22.214.171.124.7 Dynamic Skirt Panels
(a) The height of the dynamic skirt panel above the step tread nose line shall be at least 25 mm (1 in.) measured vertically (see Nonmandatory Appendix I, Figure I-4).
(b) The exposed surfaces of the dynamic skirt panels adjacent to the step treads shall be smooth and in one plane. Exposed edges shall be rounded or beveled.
(d) The exposed panels that comprise the dynamic skirt panel shall overlap or interlock such that no clear-through spaces exist. The distance between exposed edges of dynamic skirt panel elements shall not exceed 4 mm (0.16 in.).
(e) There shall be a positive mechanical connection between the dynamic skirt panels and the running gear.