For what it’s worth: Malaysia 370, Day 10: One Fanciful Hypothesis, and Another That Begins to Make Sense - James Fallows - the Atlantic

2) The Pulau Langkawi possibility. Chris Goodfellow, an experienced pilot, offers via Google+ a very different sort of explanation. Far from carrying out an elaborate scheme, he says, the pilots may have been caught by surprise by an inflight fire, a major systems failure, or some other genuine emergency. At that point they called on the reflex nearly all pilots develop: the constantly updated awareness of where the nearest airport is, if they should suddenly need to get back to the ground. As he puts it:

We old pilots were always drilled to always know the closest airport of safe harbor while in cruise. Airports behind us, airports abeam us and airports ahead of us. Always in our head. Always. Because if something happens you don’t want to be thinking what are you going to do - you already know what you are going to do.

When trouble arose, Goodfellow says, the pilots headed for what they knew to be the nearest very long runway, with an unobstructed over-water approach, on the Malaysian island of Pulau Langkawi. (Pulau means “island.”) Here’s the Google Earth idea of how the Langkawi runway might look in daylight, although the plane was of course approaching at night. That runway is 13,000 feet long — enormous.