The Australian built version of the Bristol Beaufighter entered service with the RAAF in 1944. The Beaufighter 21 had a Sperry autopilot in the nose which accounted for the distinctive hump and 0.5' guns in the wing. The Beaufighter 21 was based on the British TFX but lacked the ability to carry a torpedo. The Beaufighter 21 was used by the RAAF against the Japanese who respected the Beaufighter enough to give it the nickname 'whispering death' on account of the quietness of the Bristol Hercuules engines.