We old pilots were drilled to know what is the closest airport of safe harbor while in cruise. Airports behind us, airports abeam us, and airports ahead of us. They’re always in our head. Always. If something happens, you don’t want to be thinking about what are you going to do–you already know what you are going to do. When I saw that left turn with a direct heading, I instinctively knew he was heading for an airport. He was taking a direct route to Palau Langkawi, a 13,000-foot airstrip with an approach over water and no obstacles. The captain did not turn back to Kuala Lampur because he knew he had 8,000-foot ridges to cross. He knew the terrain was friendlier toward Langkawi, which also was closer.
via A Startlingly Simple Theory About the Missing Malaysia Airlines Jet | WIRED.