Riveted R901 Skins, rudder horn and spars. The 1st and 4th rivets on the R904 lower rib were drilled to #30 and dimpled accordingly to accept a 1/8" blind rivet. It was not possible to reach the shop side with a bucking bar. The last two rivets on the top rib were drilled to #30 and dimpled to accept blind rivets iaw Drawing 7.
