Normal gross weight G, weight of fuel and oil Gf+0 and necessary horsepower Nz or thrust Tz can readily be calculated by equations (4), (5), (6) or (10), (11), (12) respectively for propeller planes or jet planes, as the function of payload A, design load factor snA, range R and maximum velocity Vz at attitude z. The values of statistical constants ai, bi and numerical example are shown in appendices.
