Wing Cover using PK Screws

[jim34285]

Is there someone who has gone this route?

If so, would you do it again?
Were there problems?

[mikeg]

Re: Wing Cover using PK Screws

Is there someone who has gone this route?

If so, would you do it again?
Were there problems?

Yes and Yes. There is an STC for the stamped rib wings.
Mike

[murphy]

Re: Wing Cover using PK Screws

How about fabric rivets, anyone use them? Thanks, Mike

[Hank Jarrett]

Re: Wing Cover using PK Screws

I haven't used them, but I watched a guy trying to remove them. I guess there is supposed to be a tool that keeps the rivet from spinning in the hole but he didn't have it if there is. I heard words I hadn't heard since I was in the Navy. When I left he had done a LOT of drilling for very few rivets removed. I didn't want to stay and watch him have a total breakdown.
Hank

Guess you can tell I wouldn't go near them. I LIKE the Taylorcraft wires.

[VictorBravo]

Re: Wing Cover using PK Screws

Here's something P-K'ish to try instead of the wires... Stamped ribs only...

Use a dimpling die set or one of those bench mounted dimpler/riveters that the RV builders are all using. Dimple the holes to a 100 degree angle. You can do this with a squeezer by hand,or do it on a bench before the ribs are put on the spars.

Put on the fabric. Poke holes in the fabric with the tip of a soldering iron for a tear-proof hole.

Insert the correct 100 degree PK sheet metal screw through a TINNERMAN flush countersunk washer, then screw the assembly through the fabric and into the rib. The Tinnerman washer applies a far greater area clamping force on the fabric (larger area), and the flush head screw/washer combination is raised only a few thousandths above the fabric contour.

Put the tapes over the ribs and finish normally. This would be the lowest profile installation possible, AND the strongest because of the best clamping force. AND it is easy to remove/replace with no grief or drilling. AND relatively cheap. AND the prettiest/least drag!

[Hank Jarrett]

Re: Wing Cover using PK Screws

Bill,
I agree with all you said. Simple, strong, safe, easy to remove later, better in every way than the approved method.
Aw C**P! There is that dirty word, "approved"! If the FAA finds this method on a certified plane you are TOAST.
I really like the idea and think the next step is some tests to prove it works as well as it obviously will with a "Fed" looking over our shoulder for an STC. Anybody know how to do the STC process? (;f
Sounds like a good "group project".

Hank

[mikeg]

Re: Wing Cover using PK Screws

Bill,
I agree with all you said. Simple, strong, safe, easy to remove later, better in every way than the approved method.
Aw C**P! There is that dirty word, "approved"! If the FAA finds this method on a certified plane you are TOAST.
I really like the idea and think the next step is some tests to prove it works as well as it obviously will with a "Fed" looking over our shoulder for an STC. Anybody know how to do the STC process? (;f
Sounds like a good "group project".

Hank

All,
I did the STC once about 15 years ago on a 1945 BC12-D that I restored. As I remember you put the fabric on, shrink it up, install reinforcing tape over the rib capstrips, drill 1/16" holes in the rib caps between the wire holes, install No.4 X 1/4" truss head PK screws and fabric washers (ala Champ) and cover with 2 inch surface tape. Basically, just like a 7AC Champ. Really simple and quick. Looks good too. BTW, if you like aviation history, my 1929 Model 2 Fleet also has PK screws attaching the fabric on everything but the ailerons and that was from the factory. Not much new in aviation.
MERRY CHRISTMAS
Mike

[Hank Jarrett]

Re: Wing Cover using PK Screws

You don't know where the STC is now do you? You wouldn't maybe have a copy laying around would you? It would be really great if one of the tribe wanted to get the STC back in use. Always easier if you can show "the man" it has already been done, especially when the first time plane has been flying around for years (or decades) with no problems.
What was the number of the plane you did it on? Maybe we can find it and see how your work stood the test of time.
Hank

[mikeg]

Re: Wing Cover using PK Screws

You don't know where the STC is now do you? You wouldn't maybe have a copy laying around would you? It would be really great if one of the tribe wanted to get the STC back in use. Always easier if you can show "the man" it has already been done, especially when the first time plane has been flying around for years (or decades) with no problems.
What was the number of the plane you did it on? Maybe we can find it and see how your work stood the test of time.
Hank

Hank,
Should be able to come up with the STC number, if I can get my brain engaged and remember what I remember.
Merry Christmas
Mike

[mikeg]

Re: Wing Cover using PK Screws

Hank,
Should be able to come up with the STC number, if I can get my brain engaged and remember what I remember.
Merry Christmas
Mike

Hank,
Got lucky and found it right away. This is from a list of Taylorcraft STCs down loaded from an ATP (Aircraft Technical Publishers) data base in 1998 (dad gum time sure gets away from you). Anyway, to the point.

