Long-suffering residents of the entry lanes of airports can still remember the noisy soot flingers of the first generation of jets. There are worlds between the humming of a modern airliner and the deafening noise of former airliners. The noise pollution in the area of the airports today amounts to a quarter of the values of 30 years ago. Decisive for this progress was the development of new engines. However, the potential in the construction of aircraft engines is far from exhausted: "In 15 years, the engines will be 15 to 20 percent more economical and 50 percent quieter, " promises Odilo Mühling of MTU Aero Engines in Munich. The hope for this is the so-called geared fan - the rotor visible in the front of the turbine. He is responsible for the thrust. In today's engines fan and turbine are connected by a rigid shaft. With the geared fan, a reduction gear should ensure that both components work optimally. Such an engine has now been developed by MTU together with engine manufacturer Pratt & Whitney and is already under test as ATFI (Advanced Technology Fan Integrator). With the market launch of the geared fan, the manufacturer expects in about five years.