In the recent years, attention has been gathered in the research field of electric airplanes (EAs), which have electric motors as a power source. EAs have many advantages including low environmental impact and safety. The flight range per charge, however, is shorter than that of conventional airplanes. This paper proposes a range extention control system (RECS) which extends the flight range of EAs by control. It is shown that the power consumption can be minimized by optimizing thrust distribution on multiple propellers with different properties. The effectiveness of the proposed method is verified by simulations and experiments.