A Rear Channel gets installed on the spar in the gap between the two skins. At each end of the channel an L-angle is attached so task one is to cut two pieces of L-angle to the right size and mark the centre line. Then drill through the L-angle to cleco it to the channel.
Since the elevator is upside down on the bench the channel is upside down in this picture, attached to the spar. The other side of the L-angle gets clecoed to the nearby rib. I didn’t do that yet.
After this I drilled through the holes in the skin to the ribs to size 40; I will enlarge them later.
In this picture you can see that the left middle rib sticks out beyond the skin, and where the trim tab will be. So, to make room for the trim tab the excess rib needs to be removed.
Here it is reinserted in the skin. Before the trim tab can be added to the elevator, a Trim Tab Channel will be placed inside the skin, but that is for the next day.