Brief Description: Cleco/match drill F-970 skins; firewall set in pla
Made the other F-970 conical bend. Radiused the clamping angle even more this time--no crack! Used the nibblers, then files, sandpaper, and Scotchbrite to make the cutouts in the F-623 corner ribs for the external steps. Clecoed the skin to the fuse side.
Drilled longerons to the skins from the tail fwd, up to F-904. Drilled all F-970 skins to underlying structure up to F-904 too. Checked the fit of the longerons to the top edge of F-970 skins and verified the skins extended 3/4" past the longeron fwd ends. Drilled the longerons to F-970 fwd of F-904. Fabricated the F-904L attach strips and clecoed into place.
Drew a center line on the outside of the bottom firewall flange and slipped the firewall into place, nestling the WD-602s in the inside corners of the longerons. Clecoed fwd bottom skin F-972 in place and set the blue center line on the 2nd rivet row aft of the fwd edge of F-972. Inserted AD4-4 rivets into the first seven F-970-longeron holes aft of the firewall. The short rivets don't interfere with the weldment and assure the firewall isn't causing sag. I put a piece of masking tape over the rivets to keep them in place until the WD-602s are match drilled to the longerons and F-970 skins.