Malaysian Plane: What probably happened:

[zebonaut]

Despite the mainstream media over analysis of the disappearance of Flight 370 involving meteors and spy novel terrorism; here is a likely theory by a Pilot that makes sense:

This theory fits the facts.

And it's one of the most plausible yet:

Shortly after takeoff, as Malaysia 340 was flying out over the ocean, smoke began filling the cockpit, perhaps from a tire on the front landing gear that had ignited on takeoff

The flight's captain immediately did exactly what he had been trained to do: Find the closest airport and turn the plane toward it so he could land.

The closest appropriate airport was called Pulau Langkawi. It had a massive 13,000-foot runway. The captain programmed the destination into the flight computer. The auto-pilot turned the plane west and put it on a course right for the runway

The captain and co-pilot tried to find the source of the smoke and fire, but it soon filled the cockpit and overwhelmed them (a tire fire would do this). It also shorted out cockpit systems one by one, including the transponder. The pilots passed out or died.

With no one awake to instruct the auto-pilot to land, the plane kept flying on its last programmed course... right over Pulau Langkawi and out over the Indian Ocean. Eventually, 6 or 7 hours after the incident, it ran out of fuel and crashed.

No alien spaceships necessary.

[shraby]

1. Sounds logical to me.

[SheilaT]

2. But why no Mayday call?

A few days ago I did a quick search on crashed planes to find ones that did not give out a Mayday and they are remarkably few and far between.

It actually astonished me as to how quickly pilots could call Mayday and still do what they needed to do, which says a great deal about how well trained and highly skilled those people are.

However, there is a nice logic in your scenario. The information that the plane apparently kept on flying for some hours after the last contact has reminded me of the Payne Stewart crash a while back. That aircraft apparently experienced depressurization, killing everyone on board before it eventually ran out of fuel and crashed.

Given the reports that the plane at some point went to an unusually high altitude, I'm guessing another possibility is that the climb was done deliberately, the passenger cabin depressurized which would incapacitate everyone there. I can't speculate as to exactly what might have happened next, except that again, the plane may have flown until it ran out of fuel and crashed.

I don't claim any sort of probability here, just a reasonable possibility.