As designed, the main armament for the frigate is a 5-inch 54 calibre Mark 45 gun, supplemented by an eight-cell Mark 41 vertical launch system (for RIM-7 Sea Sparrow or RIM-162 Evolved Sea Sparrow missiles), two machine guns, and two Mark 32 triple torpedo tube sets (initially firing Mark 46 torpedoes, but later upgraded to use the MU90 Impact torpedo). They were also designed for but not with a close-in weapons system (two Mini Typhoons fitted when required from 2005 onwards), two quad-canister Harpoon anti-ship missile launchers (which were installed across the RAN vessels from 2005 onwards), and a second Mark 41 launcher (which has not been added). The Australian "Anzac"s use a Sikorsky S-70B-2 Seahawk helicopter; plans to replace them with Kaman SH-2G Super Seasprites were cancelled in 2008 due to ongoing problems.