(click on graphic for larger image)Update: I made this prediction four days before any authority did.
Here is my two cent analysis of the Malaysia Airlines Flight 370 mystery. Point A on the graphic is where the transponders stopped working at cruise altitude. Point B is where the military radar last saw Flight 370, still at cruising altitude in the Straits of Mallaca, near the tiny island of Pulau Perak.
There are two possibilities at point A. The first is that the plane suffered severe mechanical malfunction that took out the transponders and the pilot turned the plane around. The second possibility, is that the plane was hijacked either by the pilot with mental issues, or by terrorist act. The transponders would be turned off either ordered by the terrorists or by the mad pilot. I saw a Pentagon analyst say that if this was a terrorist attack, this could be dry run or a feasibility study to see if this would work in the United States.
The heading is way off course. There are two possibilities again. Either the pilot believed that he was headed back to Kuala Lumpur and was mistaken, or the course is deliberate. It doesn't much matter until point B is reached.
If the pilot is flying a damaged plane, and he believes that he is on the course back to Kuala Lumpur, he will hold his course to point C until he sees the lights of the city. Unfortunately he get to North Sumatra and there is no city. He keeps flying until the plane falls out of the sky between points C and E. If the pilot was not under coercion and sane, then he would realize that by point E that he had flown long enough to reach Kuala Lumpur and missed it. Again in the same state, he should have realized that he was not over the Malay Peninsula and might have turned south to point D, when reaching point D should have realized that he missed Kuala Lumpur. With the damaged plane, sane pilot scenario, the wreckage should be found in the orange circle, or at maximum in the pink circle or if there was a course change, in the yellow circle around C,D, and E.
The terrorist or mad pilot scenario is scarier. If there was a terrorist or if the pilot went mad, there was enough fuel in the plane to take the flight out into the deep Indian Ocean to point F and past so that the plane would never be found or not found for a long time. If the plane ditched around land, the water is relatively shallow compared to surrounding ocean. This same scenario would hold true if the plane de-pressurized killing all aboard and then continue to fly on auto-pilot like the case that killed golfer Payne Stewart.
So there you have it. If there is a reasonable explanation, I would look in the Indonesian waters off North Sumatra for the wreckage. If the loss of the plane defies rationality, if it is found, it will be somewhere off in the Indian Ocean.
Time will tell.