apart. but that s a pretty fast rate of descent. it makes me think they had a problem, they were trying to descend, perhaps get to the airport. that s not a descent where you re falling from sky. they didn t stall, they didn t have an explosion that had blown them out of the sky. that s a descent, controlled descent. but that s a very fast descent. it s not a rate of falling. that s not a stall descent. but of course it s kind of early to tell. the radar tracings might have only picked up a certain amount of that. they could have been in that sort of a situation and the radar depart didn t get the full descent. it sounds mechanical they might have been trying to get to an airport. aviation officials, we want to turn to our correspondent