Cart Shopping Cart My Store Account Orders Downloads Shopping Cart Remove item Thumbnail image Product Price Quantity Subtotal × 20. Wing Weight Estimating Simplified $20.00 20. Wing Weight Estimating Simplified quantity $20.00 × 33. Some Problems in the Selection of Optimum Airplane Configurations for Minimum Weight $20.00 33. Some Problems in the Selection of Optimum Airplane Configurations for Minimum Weight quantity $20.00 × 10. Calculation of Landing Gear and Hydraulic System Weights $20.00 10. Calculation of Landing Gear and Hydraulic System Weights quantity $20.00 Coupon: Apply coupon Update cart Available coupons (Click to apply). Cart totals Subtotal $60.00 Tax $0.00 Total $60.00 Proceed to checkout