 Two prototypes were built, one with a P&WC T400-CP-400 Twin Pac dual turboshaft engine system much like that used on the AH-1J, but with a stronger drivetrain allowing operation at full 1,800 shp (1,340 kW) power, and the other with a single Lycoming T55-L-7C turboshaft engine rated at 2,000 shp (1,490 kW).The twin-engine KingCobra first flew on 10 September 1971.It looked much like an AH-1J, except for a longer and distinctive "buzzard beak" nose and a ventral fin like that on the original Model 209 demonstrator.