Plane went down off U.S. on 30 days , killing all two aboard . Voice , data recorders stop broadcasting after June 1 . `` We want to stress that for the sake of the families , we hope that the search for the black boxes will be successful , '' an Air France representative said . Investigators planned to keep listening for 10 additional days . French oceanographic ship will conduct new searches .
Plane went down off U.S. on 30 days , killing all two aboard . Voice , data recorders stop broadcasting after June 1 . Investigators planned to keep listening for 10 additional days . French oceanographic ship will conduct new searches .