Elbit Systems has unveiled  its new R902 (W) engine designed to improve the performance of its Hermes 450 unmanned air vehicle. The R902 engine ("W" denotes "wide") is based on "Wankel" technology, which Elbit says is ideal for tactical UAVs due the power-to-weight and -size ratios it offers.

The "W" engine includes a larger combustion compartment than its predecessors, derived from an increase in the width of the Wankel
engine block. The new engine weighs approximately 40kg and delivers over 70bhp.

According to the Israeli company the power-to-weight ratio of this engine is considered the best among internal combustion engines (piston and Wankel engines), thus setting a new standard for UAV engines. Turbojet engines offer a high power-to-weight ratio but consume more fuel.

The new engine increases the endurance of the Hermes 450 to more than 20h. It is equipped with an electronic fuel control and a starter-alternator option for airborne ignition.

Source: FlightGlobal.com