In the wake of the MH370 plane crash, the airlines have been scrambling to keep their pilots safe.
They have been training their pilots, and the Federal Aviation Administration has been beefing up its enforcement of the National Transportation Safety Board’s rules on air travel.
The agency has said it will expand its monitoring of flight paths in the wake.
But that’s not going to solve the mystery of what happened.
Here’s what you need to know about how the plane went down.