Hybrid electric propulsion is a promising new technology to reduce emissions and fuel consumption of an aircraft. In this study a parallel hybrid electric configuration is considered. Since electric motors supply power in the most demanding take-off and climb phases to achieve the required thrust, the turbofan can be redesigned.

It was found that the cruise thrust specific fuel consumption could be improved, even though no electric power is supplied in that phase. The hybrid-electric aircraft shows potential to save fuel over a complete mission. Most of these savings are however achieved due to fully electric taxiing. The weight of the electrical system largely offsets the efficiency improvements of the gas turbine during flight. Given that optimistic technology levels are used for these results, parallel hybrid electric propulsion is not expected to be used in the coming decade on short haul flights with narrow-body aircraft.