Method of making a perforated metal sheet

Abstract

A movable sheet overlying a wing is disclosed that creates laminar flow over its exposed surface. The movable sheet serves as an integral, retractable shield for protecting a suction support structure of a wing against contamination, and also serves as a movable, conductive substrate for deicing by means of electrical resistance or hot-gas heating. The invention includes a movable sheet that is mounted scroll-like on two motor-driven rollers. The sheet has a solid area without perforations that protects the suction support structure from contamination, and a porous area with perforations therethrough that allows boundary layer suction. The motor-driven rollers scroll the sheet to cover the suction support structure with either the solid area or the perforations of the sheet. Contact rollers at the edge of the sheet supply electrical current to resistively heat the sheet and melt any accumulated ice. The movable sheet can also be moved back and forth to dislodge the ice.

Dependencies are inferred from the claim text.