It has to do with the gross weight of the plane, as specified by others above. Swissair was a MD-11. All of the commercial aircraft crossing the Atlantic these days are considered "Heavy" aircraft, because of the gross weight. The only airline that I know that does not fly a "heavy" is Iceland Air.

Also, you will here some controllers warn of wake turbulence on the ground when a smaller plane taxis onto the runway after a jet had begun it's roll. That is more so the impact of the unexpected jet blast on a plane.