Attaching leading edge

MikeB · Post by **MikeB** » Mon Jul 07, 2008 08:34

I'm getting ready to attach my new leading edge from Wag Aero. Seems to fit very well on the new .032 ribs. I remember a AD or service letter regarding the number of screws needed to properly attach the leading edge. My old leading edges are no help as they have holes all over the place. Can someone point me in the right direction here? (location, size and required number of screws).

Thanks,
Mike

powers · Post by **powers** » Mon Jul 07, 2008 09:47

http://rgl.faa.gov/Regulatory_and_Guida ... hlight=7ac
Heres the AD from the FAA website. It shows you all the dimensions. Screw s are AS6-4-4. Use a #44 drill bit with them.

MikeB · Post by **MikeB** » Mon Jul 07, 2008 12:35

Thanks!! That's what I was looking for

.

Mike

powers · Post by **powers** » Mon Jul 07, 2008 14:15

While we're talking about leading edges. I didn't buy new ribs for my wings so I've got a bunch of old holes. Some of the holes are worn out and some will still take the AS6-4-4 screw. Also, they are close but not exactly where they need to be for the leading edge AD. So, I'm wondering if I should go ahead and drill new holes or make due with what I have. The main reason I hesitate is because there are already a lot of holes.

The same question stands for the fabric screw holes. Should I drill them all out or mix match them? Mix matching will be kind of difficult once I have the fabric on.

MikeB · Post by **MikeB** » Mon Jul 07, 2008 15:13

Regarding the leading edge (this is a personal opinion) I think as long as you're close you should be OK. It appears the reason for the AD is to stiffen up the nose of the ribs and leading edge. Regarding the oversize fabric holes I believe they say to move it 1/4" and redrill the hole to the correct size for the PK screw. The problem I ran into was that there were so many holes already in the ribs I just didn't want to mess with them. Of course, it's possible to repair the rib by 'flush riveting' a plate on the bottom and redrilling the hole in the original positiion but it's very time consuming.

The new ribs are now .032 instead of .020 and use pop rivets for fabric retention.

Mike

powers · Post by **powers** » Mon Jul 07, 2008 17:29

I think I might re-drill the fabric holes so that the screws look uniform. My next question is wether or not to put the little wood pieces between the top of the spar and beneath leading edge metal? My old spars had it, but I'm not sure if thats original or not.
Also, my leading edges are in four pieces. Which one goes on first? Do you put on the root and then over lap on the way to the tip or the other way around?

james gevay · Post by **james gevay** » Tue Jul 08, 2008 07:42

Mike I agree that if you can come close to the specified measurements for the holes then you are accomplishing the intent of the AD. Remember when the FAA has to publish an AD they have to come with some kind of measurements to put on paper. In this case I think that the measurements are not that critical. I think that if you try and get all the screw holes in solid material and the LE mounted solid you will be fine. But thats just my opinion.

I'm planning on drilling new holes so I can to try and line them up straighter. In some places I won't be able to do that because of all the old holes drilled willy nilly. When I had the ribs off I marked them as to where I wanted the new holes and I drilled all the ones aft of the front spar. I'm not sure how I'll drill the ones under the new LE. I may drill the new holes in the ribs first and then mount the LE and mark the holes and then drill the LE or back drill while the LE is on. Here's a picture that may help explain this better. This shows the right wing with the new ribs left bare and the old ribs in primer.
[img][img]http://i228.photobucket.com/albums/ee22 ... ebpage.jpg[/img]
[/img]
I'll have to use some of the old holes but I want to keep the holes lined up as much as possible to keep the screw head bumps straight. The new holes I drilled aft of the spar were all moved back about 3/8", by the way there are just over 900 PK screws in both wing panels.
As for the wood strips in between the ribs on the top and bottom spar faces. I would not do that because you cannot inspect the spar for cracks if they are there. These are just my opinions after trying to think things through before doing the work. Jim

MikeB · Post by **MikeB** » Tue Jul 08, 2008 08:40

Good Ideas Jim (installing the ribs over the spars and marking them)
Of course I have new ribs and am going with pop rivets per SL 85. I still haven't gotten approval yet. I'm beginning to suspect the paperwork is hung up with my AI but I can't seem to push him along to finish the job. Apparently the local FSDO sent it back to be redone. Not critical right now as I'm not close to installing fabric but I'd like to have the approved 337 in hand anyway as I'm a natural worrier when it comes to dealing with FAA approval.

Mike Berg

powers · Post by **powers** » Tue Jul 08, 2008 09:05

Ya I was looking at how I was going to drill the holes to. I decided to mark my new holes on the under side of the ribs. Then put my leading edges on and drill from the inside of the leading edge. Its kind of tight in there for a drill so I'm planning on using a dremal.

Paul Agaliotis · Post by **Paul Agaliotis** » Tue Jul 08, 2008 09:16

Go to your local tool and supply and get an extended length drill. They are about 12" in length. Get a short length of brass tube about 1/4" OD and slide over the drill for a hand hold. This will create a "bow drill" allowing you to bend the extended length drill for most of the holes. The rest can be picked up with hole finders,a 90 motor, or from the top with the bow drill.
Paul

powers · Post by **powers** » Tue Jul 08, 2008 10:07

Anybody got any experience with the one piece wing tip metal? Or even better yet got a picture of it installed! Looks like its got a lot of angles.

jkvincent · Post by **jkvincent** » Tue Jul 08, 2008 12:25

...here ya go, hope this helps, Jim

Ed Clark · Post by **Ed Clark** » Tue Jul 08, 2008 20:43

I have about 50 digital pictures taken when my 46 champs wings were rebuilt replacing the wood spars with milman spars. They show the before and after. I could burn a disk and mail it to someone for posting on this site if you all would like.

I cannot answer questions about the process though. I bought the finished product from a friend who did the work. He is a retired A&P.

Post by **joea** » Tue Jul 08, 2008 20:58

Ed,

Can you just email them or are they too large? If you can email them, please PM me (message me) and I will give you an email account that will hold something this size.

Would love to post something like this for everyone.

Thx,

Joe

MikeB · Post by **MikeB** » Tue Jul 08, 2008 22:28

Does anyone have a clue why the lower (bottom) edge of the wing tip (outboard rib in) metal doesn't match the bottom edge of the rest of the leading edge? Jim's first picture shows it and mine is the same. Seems they should match to me. I was going to make a new tip and have it line up. Maybe it doesn't make any difference (??).

Mike