Question: An airplane weighing 100 kN has a span of 19.5 m and a wing loading of 1.925 k Nm-2. The wings are rather sharply tapered, having around the center of span a circulation 10% greater than that for elliptic wings of the same span and lift. Determine the downwash angle one-quarter of the span behind the center of pressure, which is located at the quarter-chord point. The air speed is 67 m/s. Assume the trailing vorticity to be completely rolled up just behind the wings.