STRATFORD, USA, The American Defence Department approved the upgrading project of the Sikorsky UH-60A Black Hawk helicopters, that expects, during the next 20 years, the upgrade of about 1500 present and future aircrafts that take service for the American Army. The upgrading program will extend the Black Hawk's operative life of 25-30 years increasing its perfomances,its speed of about 15 nots and...