retroactively implement the upgrades in previously delivered aircraft. Main production variants F-16A/B The F-16A (single seat) and F-16B (two seat) were initially equipped with the Westinghouse AN/APG-66 pulse-doppler radar , Pratt & Whitney F100-PW-200 turbofan, rated at 14,670 lb f (64.9 kN) and 23,830 lb f (106.0 kN) with afterburner. The