perform the miracle on the hudson. >> reporter: what we don't know is what happened in the cockpit before the plane went off radar. it could include bad weather in the area and the request to move to a different altitude. what the captain may have done with that information is still an open question. for example, whether the pilot may have tried to disregard the controller's guidance. >> what disturbs me is did he begin a climb without a clearance from air traffic control, that might be indicative of an emergency problem developing. >> reporter: there was also no known communication before it went off radar, not necessarily a radio malfunction. >> we're trained very very early on to af great, navigate and communicate being the last thing, because communicating in this particular circumstance if indeed a contributing factor was the weather, the last people that would be able to help you is air traffic control. >> reporter: the first officer