If the transponder were switched off, wouldn't the plane still show up on radar? I thought the transponder just gave out information, such as make, type of aircraft, speed and altitude.
Also if the plane broke apart in mid-air wouldn't that be picked up on radar?
Another thing that baffles me is according to a sky news report they are searching a body of water 100's of miles to the west of Kuala Lumpur. I thought the plane left Kuala Lumpur and was heading north to Beijing. So why are they searching over a body of water the plane wasn't even supposed to be flying over?