The de Havilland Hornet bore a family resemblance to the larger Mosquito, but it was an entirely fresh design albeit one that drew extensively upon experiences from, and the design of, the Mosquito. It was powered by a pair of highly developed Rolls-Royce Merlin engines, producing each, which drove de Havilland Propellers four-bladed propellers. According to aviation author P.J. Birtles, the efficiency and power of this configuration gave the Hornet "a higher performance than any other propeller driven aircraft". The Hornet's principal armament was four short-barrelled 20 mm (.79 in) Hispano V cannons, while other typical weapon loads included various rockets and bombs.