Steady level flight, so lift equals weight and thrust equals drag. Pick an aircraft and an altitude; the curves below are computed from the drag polar CD = CD,0 + KCL2. Watch what altitude does to each minimum — they do not behave the same way.
Move the pointer across the plot to read values; click to pin.
Standard atmosphere in English units, ρSL = 2.377×10⁻³ slug/ft³. Aircraft data from the AESP 420 lecture examples. Stall speeds use an assumed CL,max and are indicative only — the lecture data set does not specify one.