Research group has gained on the year's considerable experiences in the flight dynamic and flight mechanic, going through many numerical and experimental activities. Flight mechanic activities, aimed to aircraft performances experimental measurement and optimization, have been carried out. Other activities have been addressed to the measurement of aircraft aerodynamic derivatives during flight tests (System Identification, Parameter Estimation) with the goal to create the aircraft aerodynamic database (in linear and nonlinear range) useful for flight simulation. Remarkable activities have been carried out by Prof. Nicolosi in the flight tests and flight certification of light and ultralight aircraft, also in cooperation with Tecnam (CS-23 certification of P2006T light aircraft). The group has experience in the design, set-up and use of flight tests instrumentation (sensors and acquisition systems). Fast and reliable approaches have been tuned for the flight data post-processing such as for the performance evaluation and parameter estimation (maximum likelihood method) from flight tests. Recently activities have been performed on Tecnam light aircraft flight tests and certification. Other experimental activities concerned the Tecnam P92 ultralight flight tests for the rolling performance and ailerons efficiency estimation. Numerous flight simulation activities have been performed on several aircraft. Prof. De Marco is one of JSBSim developers, an international platform for flight dynamic equations solving, core of Flight Gear flight simulation system.