preparations. >> oxygen, check. instruments, check. >> in a 777 simulator, mitchell casado shows cnn's martin savidge the preflight prep. the pilot loads the route, programming the aircraft to fly to its destination. >> reporter: it's essentially step by step going to make this plane from kuala lumpur all the way to beijing. >> the plane is ready. before taking off, paul weeks sends a message home. >> the last line was, this counts as one day, so that means it's only 27 days till i see you all again. >> around 12:30 a.m., malaysian airlines flight 370 pushes back from the gate and eases toward the runway. the aircraft is cleared for takeoff. >> let's go. so the brakes are off and everything is set. >> the captain boosts the massive engines. the plane roars into the sky.