The canopy of the ram air parachute of the present invention has cells which are trapezoidal in shape. The non-loaded ribs of the canopy are thinner than the loaded ribs. The different height ribs results in tensioning of the bottom skin and transfer of forces from the loaded rib-bottom skin junction through the bottom skin to the non-loaded rib. The non-loaded rib is then tensioned to not float up as high. Thus, the spanwise distortion of the top skin is reduced and the aerodynamics are improved.