Abstract: Ultraviolet light curing of a composition on a unit such as an aircraft canopy includes an ultraviolet light generator mounted for movement in at least three directions of motion relative to the unit. The generator is selectively movable in relation to the unit according to prerequisite procedure. A regulated environment cell is provided for the curing. The ultraviolet generator follows predetermined sequences and can be located partly within the canopy during curing. The canopy, after being mounted on a mobile fixture in the horizontal position is pivotally turned to be vertically located strategically relative to the ultraviolet light source during curing.