|
|
|
|
After setting the fuselage into a level position, I hung a series of plumb lines from the upper wing leading edge. The leading edge is supposed to be straight, so eventually all these lines will have to line up. The plumb bobs hang down into the red cups on the floor which contain ordinary motor oil. (which my friend Mary calls "Plum juice"). The oil dampens the oscillation of the plumb bobs so that they don't sway back and forth
