Removed fuel tank & drilled out the rivets on "U" Channels (7V11-4K) on rib-#2 to install nut-plates for faster & easier removal of fuel tank. Drilled the "U" Channels for a total of 9 (thread 8/32) nutplates, 5-on the most forward "U" & 4 on the rearward "U". Nut plate types: Two # MS21071 MK2000 miniature single lug 8/32, two MS21069 MK 1000 miniature 2-lug 8/32, five MS21047 full size 2-lug 8/32. Mistake: drilled holes for the nut plates through rib #2 drill size #40. Nut plates are only attached to the "U" channel for their removal.
