Say that the airplane is going in 1000 km/h. On the side of the airplane, there is a 10x10 cm window. How much friction would this window cause. For the sake of the calculation, imagine that the airplane is infinitely long. The window is also perfectly level with the rest of the wall, and there is no turbulence on the side of the plane. The outside air is also standing perfectly still. The airplane is travelling at sea level.
I know it is neglectable compared to the turbulence etc. caused by the form of the airplane, but I really need the answer to the question.