A drag count is a single unit of drag as defined by aerospace engineers. Drag is generally computed using the equation:
Where:
- is the air density
- is the current airspeed
- is the drag coefficient (a dimensionless constant, usually on the order of 0.02 to 0.04 for an aircraft in cruise)
- is the aircraft wing area
A drag count of 1 is equal to of 0.0001. So if, for example, the steady state drag coefficient is 0.0200 and someone sticks a hand out the window adding 5 drag counts, the new drag coefficient would be:
- 0.0200 + 0.0005 = 0.0205 or 205 drag counts.
Drag count is used as a crude measure for the change in drag coefficient (it is not a direct measure of drag as it is associated with a reference area, it is only valid for use as a relative assessment of change).
Famous quotes containing the words drag and/or count:
“Error is acceptable as long as we are young; but one must not drag it along into old age.”
—Johann Wolfgang Von Goethe (1749–1832)
“It may be well to remember that the highest level of moral aspiration recorded in history was reached by a few ancient Jews—Micah, Isaiah, and the rest—who took no count whatever of what might not happen to them after death. It is not obvious to me why the same point should not by and by be reached by the Gentiles.”
—Thomas Henry Huxley (1825–95)