Airport Upgrading Versus Landing Gear Optimization

An economic analysis was performed to relate pavement upgrading cost to penalty cost associated with adding gears and wheels to aircraft to provide adequate flotation for present-day pavement design criteria. A basic assumption was made that widebody jets and 1,500,000 lb (679,500kg) aircraft (Categories I and II aircraft, respectively) would use 26 major hub airports by l985. Three gear types were designed for each aircraft: (1)Current-flotation compatible with present pavement criteria; (2) Median-compromise design considering present pavement criteria and optimal gear for aircraft structure; and (3) Optimal-gear optimized for aircraft structure with no regard for pavement flotation requirements. Costs were based on each gear type for both categories of aircraft. Rigid and flexible pavement thicknesses for each major hub aircraft were determined for Categories I and II aircraft; thicknesses were calculated both for new construction and for overlay of selected pavement areas where the aircraft might operate. Aircraft costs were developed as associated with carrying landing gear weight and volume in excess of the optimal gear. Pavement upgrading costs were determined and cost comparisons were made.