Brief Description: Drilling the Canopy Hinge Blocks to the Ribs
Make the C-617, C-618, and C-619 spacers as shown on DWG 47. Temporarily remove the F-644 ribs. Clamp the C-617 block to the F-745 rib with the aft surface of the block flush to the aft edge of the rib and the top surface of the block just low enough to clear the skin when it is installed. Drill two shallow #12 pilot holes into the block using the two pre-punched 3/16" holes in F-745 as a guide. Drill only about 1/16" deep into the block. Remove the block and finish drilling the holes in .a drill press using a #10 drill. (Be sure the drill press table is level and square). UHMW plastic tends to expand when drilling and then shrink back after the drill is removed. A #10 bit will produce a hole that will be a slip fit for an AN3 bolt. Clamp the C-617 and C-618 blocks together, with the forward and top edges flush. Use the holes in C-617 to drill C-618. While the two blocks are joined, carefully measure the location of the %" hole for the canopy hinge pivot bolt and drill it through both blocks. Repeat the procedure with the other C-617/C-618 blocks. Reinstall the C-617 blocks on the F-745 ribs with temporary bolts. Drill the %" holes in the F-745 ribs, using the holes in the C-617 as a guide. Pull a .251" reamer backwards through the block and rib a few times to get a nice slip fit on the modified AN438 pins. Drill the upper hole in the C-619 spacer to the measurements shown on DWG 47. 8e sure to maintain the bolt hole edge distance because this spacer will be used later as a guide/stop for positioning the canopy frame. Clamp the C-619 spacer to the C-617 block, insert a bolt through the hole and drill the second bolt hole. The F-644 ribs were drilled but not riveted to the F-768 bulkhead during fuselage construction. Now they must be match drilled to the block assembly. Cleco the F-644 ribs to the F-768 bulkhead. Insert the C-617/618/619 assembly between F-644 and F-745 and slide bolts through the holes until they contact the face of F-644. Clamp the ribs and blocks together, using just enou
