Sources tell CNN it appears that Malaysia Airlines Flight 370 disappeared from military radar for about 120 nautical miles.
According to a senior official with the Malaysian government, the absence from radar means it likely dipped below an altitude of 5,000 feet.
What would have caused the drop in altitude? And how dramatic of a drop would it be for the plane to make?
CNN's Martin Savidge is in the flight simulator to demonstrate how an altitude drop would play out.