed to do it.

Thanks again for coming to the rescue.
 
Kyle Boatright said:
Absolutely correct. The answer was to slide them as far AFT as possible, which was what I wrote a few posts ago. ;)
Click to expand...

And I knew that when on my back in the airplane and had a brain malfunction when typing that.

The point I was trying to make and failed to do so, is that because of the two cables, both of which are secured by jam nuts I couldn't get to, bringing both ends of the pedals aft didn't give me enough room to slip a block off either side. But with one end as far forward as possible and the other as far aft as possible, I was able to release the front tube from the aft block.

Not the usual way, apparently, but it worked.
 
Tango Mike said:
And I knew that when on my back in the airplane and had a brain malfunction when typing that.

The point I was trying to make and failed to do so, is that because of the two cables, both of which are secured by jam nuts I couldn't get to, bringing both ends of the pedals aft didn't give me enough room to slip a block off either side. But with one end as far forward as possible and the other as far aft as possible, I was able to release the front tube from the aft block.

Not the usual way, apparently, but it worked.
Click to expand...

Glad you got 'em out. Standing on your head, struggling to remove an assembly (or trace a wire) is one of the miseries of aircraft ownership.
 
Tango Mike said:
But with one end as far forward as possible and the other as far aft as possible, I was able to release the front tube from the aft block.

Not the usual way, apparently, but it worked.
Click to expand...

Depends on who you talk too....
That is the way I always do it, but there are a lot of differing opinions here which is why I originally just said re-positioned to allow removing a block....
 
Tango Mike said:
But with one end as far forward as possible and the other as far aft as possible, I was able to release the front tube from the aft block.

Not the usual way, apparently, but it worked.
Click to expand...
The builder of mine was considerate enough to split the blocks, which made it simple to get the tubes out of the blocks. However, they didn't have the forethought to run all of the cables *above* the cross-tubes between the panel and the firewall, so getting the weldments out of the cockpit required some fancy geometry that I (of course) didn't document after removing. There were some choice words uttered while re-installing the newly welded, and newly painted, parts, as they picked up their first scratches... :(
 
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