Captioning sponsored by cbs this is the cbs evening news with scott pelley. Pelley good evening. The head of the National Transportation safety board said today that asiana flight 214 crashed because the flight crew overrelied on Automated Systems that they did not understand. In its report, the n. T. S. B. Said boeing should consider modifying the flight controls. Last july 6, flight 214 crashed at the threshold of the runway at San Francisco international. Three chinese teenagers were killed. 187 passengers were hurt. It was the only deadly crash of a passenger jet in the u. S. In the last five years. Heres transportation correspondent jeff pegues. Reporter before the plane crashed at San Francisco international airport, all three pilots in the cockpit missed important warnings. According to investigators, coming in for a landing, the plane was off target. It was traveling too low and air speed was too slow to make the runway. The pilots mistakenly believed ththe the autothrottle wou