Aeromodeling is an exciting hobby.Jet-powered models are sophisticated aircraft.Aeromodels can even perform aerobatics in the sky!Radio-controlled airplanes come in all shapes and sizes: from the Mini Flyer-plane with a wingspan of 9 inches (23 centimeters), to the huge passenger jet models with a 29  1/2 -foot (9-meter) wingspan.At these competitions, f liers  usually do a series of actions with their planes, including launchings, landings, and doing maneuvers in the air.Jet models alwaysattract large crowds at aeromodeling competitions.They no longer f ly planes that are attached to two cables and that f ly in circles around them.Nowadays, with the advances in technology, the big thing is radio-controlled airplanes.These models f ly like real aircraft and are an aeromodeler's ultimate dream.These jet models can travel at speeds of 236 miles (380 kilometers)  per hour--that's more than the top speed of a Formula 1 race car.Most people no longer f ly the old elastic-propelled planes.People control the movement of the planes through radio signals.There are different methods of propulsion, or ways to power the planes.In the United States, for example, the Academy of Model Aeronautics has more than 170,000 members in 250 model airplane clubs.They all have one common interest--the love of f lying small-sized airplanes.The price of the airplanes varies from $30 to several thousand dollars.These range from electric motors to expensive jet turbines.Their engines sound like those of  full-size jet planes.Aeromodeling is a popular hobby all over the world.