HYBRID ELECTRIC SYSTEMS FOR ROTORCRAFT

A hybrid electric system for a rotorcraft can include a first thermal engine (103a), a second thermal engine (103b), and an electrical machine (105). The first thermal engine (103a) can be sized to produce a maximum first thermal engine power that is below a one-or-more-engine-inoperative (OEI) requirement power and the second thermal engine (103b) can be sized to produce a maximum second thermal engine power that is below the OEI requirement power. The electrical machine (105) can be sized to provide at least a remaining power needed to reach the OEI requirement power in an OEI state.