Add to ORKGAn analysis was made at flight Mach number of 0.9 to estimate performance of nuclear-energy-powered turbojet engine and optimum engine operating conditions and to determine gross weight and load-carrying capacity of airplane powered by such an engine. The size of airplane required to carry disposable load of 20,000 pounds was found to vary from approximately 300,000 to 900,000 pounds depending on assumptions. For a reactor tube-wall mean temperature of 2500 degrees R, turbine-inlet temperature of 2000 degrees R, reactor-free-flow-area ratio of 0.33, reactor-shielding-material specific gravity of 6.0, shielding thickness of 3.0 feet, and altitude of 30,000 feet, the airplane gross weight required to carry a 20,000 payload is 545,000 pounds