 By 1979 , the Royal Navy had ordered 56 <unk> and 21 HAS2s to meet the anti @-@ submarine requirements , these were also configured for the secondary anti @-@ ship role . The Westland Sea King was updated and adapted for numerous roles , subsequent variants include the <unk> , HAS5 and <unk> . Changes from initial production aircraft included an expansion of the cabin and upgraded engines . 
