Tailfeather gap seals

[ak150crate]

Hi all,
I am getting ready to recover my tailfeathers and was watching the stewart systems dvd and noticed a gap seal on the horizontal of a citabria. It was just a simple tube that was the same size as the tube that the pin goes through for the elevator and was wondering if anybody has done this with a t-craft and if so did it make a difference in flight characteristics.

Thanks,
Matt

[cvavon]

Re: Tailfeather gap seals

Talk to the cub guys about this will make a big difference in low speed authority on the elevator and rudder look at cub crafters they make a product that jest pushes in shaped like hour glass this is on my lise of things for my plane

[swoeric]

Re: Tailfeather gap seals

yep gap seals are nice you can also use tape....I have used wrestling or gymnastics mat tape for this on my plane....its cheap and clear a role shuld last forever....you could probably also check mcmaster car or similar for extruded foam

[Larry Lyons]

Re: Tailfeather gap seals

There was talk about this earlier for the aileron. Has any body come up with a good way to to it. Not looking for more response as much as increasing cruise. L

[cvavon]

Re: Tailfeather gap seals

Larry I have thought about this also and i think the clear tape would also work on them or a light plastic that is L shaped and screwed to aileron bay cove and over lapping aileron so it can slip on top of aileron

[barnstmr]

Re: Tailfeather gap seals

Be careful out there... gap seals on tail feathers are one thing, but ailerons can be a whole different story... gap seals on ailerons can have odd results especially at high speeds... I don't think anyone really wants to flirt with flutter. Has anyone ever tested a Taylorcraft with aileron gap seals? I know two test pilots who got a rude awakening when testing them on a Cessna. Just be careful is my advice.

[cvavon]

Re: Tailfeather gap seals

thanks terry it is very far down my list of things to do ordered luscobe exhaust and heat muffs from doug coumbs for new engine today got carborator going together the last piece is starter and a B&C will jest fit on short mount by about 3/8 of a inch getting closer chuck

[Ragwing nut]

Re: Tailfeather gap seals

Do not do it on tcraft ailerons. The freise design requires airflow over both sides. You will not like the results

[cvavon]

Re: Tailfeather gap seals

How about Gurney flaps has any one looked in to them on flying tcraft there is a study on tcraft air foil

[N96337]

Re: Tailfeather gap seals

This is what I've heard as well... I think Bill Berle said something about aileron reversal? I just remember it wasn't something you wanted to do. Forrest might be able to shed some light there.

[3Dreaming]

Re: Tailfeather gap seals

On the clip wing I did we used a foam material and made an egg shaped leading edge on the elevator and rudder to fill the gap. The surfaces were covered and taped. Then the foam was added with a peice of finishing tape over it too.

[Hank Jarrett]

Re: Tailfeather gap seals

Guys,
Remember when you start messing with the control system you are moving into the Experimental realm. You are making yourself a test pilot in one of the most dangerous areas of testing (flutter testing is MORE dangerous, but messing with the controls is a great way to become a flutter test pilot). There is lots of history on reducing the turbulent air slipping through the gap on simple hinged controls (good side, better control authority, reduced dead band, better feel and sometimes even a little improvement in speed on both ends. The bad effects are less well known but could include a tendency to more PIO problems, changes in control forces and changes in behavior in stalls and slips.
The ailerons are a whole different kettle of fish (OK, quintal of fish for the Nufies). Terry is right when he says that sealing of modifying an aileron gap can be down right dangerous. DON'T DO IT! I'm not sure what the effect would be, mainly because I suspect that those who tried it might be DEAD! You also need to understand that an owner is NOT AUTHORIZED TO MODIFY THE CONTROL SYSTEM! If you got a tight a**ed fed on the ramp he might even apply that to clear tape on the tail hinges. When I get to the point of doing some actual aerodynamic testing on my plane (hey, that is how I have fun!) sealing the tail hinges is one of the changes I want to quantify and test, but I will do it with a real test plan and take real measurements so we know what is actually happening. Anyone who is curious might want to wait and not just blindly make changes to their planes. I will be happy to have others kick in with suggestions and analysis when I start my test plan.
Stay safe guys,
Hank

[ak150crate]

Re: Tailfeather gap seals

Thanks everyone for your responses. The ones on the Citabria looked so simple that I figured someone had tried it before and might have paperwork for it. Hank I would love to hear what you find when you do your testing.

Matt

[swoeric]

Re: Tailfeather gap seals

ok you can be official and cub crafters will sell you the tested stc for the gap seals....ps stay away from those ailerons nothing good comes from changing what we have

[skyboltone]

Re: Tailfeather gap seals

Friend o' mine mentioned he'd seen clear shelf paper somewhere. He couldn't remember where. I don't think there are many things out there that are UF proof except for that stuff they use on motor home decals you know? The big swirls and swooshes down the side of your Bounder? It comes clear on great big rolls at the local sign shop. Cut to size, pass it from the top thorough the gap and secure with another piece on the underside. Or so I imagine.