ribRotationType

z turns the ribs about the normal of the chord surface, in degrees. The direction from which the angle is measured follows from ribRotationReference:

• without it, the direction of growing η on the chord surface, so that 90 degrees puts the ribs across the wing;

• the UID of a spar, or the keyword leadingEdge or trailingEdge: the direction of that line where the rib meets it, so that 90 degrees puts the ribs perpendicular to it;

• the keyword globalX or globalY: the x or the y axis of the wing, so that the ribs of the set all run in the same direction, e.g. in flight direction.

Panel (a) shows a rib of the outer set of the example: its reference is the rear spar, and z = 90 degrees puts it perpendicular to that spar. Panel (b) shows the second angle, x of the cross section (wingRibCrossSectionType), which tilts the plane of the rib against the chord surface; the value shown there is illustrative.