In other words, the people didn't "fly up" and hit their heads, the plane fell on top of them.
Granted they were technically falling, too, but at a slower rate because the force that pushed the plane down - turbulence - acted directly on the plane, but the plane shielded the passengers from the direct effect of the turbulence. Thus the air did not push them down at the same rate that it pushed the plane down onto them.
Granted they were technically falling, too, but at a slower rate because the force that pushed the plane down - turbulence - acted directly on the plane, but the plane shielded the passengers from the direct effect of the turbulence. Thus the air did not push them down at the same rate that it pushed the plane down onto them.