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air leaks under seat

moriches1

I'm New Here
i just purchased a rv-6 an now that it's getting cold i've noticed a lot of cold air comming from under the seats. i put aileron boots on help some but still got cold air comming in from somewhere. and suggestions?

thanks

dan carley
rv-6
432sh
 
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Which canopy do you have? I can't speak for the tip-up's, but most sliders have a pretty strong outflow leak between the canopy side skirts and the canopy deck. If you seal the outflow leaks, the inflow leaks (e.g. the crotch cooler) will be much less noticable.

To seal the area along the canopy side skirts, get a piece of pipe insulation - the stuff you'd slip on a copper pipe. It looks like an "O" in cross section and comes in 3' or 4' lengths. Cut the tubular insulation to the fit between the canopy bow and the blocks where the rear canopy pins engage. Then slit the insulation in half lengthwise. You want two "C" shaped pieces.

Next time you go flying slip a piece between the slider rail and the canopy skirt on each side after you've closed the canopy. You'll get a nice seal and tremendously reduce the airflow in the canopy.

Beyond that, you may have inflow leaks around the aft skirts if the skirts don't fit drum tight. Seal those with some weatherstrip attached to the turtledeck in a location where the aft skirt will crush the weatherstrip slightly when the canopy is closed.
 
I Have an RV-6A - Similar

We had the same problem and it was very uncomfortable for my wife. I put the boots on the aileron pushrods as Ken Scott described in the RVator and sealed all of the fuselage penetrations with RTV especially around the spar and main landing gear. I do not run any tubes through the side skins - I used bulkhead fittings and the tubes and hoses from both sides terminate at the fittings. If you pull the seat pans again and look for small openings I'm sure you will find some - I found several. If you have a slider there is a leak around the center slider rail which is a little tricky to seal. This is a low pressure area and it sucks in a column of cold air that finds its way down between the seats. I read about a sliding plug developed by Tracy Saylor and I did my own out of balsawood laminates topped with fiberglass. I have had many little problems with it and adapted the latest fix yesterday. Basically, the plastic slider block pushes the plug back when you open the canopy and a string pulls it into place when you close the canopy. I have used nylon wirebundle lacing tape and safety wire as the puller medium but the nylon is the way to go. I made two little eye-pins out of the finest safety wire (.020 I think) to tie the string (nylon lacing tape) to the plug. At first I tied doubled string to one pin looped it around the block bolt and tied it to the other pin with the canopy off and upside down so I could establish the exact closed position of the plug. You have to have a mating "hat" over the rail at the interface of the two rear skirts. Soft white rubber "P" strip or other rubber can be used to seal the plug to hat interface at closure. I will just list the operational problems I had to overcome and the fixes. If you have a slider and decide to do this it may help you work through the debugging process.

1 - The plug gets to move freely and will slide off of the rail upon opening and it will get torn up upon closure. Fix - Built up a a slight silicon drag bump on the last rail screw head to decelerate the plug upon opening.
2 - The pins pull out. Fix - Extend the pins all the way through the plug bend them back and pull the bent back ends into the plug to give a mechanical connection.
3 - The string sags into the bent down area of the rear fuselage skin and eventually gets cut. Fix - Put plastic tubing on the string to prevent its falling into the wearing/cutting features of the assembly - push the tubing all the way over the eyes of the pins.
4 - If one piece of string comes untied, cut or broken the whole pull system fails. Fix - Tie the doubled pull strings to each eye with a slip knot secured with a square knot. Then tie individual loops on the end of each pull string partially remove the plastic glide block bolt and slip all four loops over it and reinstall.

Our cockpit is pretty air tight with all of the other sliding canopy seal devices written up in the RVator not too long ago. One thing to remember if you read that article; it leads you to believe that the seal on the 3/16' side skirt ribs I developed is achieved between the rubber glued to the bottom and the canopy deck - that is not true at all. The rubber extends past the edge of the ribs and seals against the edge of the slider roller extrusions which are parallel to the rib edges.

As you may sense you can go to a lot of trouble to eliminate the leaks and some of them require a lot of detail work and rigging care & patience. BUT - it can be done.

Bob Axsom
 
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re air leak

yes it is a slider. thanks for the information, i'll start looking at the canopy. that cold croch has gotta go.

danny
rv-6
423sh
 
Cold Crotch is more specific

The cold crotch is due to leaks under the seat pan coming up through the boot. Working the canopy leaks won't help that condition. Ours went away with the aileron pushrod boots and sealing all the openings down there. If you didn't use ripstop nylon for your boots they may still be leaking.

