The performance of multiple downcomer fractional distillation trays is improved by intercepting the liquid egressing from the bottom of the downcomers in a manner which directs a portion of the liquid along the major axis of decking of the next lower tray. This is accomplished by the use of improved antipenetration pans suspended below the downcomers of the upper tray. The antipenetration pans have extensions running parallel to the decking areas of the next lower tray. A portion of the liquid falling from the upper downcomer flows to the end of the extensions, where it falls onto the lower decking at more distant points than with prior art antipenetration pans.