43-13--bolts & rivets

[pmanton]

I'm working on an aluminum skinned wing with a built up spar. I have discovered some broken rivets on the web of the spar near the wing root. There is no sign of corrosion or wrinkling caused by over stress, just the rivet heads were missing. The rivets were still fast in the holes. With an angle drill it was possible to drill out the rivets. (This is an older CAR3 airplane)

However setting new rivets isn't going to be as as easy without peeling the skin back.

Looking through 43-13 there are plenty of tables covering the use of bolts in repair of structures. Lots of tables about the strength of bolts and rivets etc. However I see nothing about SUBSTITUTION of bolts for rivets. Due to the fact that rivets and bolts would transfer stress differently this might be a no-no.

Yet it would be a damn sight easier to ream the holes for AN3 bolts.

How about a learned opinion on this?

Thanks

Paul
N1431A
2AZ1

[Throttle Pusher]

I would think you would have to use a close tolerance hole and bolt.
A call to your local dar should tell you if its possible or not for that location.

Ken

[P.o.P.]

One possible source is the "Cessna 100 Series Manual".

It specifies using Close Tolerance Bolts with a light push fit in lieu of rivets.

I don't recall if it is location specific.

You may also want to check out "hy-lok" rivets.

Similar to a bolt & nut the pin end with accept a hex drive.

Tighten till nut "drive" shears off.

[Gilbert Pierce]

Looking through 43-13 there are plenty of tables covering the use of bolts in repair of structures. Lots of tables about the strength of bolts and rivets etc. However I see nothing about SUBSTITUTION of bolts for rivets. Due to the fact that rivets and bolts would transfer stress differently this might be a no-no.

Yet it would be a damn sight easier to ream the holes for AN3 bolts.

AC43.13-1b Change 2 September 27,2001. Look at the tables 4-9, 4-10, 4-11. The column on the extreme right hand side gives you the number of bolts per inch necessary to replace the rivets in the left hand columns based on material thickness and rivet size. Those lines with - - means you cannot sub a bolt for those size rivets with the given sheet thickness; mostly thin sheets. The bolt substitution of all three tables are for AN3 bolts.