 During the early 1960s , India and Britain agreed upon the domestic production of the Leander @-@ class frigate . The initial helicopter deployed aboard India 's Leanders , known as the Nilgiri @-@ class , was the Aérospatiale Alouette III , however , this offered much less capability in the anti @-@ submarine role compared with the Sea King and the need for design changes was realised to allow the Sea King to be deployed upon the flight deck of the Nilgiri @-@ class , a practice pioneered by the Royal Canadian Navy using their Sikorsky CH @-@ 124 Sea Kings on similar @-@ sized frigates . It proved unfeasible to operate the Sea King from the unmodified Nilgiri @-@ class , with the last two ships of the class being fitted with an enlarged flight deck and hangar . This required removal of the ship 's Limbo anti @-@ submarine mortar . Beyond the original 1971 procurement , India chose to acquire a further six <unk> in 1974 , and three more in 1980 ; these three had been specifically modified to operate from the flight deck of the last two Nilgiris and designated as <unk> . As a follow @-@ on to the Nilgiris , India commenced development of a new frigate , based on the Leander / Nilgiri , but larger . The resultant Godavari @-@ class , also known as Project 16 , could operate two Sea Kings simultaneously . 
