configuration for use as a flap, to slow the plane done that lead you down the road to something nefarious. was somebody trying to fly the plane in as slowly and gently as possible. >> why would somebody try to do that? >> well, these -- as i have said frequently there is no black box for the human mind. why would somebody potentially, this is one of the theories that are out there, many theories, very few of which can be discounted. one of the theories was that a person on board the aircraft, either a member of the crew or some other individual, wanted this plane to disappear the if you wanted it to go into the ocean, in such a way that it didn't generate a lot of debris, slow it down as much as possible. >> there have been so many theories what could have happened. mechanical failure, rapid decompression, pilot suicide. does the piece of debris if determined from the plane what