The aircraft was powered by a total of four supercharged Armstrong Siddeley Serval III ten-cylinder radial engines, each capable of providing up to 340 hp (250 kW). This powerplant was a relatively recent development, each one basically being a pair of Armstrong Siddeley Mongoose engines joined together. These engines, which were positioned on the leading edge of the wing, were faired into the wing profile for greater aerodynamic efficiency. They were mounted upon a tubular framework attached to the forward spar of the wing, which was protected from a potential engine fire by a fire-proof bulkhead. Both of the aircraft's two fuel tanks were accommodated within the wing's leading edge, one between each pair of engines, positioned as to permit fuel to be gravity fed.