The Royal Australian Navy ordered twelve Sea King helicopters. built by Westland at Yeovil, England, which were designated HAS.Mk.50, being an export version of the Royal Navy's HAS.Mk.2, with the addition of a ship-to-air refueling system. An Ekco AW391 search radar is fitted in a dorsal radome and four Mk.44 homing torpedoes can be carried. Two 1535 shp Gnome H. 1400-1 turboshafts and a six-bladed tail rotor power this variant. In 1991, 817 Squadron commemorated its 50th anniversary by painting one of its Sea Kings in this special livery, which incorporates the squadron badge.