The advantage of higher strength to weight and higher stiffness to weight ratios for composite structure compared to metallic structure is well known in the aerospace industry, especially to commercial airline world. Its increased usage in the airplane structure is a direct reflection of the benefit in reduction of operating costs by lowering the fuel usage. This factor turned out to be more important for the airlines after the September 11, 2001 incident and also due to the increase in fuel prices. Besides reduction in the operating costs, airlines are seeking ways to reduce their maintenance costs. Most of the damage to the aluminum structure airplanes is attributed to corrosion. The non-metallic composite structure has an excellent property of resistance to corrosion. The structure is more damage tolerant due to the absence of fastener holes. As a result, its increased usage serves the airlines by lowering the maintenance and inspection costs.