I love a good conspiracy theory as much as the next person (Smoking Bananas) although I really hate being forced to pay the expenses incurred by some of the more gullible among us (Global Warming). Whenever you're faced with a mystery, especially one that gets more convoluted by the minute, stop and consider if there isn't a really simple solution that explains the whole thing without involving the CIA or aliens from another planet.
Here's a simple explanation for the disappearance of MA 370 which everyone is looking for and everyone has a (conflicting) theory as to what happened. A fire on the aircraft would set the stage for everything that happened that we know about. It also points to areas to search for the plane, in this case 4 hours flying time SW of Kuala Lumpur, near Antarctica.