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Wing attach problems on -14A QB

jfisher

Active Member
Trying to make sure the main wing attach bolts fit the bulkhead assembly prior to mounting wings, but the bolts don't go through! Not even close. Only one of the 8 larger bolts will even go through both assemblies, and not completely. All the rest hit a hard stop after the threads go through. Smaller bolts same story. Called mother ship. They said get a micrometer to measure bolt diameters at 90 degree points and let them know.

Not sure where to go for that?

Anyone else have similar stories with wing install? Solution?
 
These are expensive close tolerance bolts. For test fitting use cheap hardware store bolts. When ready for final assembly, cold-soak the bolts in an ice bucket. If you have a space heater direct it at the spar holes for 20 minutes. Put a tiny amount of grease on the bolt shanks. Then use a rubber mallet, if needed, to drive the bolts in.
 
Trying to make sure the main wing attach bolts fit the bulkhead assembly prior to mounting wings, but the bolts don't go through! Not even close. Only one of the 8 larger bolts will even go through both assemblies, and not completely. All the rest hit a hard stop after the threads go through. Smaller bolts same story. Called mother ship. They said get a micrometer to measure bolt diameters at 90 degree points and let them know.

Not sure where to go for that?

Anyone else have similar stories with wing install? Solution?

On a set of QB wings I helped mount, two out of eight of the smaller bolt holes were not reamed all the way through the webs. This was visible by eye: at least two-three thou of the web material was peeking past the edge of the hole in the extrusion. This is a step in the instructions that was not completed at the QB assembly plant. Carefully re-ream all the holes, coming in from the extrusion side, with lubricant.

If you can't get a drill with reamer in there, one alternative would be to apply some blueing and file away at the web with a half-round fine diamond file until you just touch the extrusion.
 
It always depends on the experience level of the person you talk to at the Mother Ship.

When I called for the exact same reason on a -7 QB fuselage, they said "don't try to install the bolts before inserting the wing spars". The spar insertion helps line everything up they said.

Well they were right, my bolts slid right in when I fitted my the wings.
 
I didn't install my bolts until the wings were setup for the one and only attachment; no trial fits. I did make a pair of drift pins , and with the drift pins in place to get the basic lineup accomplished I started driving in the close tolerance bolts. All of them required some significant tapping to put in place. I used boelube on the shank and not the threads.

Put them in a ziplock bag then in the freezer, shrinks them a bit. No ziplock they can accumulate a bit of moisture with the high Louisiana humidity.

Heating the spar can help to make the holes bigger, have to be careful though because it can make the distance between the holes wider too.... Freezing the bolts has no effect on the spar.
 
Then use a rubber mallet, if needed, to drive the bolts in.

Oh, another thing: the last (aft) web the bolts go through will separate from the extrusion and break if the bolt catches it and you keep pounding on it. This is a nightmare, expensive repair. Make sure this is reamed properly and there's a clamp on it preventing the web from separating from the assembly while driving the bolt through.
 
Ditto on the recommendation to watch that thin aluminum in the sandwich. Any small clamp will do and is easy to keep out of the way.
 
Cold soak the bolts. I did this by taking a small ice chest laying the bolts flat on the bottom and covering with 90% alcohol, denatured alcohol will work too, and pack dry ice over it. I let it set a couple of days. Then take a hard wood drift, mine is oak and then drive them in with a rubber mallet. Use grease and as someone has already stated, be careful with thin aluminum web.

Regards,
 
I drove mine in with a rivet gun and brass set. Use about 25# psi and grease and they go right in. Attach wing with cheap grade 5 bolts first and drive them out with the close tolerance bolts. This was an -8. Easy.
 
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