Drilling and countersinking the upper right hand wing spar to accept the nutplates onto which the furel tanks will be attached.
This was a slow and cautious job to ensure that the countersinking was done correctly, using a sacrificial aluminium angle under the spar flange to avoid chatter of the countersink bit. Once all screw holes had been countersunk, each hole has 2 associated rivet holes to attach the corresponding nuptplate, so in total three were a lot of holes to be prepared.
Finally all nutplates were riveted on using the "no holes" squeezer yoke, and everythibng is now set up to (hopefully) do the lower spar nutplates rather faster, followed by a repeat the LH spar.
Side grip clecos before location hole clecos removed
Underside view
Afte countersinking; sacrificial plate still in place