STC for Taylorcraft models: BC with metal stamped ribs

STC holder: Capital Air Services; P.O. Box 467; Dover, Deleware, 19901

STC No. SA1-217

I did talk to the gentlemen back in the day and he did say he had done a number of them and sold quite a few of the STCs in the '50s and '60s. Procedure was much like a Champ, Ercoupe, or Fleet (these are what I have done, there may be more). I would start by trying to run the guy down by phone (that is what I did exept it was 20 years ago or so). Failing that you might talk to the FAA and see if you can get a copy. Mine went with the airplane (don't remember the N number and can't find my copy of the 337. I will talk to my FAA PMI after the first of the year and see what luck I have. Somebody on the tribe should have some luck tracking this down.
Merry Christmas,
Mike

[astjp2]

Re: Wing Cover using PK Screws

I just got the 337 for rib stitching approved for the stamped ribs, no more holes. Tim

[N96337]

Re: Wing Cover using PK Screws

I've used rivets and screws on planes other than Tcrafts, and of the two, I'm much fonder of screws. Use slotted heads, not cross, and when it's time to remove them , you can take a Dremel tool with a fine cutting wheel, to re-cut the slot if necessary. A small container of valve grinding compound is handy to have to dip your screw driver tip into when removing the screws.
The rivets are a bit hard on the ribs in my opinion, and they can be a bugger to remove if you don't get them drilled right. Both are better than the wire in my opinion.
I have to admit, I'm with Tim on the stitching. I've done a couple that way and it's by far the most satisfactory to me. My FSDO here says it's a no brainer, and they didn't require any paperwork. I just layed some anti-chafe tape on the rib edges and went to work...looks great, and lasts a long time. I plan on doing that with mine when the wings get covered again. It's been debated on here a bunch as to the paperwork etc, but they say AC43 is pretty tough to argue with, and if it's referenced in the 337 for the coveing, all is well. Your results with your local FAA may be a bit different.
JH

[Pearson]

Re: Wing Cover using PK Screws

A copy of the stc to use PK screws is on the Taylorcraft website. There is also a letter from a FSDO saying that it views the use of pop rivets as the same as PK screws.

I have used both the screws and rivets to attach fabric. I first thought the PK screws would be overly time consuming, but after you get the knack of it, it goes almost as fast as the pop rivets.

I have also removed the pop rivets. The only tool I used was a pair of needle nose pliers and a 1/8" drill. I used the pliers to hold the head of the rivet to the rib while drilling.

When I do the wings of my project plane, I think I will use the screws. Squeezing that pop rivet gun gets pretty tiresome. And I am too cheap to buy the air powered one.

[astjp2]

Re: Wing Cover using PK Screws

Why not rib stitch? then there can be no damage to the ribs? Tim

A copy of the stc to use PK screws is on the Taylorcraft website. There is also a letter from a FSDO saying that it views the use of pop rivets as the same as PK screws.

I have used both the screws and rivets to attach fabric. I first thought the PK screws would be overly time consuming, but after you get the knack of it, it goes almost as fast as the pop rivets.

I have also removed the pop rivets. The only tool I used was a pair of needle nose pliers and a 1/8" drill. I used the pliers to hold the head of the rivet to the rib while drilling.

When I do the wings of my project plane, I think I will use the screws. Squeezing that pop rivet gun gets pretty tiresome. And I am too cheap to buy the air powered one.

[Pearson]

Re: Wing Cover using PK Screws

Rib stitching the stamped ribs has been discussed on this forum before. Some say the edge of the rib will cut the stitching. Others say, just put something on the sharp edge and go to it.

I personally hate rib stitching. Not the product, the process. I find it very tedious. I think the screws or pop rivets are much faster, and if done properly don't make as big of a lump under the fabric as the knot in rib stitching. Personally, I like the PK screws! But that is not to say that you can't use rib stitching. I just don't have the patience for it.