Abstract:

ESDU 73019 gives methods for use in still air (ESDU 73018 gives the effect of wind) in cases when at least one parameter out of airspeed, Mach number, pressure height and engine control setting is kept constant. For each case, optimum conditions are examined and expressions for range and endurance given and provided in graphical form. For the special case of cruise-climb, expressions are given for the flight path and for corrections to range for climb gradient and acceleration. A general equation is developed for engine specific fuel consumption for use with the methods and the effect of constant engine control setting is explained. Under the assumption of a parabolic relation between lift and drag coefficients, the classical expressions for aeroplane performance at minimum drag are presented.