 Westland Helicopters , which had a long @-@ standing licence agreement with Sikorsky Aircraft to allow it to build Sikorsky 's helicopters , extended the agreement to cover the Sikorsky SH @-@ 3 Sea King soon after the Sea King 's first flight in 1959 . Westland proceeded to independently develop the Sea King , integrating a significant proportion of components from British suppliers ; key changes include the use of a pair of Rolls @-@ Royce Gnome turboshaft engines and the implementation of an automatic flight control system . On this matter , authors Jim Thorn and Gerald Frawley stated that : " Despite appearances , Westland 's Sea King [ is a ] very different aircraft from Sikorsky 's " . Many of the differences between the Westland @-@ built Sea King and the original helicopter were as a result of differing operational doctrine . While the U.S. Navy Sea Kings were intended to be under tactical control of the carrier from which they operated , the Royal Navy intended its helicopters to be much more autonomous , capable of operating alone , or coordinating with other aircraft or surface vessels . This resulted in a different crew arrangement , with operations being controlled by an observer rather than the pilot , as well as fitting a search radar . 
