If you're seated wear your seat belt! Incidentally, reports that the airplane dropped 1800 meters or about 6,000ft are incorrect. The loss of altitude was likely a descent to find smoother air. I recall flying in formation back in my USAF days with bad turbulence and aircraft only deviated 10 or 20 feet from their altitude. How big does a speed bump need to be to cause damaging accelerations at 575 mph? Happy landings