Aeroengine manufacturers must continuously develop new high-performance engines, in terms of both specific fuel consumption and pollutant emissions. During the combustion of kerosene, CO 2 and lower amounts of SO 2 , CO, NO x and hydrocarbons are produced; those gases are directly or indirectly responsible for greenhouse effect. Large emission of NO x is produced by engines during the aircraft operation in airport. In the near future, the target in Europe for the aviation sector provides a reduction of SO% of NO x and 50% of CO 2 . For this reason, the hybrid-electric propulsion systems (HEPS) are becoming a viable alternative propulsion technology in the field of aviation, useful to guarantee a massive reduction of pollution. In the paper, the authors analyze and simulate a hybrid turbine/electric engine for a passengers regional aircraft, comparing the results in terms of pollutant and fuel consumption with the conventional thermal engine ones.