the engine. >> that's a key question here. because this is a plane, this is an aircraft that you obviously have to say, assume, they had just gone through their safety checks, were taxiing in order to take off. the flight was headed to venezuela. what could happen between the safety check list time before -- those procedures, to getting on the taxi way? >> sure. it's a good question. i have flown a 767. i have many hours, very very reliable aircraft. you know, one of the crew members, either the canptain or the co-pilot, if there was a substantial leak, it certainly would have been found. or the maintenance department, they generally contract out. this particular airline probably does with maintenance folks. they would have seen it. so something happened. in answer to your question.