AH-1s CobraThe AH-1F incorporates all Step 1 and 2 upgrades to the AH-1S. It also featured Step 3 upgrades: a head-up display, a laser rangefinder, an infrared jammer mounted above the engine exhaust, and an infrared suppressing engine exhaust system, and the M143 Air Data Subsystem (ADS). The AH-1F is also referred to as the "Modernized AH-1S", "AH-1S Modernized Cobra", or "AH-1S(MC)" prior to 1988.[85]Model 249Experimental demonstrator version fitted with the four-blade rotor system from Bell 412, an uprated engine, and experimental equipment, including Hellfire missiles credit from.TatsuTheOtaku