I match drilled the reinforcement ring to the ribs using the ring as a guide. I then deburred all the holes and dimpled the relevant rivet holes in the rib. I coutersunk the rivet holes on the re-inforcement ring appropriately to accept the dimple on the rib. I then rivetted the platenuts and the reinforcement ring to the rib.
Match drilled all holes using reinforcement ring as a guide
Rivet holes dimpled reay for riveting of nutplates