A fluidizing outlet is provided having plenum sheets which define with the sides of the bottom pan of the outlet a plenum chamber. At least a portion of the lower edges of the plenum sheets are spaced from the sides of the bottom pan a suitable distance to provide gaps which form first fluidizing openings. Openings are provided in the upper portion of the plenum sheets to provide second fluidizing openings to fluidize the lading. The respective sizes of the first and second fluidizing openings are of a size sufficient to fluidize the lading, and are sufficiently large that they are not readily clogged by contaminates; for example, from dirty supply air and/or improper outlet cleaning to prevent operation of the outlet, and of a size sufficient that substantially all of the lading is removed during unloading. It has been found that the spacing between the outlet pan and the plenum sheets forming the first fluidizing openings should be at least about 0.03 inches, and should not exceed about 0.04 inches. It has further been found that the openings in the plenum sheets forming the second fluidizing openings should have a cross-sectional area of at least about 0.002 in..sup. 2, and should not exceed about 0.004 in..sup.2. The second fluidizing openings should be spaced from each other within the range 0.75 to about 1.25 inches.