>> the captain boosts the massive engines. the plane roars into the sky. its altimeter tracking its climb through 5,000 feet, then 10,000 feet. now airborne, air traffic controllers pick up the flight. >> they're going to see you on their radar because you've got a squawk code in your transponder which basically turns your simple radar return into something that has a lot of information on it. it includes the flight number and the speed and the altitude. >> coming up to 17,000 feet. >> this is malaysia here, and this is vietnam here. there's cambodia on the left side. >> as the plane reaches its cruising altitude of 35,000 feet, the pilots can relax a little. so can the passengers like paul weeks and philip wood. it's 1:19 in the morning. and a voice from the cockpit addresses air traffic control