Countersunk counterbalance pipe per plans. Attached nose ribs to the counterbalance with blind rivets. Clecoed the leading edge skin to counterbalance/rib assembly and riveted nose ribs to spar. Clecoed aft skin and riveted the leading edge skins and trailing edge skins to the top of spar. Inserted main ribs and riveted them in place per plans. Installed the 406 and 407 brackets.
