The head of the National Transportation Safety Board says it's not unusual that the EgyptAir flight recorders have not yet been recovered.
James Hall points to the 1996 ValuJet crash in the Florida Everglades, when it took 13 days to locate one recorder in six feet of water.
EgyptAir Flight 990 crashed off the Massachusetts coast more than a week ago. Today, a tougher, nimbler underwater robot was lowered into the sea to find the flight recorders.
Searchers hope the robot, called the "Magnum," will have better luck in recovering the recorders than did another robot, the
The Magnum has a seven-jointed titanium arm that can be manipulated from its civilian ship to grasp the recorders. It also has a cage that protects it from the heavy seas.