Secure main spar to braces attached to the workbench, check wing for straight and level.
Oops ! Ok, after painstakingly checking the wing for straight and level, thinking I was ready to move ahead with installing the aileron linkages and then installing the wing skin, I will need to move clamps to the top edge of main spar, clamped to lower edge means they are in the way of clecoing the skin.
