increasing the displacement to 4,100 tons and pushing the overall length to . Propulsion machinery consisted of two General Electric LM2500 gas turbines, which provided a combined to the single propeller shaft. Top speed was , with a range of at . Two electric auxiliary propulsors were used for close manoeuvring, with a top speed of . The standard ship's company was 184, including 15 officers, but excluding the flight crew for the embarked helicopters. The original armament for the ship consisted of a Mark 13 missile launcher configured to fire RIM-66 Standard and RGM-84 Harpoon missiles, supplemented by an OTO Melara gun and a Vulcan Phalanx point-defence system. For anti-submarine warfare, two Mark 32 torpedo tube sets were fitted; originally firing the Mark 44 torpedo, the Adelaides later carried the Mark 46 torpedoes. Up to six machine guns were carried for close-in defence, and beginning in 2005, two M2HB .50 calibre machine guns in Mini Typhoon mounts were installed when needed for Persian Gulf deployments. The sensor suite included an AN/SPS-49 air search radar, AN/SPS-55 surface search and navigation radar, SPG-60 fire control radar connected to a Mark 92 fire control system, and an AN/SQS-56 hull-mounted sonar. Two helicopters could be embarked: either two S-70B Seahawk or one Seahawk and one AS350B Squirrel. Adelaide was laid down to the Oliver Hazard Perry class' Flight I design at Todd Pacific Shipyards at Seattle on 29 July 1977, launched on 21 June 1978 by Lady Ann Synnot (wife of Chief of Naval Staff Admiral Sir Anthony Synnot), and commissioned into the Royal Australian Navy on 15 November 1980. During construction, she was identified with the United States Navy hull number FFG-17. A total of four Adelaide-class ships were constructed by Todd Pacific, with a further two built by Australian shipbuilder AMECON. Operational history After commissioning, Adelaide and Canberra remained in the United States to work up; during this time both ships were attached to the United States Navy's Destroyer Squadron 9. The frigate ran aground off Seattle in early 1981, during post-commissioning trials, but was freed with only minor damage. Following the decommissioning of the aircraft carrier in 1982 and the disbandment of fixed-wing aviation squadrons in 1984, the RAN Fleet Air Arm became focused on helicopter operations, but had minimal experience flying helicopters from small ships. To remedy this, a Bell Kiowa was embarked aboard Adelaide during 1984. Adelaide was