How is parasitic drag calculated in relation to airspeed?

Parasitic drag is the drag experienced by an aircraft that is not associated with the lift produced. This type of drag increases with airspeed, and specifically, it is proportional to the square of the airspeed.

As the speed of the aircraft increases, both the dynamic pressure (which is related to the air density and the square of the velocity) and the effects of friction increase, which contributes to the increase in parasitic drag. This relationship is crucial for pilots to understand, as it affects fuel efficiency and flight performance at higher speeds.

For example, if an aircraft doubles its speed, the parasitic drag doesn't just double; it quadruples, necessitating careful management of speed to maintain efficiency and control during flight operations. Understanding this quadratic relationship helps pilots make informed decisions regarding speed management during various phases of flight.