Bob Axsom
 
One more thing to try

I ask my wife at breakfast if she still feels any cold air coming up through the stick boot. She said there is still a little bit but nothing to complain about like it was before I put the boots in (we used to have to wrap a towel around the stick for her to endure a winter flight). There is one more under seat air path that I have done nothing about - the one from the rear of the plane through the elevator pushrod tunnel under the bagage floor and the seat pan. You might try a boot on the elevator pushrod somewhere along its routing through the bulkheads if the sealing I talked about earlier doesn't do the trick for you.

Bob Axsom
 
air leak

bob,
what is ripstop nylon? i used a vinel material. helped a lot but it seems like it comming from the sides where the seat pan meets the side of the fuse.

dan
 
It is a special nylon

It is the material Ken Scott used and wrote up in the RVator a year or so ago. I used it arter reading his article and it did a very good job. I went to a fabric store here in Fayetteville Arkansas and they had plenty of it in stock. I'm sorry I can't give you technical details - I just don't have any. Ken in his writeup uses his normal colorful writing style to make the point that it is exceptionally good for the porpose. I looked for the article but I haven't been able to find it yet. Have to eat dinner now but if someone else doesn't come up with the description I will continue searching tonight.

Bob Axsom
 
Control tube pass thru

I think someone mentioned it and you can make it or buy a kit already made (forgot who makes it, someone can chime in).

The Nylon folks are talking to is just plain old cheap heavy duty rain coat material, any fabric store can sell you. You make a boot (like a stick shift boot) by making a "cone" out of the nylon. A large paint strainer is a good pattern. The pointy end of the cone has a hole to allow the control tube to penetrate or pass thru and held in place with nylon tie wrap. The base or wide end of the cone is attached to the side of the body rib with some aluminum strips and pop rivets or screws and nut plates if you want. Good Luck. George
 
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I found the article

It wasn't in the RVator at all, it is in the October 2003 issue of Sport Aviation. I described my version of the installation in detail with photographs in an article that is available on line at http://www.eaa732.org. Click on "newsletters" then click on the March 2005 issue PDF or HTML version. I used sheet metal screws instead of pop rivets reasoning that I may have to remove them someday. If you do this besure to remove the wing to fuselage closure strip and put RTV on the pointed ends of the screws where the extend into this area. You will notice that the mounting surface for the mounting rings is not a flat plane so some sealer (I used red RTV because I had some) is required. The material is generally as described by GMCjetpilot and Sprucemoose and it is available at regular fabric shops by the name ripstop nylon.

Don't forget to seal all of the sidewall penetrations - wing spar to fuselage, etc.

Bob Axsom
 
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Another material

Guys,

Another material you can use is a genuine chamois from the auto store.
It's really soft and flexible, and contact cements well.

I've had some in use on my sailplane (same location - wing push rod boots) for 15+ years and they are still OK.

gil in Tucson
 
re air leak

to all thanks for the information. if found a 5/8" round backer rod made by md specialty.(in the hardware store) it's the same foam as the pipe insulation but it's a solid round foam tube. cut it to lenght fit perfectly into the skirt where the gap is and what a diffrence. it's about 25 degrees here today in ny and flying with a sweat shirt i had to lower the heat.

thanks guys
danny
rv-6
423sh
 
Wrong e-mail adr?

Hi fellow builders.

Merry Christmas to all of you!

I want to buy the aileron bushrod boots from Flightline Interiors and I sent them an e-mail a couple of weeks ago. It was bounced back however, saying that the e-mail adr I used was wrong.

I used the one on their website: [email protected]

Does anyone have another e-adr to them which might be working?

Best regards Alf Olav Frog / Norway
 
air leak

i had the same problem. it comes from the space on the slider canopy. bought some 1/2 inch round foam battern from the local hardware store pushed it in between the canopy and fus side. 99.99 better.

regards
danny
 
Seasonal Caulk

I have just finished installing boots in my RV9A and haven't flown the plane yet to tell how well they work. Prior to installing the boots, I needed something to tide me over for a trip I took about a month ago. I got into the cockpit with a caulking gun and a tube of one of my favorite products, "Seasonal Caulk" and sealed all the openings in the floor pans and such. I sealed around the seat belt anchors, around the spar panel and a number of small openings. It really helped. A few weeks later, when I started the job of installing the boots, all the caulk strips came off like unzipping a zipper. I really like that suff for things like airplanes that have to come apart every so often.

Good Luck
 
Everyone has given you very good advice ... here's my 2 cents.


Remove the wing root fairings and caulk the main spar ... we found ALOT of air leaking around the wing spar. Also on the inside caulk around the top of the main spar along the 45deg brace and outer wall.

Also add foam to the ribbed spaces on the bagage wall.

Add seat heaters, they help alot in northern states.
 
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