In the depths of winter, Ted Stevens Airport in Anchorage operates in the dark for up to 19 hours a day, so its state-of-the-art lighting system is vital to keep planes moving. Without it, air traffic shuts down. Follow the airport's electrician foreman and his team as they race to fix a string of 60 runway lights that have gone out. Then head to the busiest seaplane base in the world, where pilots fly more than 150 missions a day into the Alaskan wilderness, always at risk of being stranded in temperatures as low as -35 degrees.