Question: The Advanced Tactical Fighter (ATF) was a demonstration and validation program undertaken by the United States Air Force, including the Soviet Sukhoi Su-27, a twin-engine supermaneuverable fighter aircraft designed by Sukhoi, it was designed to complement which aircraft?
Sentence (from "Advanced Tactical Fighter"): The Advanced Tactical Fighter (ATF) was a demonstration and validation program undertaken by the United States Air Force to develop a next-generation air superiority fighter to counter emerging worldwide threats, including Soviet Sukhoi Su-27 and Mikoyan MiG-29 fighters under development in the 1980s.
Relevant evidence: Yes