Cart Shopping Cart My Store Account Orders Downloads Shopping Cart Remove item Thumbnail image Product Price Quantity Subtotal × 30. The Effect of Center of Gravity on Performance $20.00 30. The Effect of Center of Gravity on Performance 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 × 25. The Effect of Overload and Unbalance on Long Range Operation $20.00 25. The Effect of Overload and Unbalance on Long Range Operation quantity $20.00 × 27. The Significance of Weight Control $20.00 27. The Significance of Weight Control quantity $20.00 × 15. Organization for Weight Control $20.00 15. Organization for Weight Control quantity $20.00 Coupon: Apply coupon Update cart Available coupons (Click to apply). Cart totals Subtotal $100.00 Tax $0.00 Total $100.00 Proceed to checkout