The AH-1J Sea Cobra was developed for the USMC as a twin engine variant based on a desire for improved safety and redundancy for over-water operation. Featuring the Pratt and Whitney Twinpac T400 engine (two 900-hp turboshaft engines coupled together) giving an overall increase in installed power,
it also included a new nose turret gun, with the three barrel XM197 20mm cannon, as well as other improvements. While development and production of the first 49 ordered were under way, the Marines
loaned 38 AH-1Gs from the US Army