The China Eastern Airlines Corp. jet that crashed Monday was traveling at close to the speed of sound in the moments before it slammed into a hillside, according to a Bloomberg News review of flight-track data.
Such an impact may complicate the task for investigators because it can obliterate evidence and, in rare cases, damage a plane’s data and voice recorders that are designed to withstand most crashes.
The Boeing Co. 737-800 was knifing through the air at more than 640 miles (966 kilometers) per hour, and at times may have exceeded 700 mph, according to data from Flightradar24, a website that tracks planes.
“The preliminary data indicate it was near the speed of sound,” said John Hansman, a Massachusetts Institute of Technology astronautics and aeronautics professor who reviewed Bloomberg’s calculation of the jet’s speed. “It was coming down steep.”
Sound travels at 761 mph at sea level but slows with altitude as air temperature goes down and is about 663 mph at 35,000 feet (10,668 meters).
Flight 5735 was flying to Guangzhou from Kunming with 132 people on board at an altitude of about 29,000 feet when it began a sudden descent, according to data transmitted by the plane and captured by Flightradar24. The jetliner was cruising at about 595 mph before the dive.
The speed data is consistent with videos appearing to show the jet diving at a steep angle in the moments before impact and indicates that it likely hit the ground with huge force.
“It was an exceedingly high-energy crash,” said Bob Mann, president of R.W. Mann & Co. consultancy, who did not participate in the speed analysis. “It looks like it literally evaporated into a crater. Do the flight data recorder or cockpit voice recorder or quick access recorder — do any…
Source : time
