FIBERGLAS BUTT RIBS

[EDMO 1078]

THEY SAY, That the only stupid question is the one you failed to ask:

Well, here is one that may sound stupid, but I really need an answer.

I have the fiberglas butt ribs for the magnum, and want to use them. I also have the Magnum manual, but I cannot tell from the manual if the U-side, guess you could say the open side, of the butt ribs goes toward the wing, or toward the fuselage.

Can anyone help on this?

Also, Piper has a special rubber seal that goes between the butt ribs and the root ribs on the wing: Like any "certified part", it is costly. Is there any way to seal the Kitfox / Avid root ribs to the butt ribs? I think that the skylight overlapping the root ribs could cause abrasion on the fabric.

Thanks again,

ED in MO

Edited 1 May 2012 by Ed In Missouri

[dholly 718]

Ed-

IMHO, the cap strip on the butt rib should be towards the cabin. If you set them the other way, you will not have much sky light left to drill thru when attaching the sky light to the capstrips. Best to have those holes and rivets or screws as far from the edge as possible. I would not worry too much about fabric abrasion, just put your wings on with root ribs in place and take the covering thickness into consideration (ie., covered or bare butt ribs) when marking your butt rib position. After 500+ hours, you can see the only rubbing issues I had on my KF3 was with the turtle deck.

[EDMO 1078]

Ed-

IMHO, the cap strip on the butt rib should be towards the cabin. If you set them the other way, you will not have much sky light left to drill thru when attaching the sky light to the capstrips. Best to have those holes and rivets or screws as far from the edge as possible. I would not worry too much about fabric abrasion, just put your wings on with root ribs in place and take the covering thickness into consideration (ie., covered or bare butt ribs) when marking your butt rib position. After 500+ hours, you can see the only rubbing issues I had on my KF3 was with the turtle deck.

Thanks for the great photos Doug. Looks like your skylight overlaps by 1/4 to 1/2 inch over the wings. I did not understand that.

Ed in MO