As in other parts of life, in flying we count on numbers, infinite streams of digits, or more to the point these days, ones and zeroes, describing what we do in the physical world, and in the operational one, too. With due deference to poets and screenwriters, aerodynamicists explain how we fly not in terms of wonder and joy, but by using math. Numbers define our airfoils and rotation speeds, our winds aloft and ILS minimums, our fuel burn and estimated time enroute. Numbers rule, and rule absolutely if we look deeply enough. If rotation speed varies from takeoff to takeoff, it’s not because the math changes, but because there are other variables—temperature, runway surface, tire inflation or bugs on the leading edge—to be taken into account or, if lacking…
