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Elevator control tube boot ??

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Pilottonny

Well Known Member
Anybody done this?

When I First started flying I noticed that when I close the vents, air comes from the back. I thought this was coming from the flap-rod-holes. So I checked it with the baggage side panels removed and found a lot of air coming through the triangular openings in the rear baggage bulkhead. OK, that is easy to seal!

So now I have sealed that, yesterday a cold day, I feel the air coming out between the seats from the openings under the flap motor box.
I think that I am just moving the problem around! If I close the openings in that area, the cold air will probably turn up coming out of the stick boots area.

So what would be a good solution? Right!...., the same thing I have on the aileron control tubes!

Easy access would be at the rear F-710 bulkhead, but It will need a big ?boot? and leaves 4 big holes to be sealed on the aft deck and rear F-709 bulkhead.

Maybe better the hole in the F-706B rear fuselage bulkhead? Or the hole in the F-705A rear spar attach bulkhead?

Has anybody done this? It will not be easy on a finished plane, I guess?

Regards, Tonny.
 
Aileron Boots

I've got exactly the same cold air problem with my -9A. Air coming from the back and even up through the seat belt openings. Classic Aero Designs, who made my interior, has boots for the aileron control tubes at the wing root. I do have their stick boots and had cold air around the sticks until I installed them. I'm wondering if anyone has installed the aileron boots and if that takes care of the rest of the cold air problem.
 
I have the aileron pushrod boots, and they certainly cut down on any air coming from the wing. I don't know of anyone who has put a boot on the elevator, but if the air is coming from there, a boot should help.

I also can feel some air coming from the back, but think that it is getting picked up through the canopy-skin joint (I have a TU) which I haven't gotten around to sealing with RTV or similar.

greg
 
I thought I would still get cold air around the sticks, because I did not seal around the wing spar. I do have the aileron pushrod though and at the moment do not seem to have a problem around the sticks, or up front anyway.

Best would indeed be to close off one of the holes where the elevator push tube goes through, underneath the floor, but it is pretty cramped in there (cables passing through there as well). I will have to open it up to have a look which is easiest.

Regards, Tonny.
 
Air from wings traveling to the back......?

Mark, after reading your post again, I now understand what you are saying. You did not install the aileron pushrod boots, but installed boots on the sticks, which cured your cold air around the sticks, right? And now you are wondering if that cold air is also travelling, under the floor, to the rear, coming out of the safety belt bracket openings and flap mechanism openings, correct?

Hmmmm?? I do have the aileron pushrod boots, but as I said in my last post: did not seal around the spar! I also have the CAD stick boots. I guess I need to open them in flight to see if any cold air will come out of there!

There is certainly a way in for air. I had one of the screws from the fuel level sender leaking. Well actually it was more sweating, because it was to little to run down the tank rib. But I could smell the fuel inside when I opened the canopy after it had been closed overnight.

So maybe we do need to seal around the spar and also all the small openings where cables run through, to the wings and tanks?

Regards, Tonny.
 
Elevator Pushrod Boot But for a Drawing

I have completely sealed my wing connections, aileron boots, as well as the luggage bulkhead. Each mod helped, but I still get significant cold air coming out my control sticks boots. I want a elevator pushrod boot. I called Abbey at flightline interiors, but she wanted me to send her a drawing, and I can't find one and forgot to measure stuff the last time I had the panel off. So if someone wants to send her the appropriate dimensions she will be happy to add it to her line of "boots" and us northerners can stop wearing gloves when we fly in the winter.
;)

Hans
 
Picture of elevator push rod boot...

Hello guys,

This is how I solved the problem.

ugyj_ca8_u7ftd.jpg


The weather has been terrible for the last couple of months, so I have not tested it yet, but this (allong with sealing all the litle holes in the baggage bulckhead) should cure any cold air coming in from the rear.

Thread closed.............

Regards, Tonny.
 
A question that I have is, if you seal up all the places that the cold air is coming in how will get cold air in the summer to come in the vents? It needs to exit somewhere.
 
I have not tested this set up yet, maybe I need to make a dedicated exit-opening somewhere. I don't thnink so though, because I am not sealing area's where air wants to exit anyway (like the rear of the slider canopy, for example).

Regards, Tonny.
 
All that air that is coming into the cockpit is exiting somewhere. Find and eliminate the exit and no air will enter.

Hint - seal the side skirt to canopy deck gap and you'll eliminate most of the draft. A piece of pipe insulation, split to give two "C" sections will do the job. Cut the "C" sections to the length between the front canopy bow and the slider blocks. When you go flying, close the canopy and drop the pieces of foam into the slot between your canopy skirt and the canopy rail. Volia - problem solved.

Much easier than chasing a dozen different places where air gets in.
 
I thought the air would be flowing out the aleron push rod holes into the wing? The only openings in the wing are @ the rear spar, which should be a low pressure?
Don't racers seal these to reduce plume drag?
 
Still cold air coming in!

I flew the plane a few times since my last mod (elevator push-rod boot), yesterday it was around 2°C and I could still feel lots of cold air coming in. Now it is coming in through the flap push rod openings and the rear of the slider skirt. I expected air to be sucked out here, not coming in.

Somehow a lot of air is sucked out of the cabin, otherwise no air could come in

I have, more or less, sealed the side canopy skirts with foam-rubber strips, stuck on the inside of the skirt and sealing on top of the longerons. What I will try next, is taping up the front of the slider. I suspect that there is a lot of suction in that area.

If anybody has anymore suggestons, please post here.

Regards, Tonny.
 
Flew the plane again, a couple of days ago, at -1°C.

Since I only noticed the cold air coming in, when I shut the ventilation off when it was getting colder, I figuered this is a pressure issue. So I opened the heat more than just a crack (far to hot with the Vetterman mufflers) and also opened up the vents, to allow some cold air to mix with the hot and "Voila", no more cold air coming in at the back.

At the moment the temperatures are getting slightly higher, so I am not going to play around with this problem for the time being. May even leave it the way it is, if the wife is comfortable with it.

Regards, Tonny.
 
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