Turbofan Trends for Short Haul

After a general indication of the noise problem the relation between conventional and STOL systems are broadly reviewed and their requirements as regards the powerplant are discussed. Some of the associated technical challenges are then considered. These include variable pitch fans, reduction gears, thrust reversal and the environment, (noise and pollution). It is shown that the development of a quiet, clean propulsion engine is perhaps the most important and pressing single task for the powerplant constructor to attack.