REGENERATIVE BATTERY-AUGMENTED SOARING

Some auxiliary powered sailplanes take off with a propeller turned by a battery powered motor. During flight, using technologies developed for regenerative braking of battery-powered cars, the propeller can be operated as a windmill and the motor be employed as a generator to recharge the battery. Some altitude is sacrificed during the charging, which is usually done in upcurrents; a portion (probably less than one half) of this "altitude energy" can then be utilized as desired later in the flight. Thus the pilot has an additional variable to incorporate into flight stratery, and the capability of extending the search for a safe landing site.