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PostPosted: Tue May 24, 2005 2:36 pm
by Shannon
What's this ?

PostPosted: Tue May 24, 2005 8:05 pm
by xgary
who ate your nose ribs dude?

u putting that one together?

what you use for a clamping device?

PostPosted: Tue May 24, 2005 8:08 pm
by xgary
whois is this one ??

PostPosted: Wed May 25, 2005 2:14 pm
by rayjb60
Is that the inside of the D-cell with all the foam ribs removed?

I wonder how you will get the new ribs repositioned and glued with out unriviting the skin?


PostPosted: Wed May 25, 2005 3:41 pm
by Shannon
What's this ??

PostPosted: Wed May 25, 2005 4:40 pm
by Guest
Folks, this is what loose ribs look like...check em and fix em if necessary! Great pic of this problem area Shannon.

PostPosted: Thu May 26, 2005 5:05 am
by xgary
Shannon good points, That lazair that was a Volks filed last year had many collapsed nose ribs. I think i felt a couple stilll standing i i recall.

nose ribs are an integral part of the d-cell and should be fixed immediatly.

Your Wing be be no where near the the strength needed for safe flight with loose nose ribs.

You can fell em by gently squeezing your leading edge to fell them. They about ever 4 ".

Picture you standing on a pop can. pretty strong eh ? till you open i or dent it .

Wing can fold very easy too.

You cannot fix nose ribs properly without opening up.

PostPosted: Thu May 26, 2005 2:30 pm
by rayjb60
Generally speaking, are loose ribs a result of improper construction techniques or just the effects of time on the glue?

Most all of us have pretty old D-Cells and I'm wondering if we can expect them to become loose after the glue ages.

If this is the case, then every flying Lazair should be grounded until an inspection can be performed.....before someone gets hurt and the fine reputation and value of Lazairs go to hell in a handbasket.

The implications are very serious so I think we should all find out the best way to give our planes an inspection before the next flight.

You say gently squeezing the leading edge? Or should we be doing a tap test, where we tap a coin over the ribs to see if they sound solid or not.

We need a good method to be developed, hopefully not taking the leading edge off to check.


PostPosted: Thu May 26, 2005 2:39 pm
by rayjb60
I have an idea!

You say the foam ribs are on 4" centers.

My idea for a quick fix and possibly quite a good one, would be to buy cans of expanding foam, and perhaps every 3rd foam rib bay, fill that 4" bay with expanding foam.

Not sure what the properties and strength of that would be, but you can be sure that 4" wide expanded foam rib will never fall over.

What do you guys think....opinions?

The added weight is the only drawback I can see at this point....and cost, but when your life hangs in the balance, its worth it!

Any one have other ideas?


PostPosted: Thu May 26, 2005 8:24 pm
by lazair
Nose Rib Tech. Bulletin


The owner of a highly modified Lazair reported recently that several of the foam noseribs inside his D~el1 had moved out of position. This was one of the earlier kits with the .016 inch D~ell skin, (kits A192 and subsequent have a .020 inch D-cell skin) and was fitted with relatively heavy reduction units and very large propellers.

Although this is believed to be an isolated case, it is recommended that all owners check the position or their nose ribs occasionally (especially in the area or the engine nacelles). This can be done easily by tapping along the top or the D-cell (about 4 inches ahead or the main soar) and listening for the ribs. There should be a rib every 4 inches. if you should ever get an indication that two or more adjacent ribs are out or position, drill out a few rivets so that the D-cell skin may be lifted sufficiently to look inside (with the aid or a flashlight). Any displaced ribs should be repositioned and bonded in place with panel adhesive. To avoid loosening the D-cell skin, remove only as 'many rivets as necessary and use tools made from coat hangers to fish the ribs into position.

It should be noted that because of this possible problem, the use of Rotax engines on a Lazair with .016 inch leading edge skin is not recommended.