Cg Envelope News Today

Caused accidents before, when it has rotateded with the nose up, it is moved aft. >> reporter: cargo is chained down, but if one of the chain attachments fails, it could shift. >> we dont know that that happened here. that has happened in prior accidents. then the airplane becomes uncontrollable. >> reporter: chris lawrence, cnn, washington. >> joining me now is john nance, good to have you on the program. sorry under these circumstances. ive never seen anything like this. its everybodys nightma...