RV-7A Question

RV10 4JF · #1 11-06-2007, 06:42 AM

A friend of mine is doing a condition inspection on an RV-7A and found what may be a problem in the aileron pushrod rod end. The rod end attaches to the pilot?s stick and it has about a 1/8? play on the bolt that attaches it to the bracket. It seems like too much play and we wonder if there is something missing with this installation. He does not have the plans for the airplane. If any member can provide some guidance here, I will appreciate it.

Also, just info, I tested out the static system as the owner reported a possible static system leak. I found a massive leak that turned out to be the plastic tubing had slipped off the rivet used as the static source. The static tubing was just hanging next to the rivet and from a distance it appeared to be attached. The tubing installation did not have any type of support and it was held in place by a short tubing that attached to the rivet.

Thanks, JF

Jamie · #2 11-06-2007, 07:35 AM

I believe that bolt you're referring to should have two washers, one on each side of the bearing. What you're describing is definately NOT right, as the bearing should be held in there tight and should not rotate around the bolt.

robertahegy · #3 11-06-2007, 04:39 PM

There are two tiny, but thick washer that go in there. The washers are thick but have an OD that is only slightly larger than the ID. They are kinda shiney, too. The part number is 5702-75-60 and the bearing should have one on each side.

Roberta

RV10 4JF · #4 11-07-2007, 06:42 AM

Thanks both for the reply and also for that part number. My friend had decided to add washers to the installation but having the correct part will be much better.

Thanks again, JF

LettersFromFlyoverCountry · #5 11-07-2007, 07:18 AM

It's not clear to me what part you're all talking about. Could you provide a DWG number so I can double-check this on my project?

robertahegy · #6 11-07-2007, 06:51 PM

Bob, For the 7(A) it's drawing 38 in the LL corner.

Roberta

rvbuilder2002 · #7 11-07-2007, 07:34 PM

that you use the correct washers that Roberta listed.
If you do not, the regular washers will crash on the rod end when the stick moves for and aft to the extreems in pitch (the rod end rolls from one side to the other when the control columb move fore and aft.

L.Adamson · #8 11-07-2007, 09:06 PM

Quote:

Originally Posted by rvbuilder2002

that you use the correct washers that Roberta listed.
If you do not, the regular washers will crash on the rod end when the stick moves for and aft to the extreems in pitch (the rod end rolls from one side to the other when the control columb move fore and aft.

With my 6A, the original plans did not have these washers. Later plans had the change. I purchased some from Van's and attempted to install them.

It spread the fork to the point, that the bolt would no longer go through. I removed them, and there is still plenty of movement, with the stick in all positions. I went out of my way to make sure the rod-bearing has a neutral position, when the ailerons are neutral.

Any thoughts on this?

L.Adamson

rvbuilder2002 · #9 11-07-2007, 09:47 PM

Quote:

Originally Posted by L.Adamson

With my 6A, the original plans did not have these washers. Later plans had the change. I purchased some from Van's and attempted to install them.

It spread the fork to the point, that the bolt would no longer go through. I removed them, and there is still plenty of movement, with the stick in all positions. I went out of my way to make sure the rod-bearing has a neutral position, when the ailerons are neutral.

Any thoughts on this?

L.Adamson

Since the up elevator travel on RV's is recommended to be more than the down travel you probably are binding the rod end at one extreem or the other since you set it up for when the stick is neutral.
Moving the stick left or right also effects the clearance.

The absolute check, is to move the stick to the extreem four corners of the travel range and verify that the aileron pushrods still have a small amount of rotation left at each position (rod ends aren't bound up).
On some airplanes it is very difficult to prevent binding at all four corners. What is often done is except a minor amount of binding at the extreem forward corners of travel. It is extreemly unlkely that full down elevator and full left or right aileron would ever be used at the same time.

This problem is most prevelent in RV-6's or 6A's because of the different style aileron bellcranks used. The problem does not exist in the tandem seat RV's because of a totally different style control system.

L.Adamson · #10 11-07-2007, 10:38 PM

Quote:

Originally Posted by rvbuilder2002

Since the up elevator travel on RV's is recommended to be more than the down travel you probably are binding the rod end at one extreem or the other since you set it up for when the stick is neutral.
Moving the stick left or right also effects the clearance.

The absolute check, is to move the stick to the extreem four corners of the travel range and verify that the aileron pushrods still have a small amount of rotation left at each position (rod ends aren't bound up).
On some airplanes it is very difficult to prevent binding at all four corners. What is often done is except a minor amount of binding at the extreem forward corners of travel. It is extreemly unlkely that full down elevator and full left or right aileron would ever be used at the same time.

This problem is most prevelent in RV-6's or 6A's because of the different style aileron bellcranks used. The problem does not exist in the tandem seat RV's because of a totally different style control system.

In all reality, the stick might have not been neutral. I know that I made a point of getting stick travel & having the rod end move side to side without hitting. However, I'll go back & re-check.

L.Adamson