Cart Shopping Cart My Store Account Orders Downloads Shopping Cart Remove item Thumbnail image Product Price Quantity Subtotal × 22. Preliminary Design Equations for Aircraft Weight Estimation $20.00 22. Preliminary Design Equations for Aircraft Weight Estimation quantity $20.00 × 13. Will Accessories Impede Our Payload? $20.00 13. Will Accessories Impede Our Payload? quantity $20.00 × 2. Airplane Weight and Balance Control $20.00 2. Airplane Weight and Balance Control quantity $20.00 × 12. Weight Control - Aircraft Design Problem $20.00 12. Weight Control - Aircraft Design Problem quantity $20.00 Coupon: Apply coupon Update cart Available coupons (Click to apply). Cart totals Subtotal $80.00 Tax $0.00 Total $80.00 Proceed to checkout