Made a mistake, Help

I have my stabilizer completed and I have found a mistake. I trimmed the HS-301 skins even with HS-303 spars. I didn't notice the overhang of the skins until I was fitting up the right elevator. It isn't shown on the main stabilizer drawing and I missed it.

So how do I fix? Can I add a gap seal strip of say .016 on the top and bottom of the stabilizer? Any suggestions other than replacing the skin would be helpful.

Andy

No real fix...

This has happened before. Common opinion is that the overhang serves little purpose other than aesthetic, and perhaps a bit of drag reduction.
There is no fix that I am aware of short of replacing the skin.

proppershope said:

Can I add a gap seal strip of say .016 on the top and bottom of the stabilizer? Any suggestions other than replacing the skin would be helpful.

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I would drill out the skin-to-rear-spar rivets, slip a gap-seal strip under the skin and re-rivet.

Thanks Mel,

I think your idea is the best way to solve this. I hate to drill out all the rivets but that's the price you pay. I may even add a little to try to get a better gap seal. Have to think positive about these things. Thanks Mel.

Andy

proppershope said:

I may even add a little to try to get a better gap seal. Have to think positive about these things. Thanks Mel.
Andy

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Not sure what "today's" plans call out, but in the past, you were to leave the skin long and trim until you have a small clearance with full control deflection.

5/16" I believe, (but dont quote me on that!)

Mel said:

Not sure what "today's" plans call out, but in the past, you were to leave the skin long and trim until you have a small clearance with full control deflection.

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I dont have my plans as they went with the project, but they do call it out.
I would never argue with Mel (God of all technical RV stuff), and I am not going to now, but you might want to wait.
I have seen it done both ways, with the gap left as is, and with the gap seal put in. Without-hardly noticeable, with-sticks out like a sore thumb. I am not sure why.

What you may want to do is move on and build your elevators. Then, check them out without the seal and see if you can live with it. Again, I am not sure how much the gap can impact drag or other aerodynamic qualities, something you should check into. I suspect not much, but I just dont know. So I think you are dealing with a mostly aesthetic issue.

The bigger the gap, the more potential for airflow between the top and bottom sides through the gap. This reduces control effectiveness. By how much? I don't think anyone knows. I do know that in the past, Van's RV-4 had gap seals on the rudder and elevators. I believe it was to try and increase effectiveness at low airspeeds when he used to do an aerobatic routine in airshows.

FWIW

add a little

Now that I'm looking at the plans, the skin only extends about 1/2 inch aft of the spar. With the right elevator on the stabilizer it looks like I could extend the skin out almost 3/8 more, this would give me 7/8 of an inch before I would touch the elevator skin. The only way to be sure would be to set up the elevator travel and check at full deflection.

I like the idea of closing up the gap and maybe turning a mistake into something good.

Andy

I have seen this walking down the airshow flightlines and it seems to be no big deal. I have seen a few 3s flying with this issue.You could sell that tail and do it again thats what I did,and I did point it out to the buyer and he was ok with it and installed it on a rocket.