effects and what looks like part of a food cart. >> translator: we retrieved during our one-week operation several objects which were mostly parts of the airasia plane. >> reporter: the main body of the plane and the critical flight recorders still on the sea floor. 16-foot waves and muddy conditions under water mean zero visibility. more than 50 vessels and helicopters an more than 80 deep divers are dedicated to the search. china has sent experts and portable sonar equipment. the "uss sampson" is helping recover debris while the "uss fort worth" deployed sonar equipment. >> we can find things on the sea floor as small as a golf ball. >> reporter: while the investigation into what caused the crash is under way, another investigation is taking form. should aviation authorities have allowed flight 8501 to take off despite massive thunderstorms?