Photo: Snow accumulates in Little Orleans, Md.; a major storm is bringing several inches of snow and is expected to have a major impact on road and air travel along much of the East Coast over the next 24 hours, wrapping up in Maine Thursday morning - @Ginger_Zee
Lambert-St. Louis International Airport spokesman says 6 outbound flights were cancelled Tuesday morning, largely because the planes were among the 10 cancelled or diverted during overnight flight restrictions - @AP
Air travel is a form of travel in vehicles such as airplanes, helicopters, hot air balloons, blimps, gliders, hang gliding, parachuting, or anything else that can sustain flight. Use of air travel has greatly increased in recent decades - worldwide it doubled between the mid-1980s and the year 2000.