I fabricated the cowl flap out of .040 2024-T3. As configured, the outlet area will be 60 sq in with the cowl flap up, and 120 sq in with the cowl flap down, which provides a 20% margin on the 100 sq in recommended by Avipro. The hinge is 6.5 inches of stainless piano hinge. I'll have to make the torque tube and control linkage, but I'll need some more materials.
