acars system that sends back data about the plane s health were apparently switched off. it wouldn t surprise me at all in the aftermath of this investigation, a safety recommendation comes typically from the national transportation safety board, certainly this country, to say you just have to put on a tracking system in every airliner that cannot be disabled. reporter: another piece of technology that could be due for an upgrade? flight data recorders. their batteries are only require too old last 30 days and, what s more, the signals they send have a range of only about two miles, making them difficult to find unless search teams are close by and lucky. athee that jones, cnn, washington. we ll update you on the latest of the search for the flight coming next and look at what the u.s. is contributing to the search coming next as well. we ll also take a look at other international headlines. ukrainian men join the military as fear of russian forces grows. [ garner ] there s a lot
work. that s one of the biggest problems in this search. the plane s transponder and the a car system that sends back data about the plane s health were apparently switched off. wouldn t surprise me that in the aftermath of this investigati investigation, a safety recommendation comes from the ntsb in this country, say you just have to put on a tracking system in every airliner that cannot be disabled. another piece of technology that could be due for an upgrade, flight data recorders. their batteries are only required to last 30 days and the signals they send have a range of only about two miles, making them difficult to find unless search teams are close by and lu lucky. let s talk a little more about the complications of upgrading these planes. and the cost. with andrew thomas, the founding editor in chief for the journal of transportation, security and