1. Up-drill all holes in flap to #30, deburr and dimple if desired.
2. Rivet flap together using BSC-43 rivets in the top and bottom surfaces, and BSPS-43 rivets on hinge, and BSPS-42 rivets on front face. DO NOT RIVET DRIVE RIB IN PLACE UNTIL FLAP HAS BEEN TRIMMED TO LENGTH.
3. Repeat for right side flap.
