Cart Shopping Cart My Store Account Orders Downloads Shopping Cart Remove item Thumbnail image Product Price Quantity Subtotal × 27. The Significance of Weight Control $20.00 27. The Significance of Weight Control 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 Coupon: Apply coupon Update cart Available coupons (Click to apply). Cart totals Subtotal $60.00 Tax $0.00 Total $60.00 Proceed to checkout