Wing Fabric

[Bobdog]

Hi Gang, I'm in the middle of covering my wings, and I'm working on the aileron coves. What is the proper way to cut out for the center aileron hinge? Is there suppose to be a pair holes in the fabric just large enough for the hinge and the push/pull tube, OR, is the fabric suppose to be trimmed all the way to the cut-out in cove sheet metal? Thanks, Bob

[1938BF50]

Re: Wing Fabric

Bob,

One of my wings was trimmed to just clear the bracket/hinge...the other was trimmed all the way back to the opening size of the sheetmetal. The latter promoted bird colonization. The wingtip had a couple cubic feet of grass packed in on that side. You can trim around the opening and then later place a preshrunk patch over that hole to close things up prior to silver. Dont forget an inspection "rectangle" topside on the wing in this same area. If you ever have to adjust the ailerons you will know what I am talking about. Make sure your rod ends are fairly centered before mounting them.....giving you the maximum amt of adjustment.

[Forrest Barber]

Re: Wing Fabric

From the factory it was all the way to the cut out. Not good because of birds, I close it up. Rectangular is correct, a round plate does not give a lot of room. But that is how they did the F-19's..... oh well.

[VictorBravo]

Re: Wing Fabric

For what it's worth, here's a workable suggestion.

Trim it back to the huge square opening. Finish the airplane through paint. Then put a piece of clear plastic on as a cover, with holes just large enough to allow full movement. You will be able to do a full preflight inspection, keep birds and water out, and remove it for maintenance. I'd use a fairly good double stick tape (carpet tape), the key is to find something not quite strong enough to remove the paint when you peel it off. Then for double safety, put 3M brand "Blenderm" surgical tape over the outside lap joint to keep water out.

You will have to use fairly thin Mylar or Lexan sheet, so that if it does come off in flight you will be able to overpower it with the controls (not let it jam the controls).

I believe this falls under "non-structural fairngs, wheel pants, strut cuffs, etc" under the part 43 stuff the pilot can do without an IA signature.

For what it's worth, IMHO making up flexible sheets of Mylar taped on over the gaps for the hinges is a good thing for airplanes parked outside... rainwater and snow will not get into the hinges and stuff. These sheets can be taped on the top of the wing itself, with just enough overlapping hinge openings to keep water and ice off. These will not act as control gap seals because the airflow will lift them off the surface in flight... in effect they won't do anything good or bad in the air.

3M Blenderm is one of the greatest materials an airplane tinkerer can have laying around. It is a special order tape, I got a box off of ebay, and it comes in 3 widths. The 1 inch and 2 inch are the most useful on airplanes. The difference is Blenderm stretches more than other tapes, is thin and totally air/water tight. It will not peel off without considerable effort, and the residue requires Xylene ( "Goof Off") to remove.

Taping over the elevator and rudder hinge line is also wotrhwhile IMHO, but you have to do it in a way that it does not restrict any of the movement of the controls. Move the control surface fully opposite the side you are taping and push the tape into the gap so it is not tight even at full deflection. Apply vaseline to the hinge tubes/pins only where the tape contacts the actual hinge tube (so the tape does not stick to the hinge itself). This is a job for the 2" wide Blenderm, not the 1" wide.

The gap between the stabilizer and fuselage is another candidate for tape. Makes the plane microscopically more efficient, but keeps the water off the stabilizer attach bolts.

In the sailplane world we used to do this kind of stuff for speed/drag effect. But on a T-craft it becomes cheap insurance against corrosion. Any GOOD FAA inspector will agree that protecting a steel aircraft against corrosion is more important than most of the other things. Besides, the tape is a "decorative" spiritual blessing, according to the owner's religious beliefs (Lilienthal Branch of the Worldwide Church of Bernoulli, presided over by Sister Amelia, Our Lady of Perpetual Navigation).

The tape can be removed on demand if you have a visit from representatives of the Church of Bureaucracy, WingSpan-ish Inquisition.

[Bobdog]

Re: Wing Fabric

Thanks, everyone for the help. It's really nice to know the original way it was done, a better way to do it, and an different way to do it. Bob

[Len Petterson]

Re: Wing Fabric

In the Lithental Church of Bernuli, are the Reverend of Drag Holdback supporting the opinions of the congeration of Church of Buracracy, if so he should be silents with some Blenderm tape and sent fort to the Queen of Fast Movers to account for his reacctions to King of Velocity, causing the common fast movers to increasing their support to the "King of Pitsh in the Earth" to hord more off the commoners and other citicens hard earned tradeing coins when ever the citisens deside to poor on a coal.
Dear memebers of this Abov the ground travel fraternety, lets take the caracters mentioned in this Story with a a large Graine of salt of earth.
And let the blenderm cover the rest off our sins!
Len
Blenderm is Darn Good Stuff!
I orderd it through my local pharmacy.

[mhorowit]

Re: Wing Fabric

[QUOTE=Len Petterson;24686]

Well said, Len - Mike

[mhorowit]

Re: Wing Fabric

Bob,

You can trim around the opening and then later place a preshrunk patch over that hole to close things up prior to silver. Dont forget an inspection "rectangle" topside on the wing in this same area. If you ever have to adjust the ailerons you will know what I am talking about. Make sure your rod ends are fairly centered before mounting them.....giving you the maximum amt of adjustment.

I have a fair idea of how that might be done, but I do have a question or two:

1. I assume a series of small sheetmetal screws would secure the patch to the wing. You'll have to embed something in the wing fabric and in the patch. Thin aluminum? As a matter of fact, why can't I use a piece of thin aluminum as the patch? After all, didn't we discuss aluminum sheet in place of fabric when replacing a wing tank?

2. Any concerns about moisture entering thru the edges? any gasketing? any concerns about interference with airflow?

- Happy New Year - MIke

[Robert Lees]

Re: Wing Fabric

Mike,

I did my inspection hatch like this, setting an aluminium square under a patch. I had pre-drilled the #4 screw holes:



What you can just see is that I completely covered the middle hinge/pushrod hole, and only opened it out when I had finished painting and assembled the aileron to the wing.

Rob

[mhorowit]

Re: Wing Fabric

Mike,

What you can just see is that I completely covered the middle hinge/pushrod hole, and only opened it out when I had finished painting and assembled the aileron to the wing.

Rob

Ah. First cousin to the trick with the metal around the filler in the wing tank - thanks, Mike

PS - you must be back home?? How was the US this time around? - Mike

[mhorowit]

Re: Wing Fabric

PS - you must be back home?? How was the US this time around? - Mike

Never mind; see your posting from LV. Put a nickle in a slot machine for me! - Mike