If you notice in the part of the movie when they are helping people jump out of the plane, the force of the air seems very great, because at the point when Harris is hanging out of the plane and they are trying to help him back in, it appeared to be very difficult with the wind drag and all. But then later when Harris is fighting the bad guy, it does not seem to affect how he is fighting, which is at the same location as he was hanging on for dear life. Nothing shows the wind drag until he kicks the guy and hangs him, but this time he did not have trouble getting back in by himself.