Already America's most populous state by a wide margin, California is also home to vital airports for millions of monthly domestic and international fliers - including Los Angeles International Airport, which is among the busiest transit hubs on the planet. The Federal Aviation Administration's looming reductions, set to take effect in less than 24 hours, could have significant impacts on commercial flights in and out of San Francisco International Airport, Oakland San Francisco Bay Airport, San Diego International Airport, Ontario International Airport and LAX.