The onerous but necessary task of computing the weight and balance before a flight is now easier with Sporty's Weight and Balance Kit. Place an aluminum plotter over a diagram of the airplane's weight and balance envelope and draw a line for each payload element. The result is a series of connected lines on the diagram; the point where the line ends is the airplane's total weight and center of gravity. If the end of the line is within the envelope, you're good to go. The kit includes an aluminum plotter engraved with the airplane's N-number, a reusable laminated graph and instructions. The kit for piston singles weighing less than 3,000 pounds is $50; it is $55 for piston singles weighing more than 3,000 pounds; for piston twins weighing less than 6,000 pounds, the cost is $65; and for piston twins weighing more than 6,000 pounds, the price is $70. To order or for more information, call 800/543-8633 or 513/735-9000; www.sportys.com.