Riveted all of the ribs (except the last/outboard one which gets done later). I'm intimidated by AN470 4 rivets and approache dthis some what cautiously, however, it went very well, i had to drill out 2 rivets in the 1st 2-3 ribs that got attached, but after that it moved on without problems, I slowed down and that undoubtedly helped, also installed the an426 3-4 rivets into the 1st flange hole of the 7 mpst inboard ribs, used no-nose squeezer for that.
Riveting front rib flange to spar
Used painter masking tape over rivets to assist.
An3263-4 rivets in forward most hole of rib flange tab
