The YF-12 was developed in the 1960s as a high-altitude, Mach 3 interceptor to defend against supersonic bombers. Based on the A-12 reconnaissance aircraft, the YF-12A became the forerunner of the
Lockheed YF-12A – AviationMuseum
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National Museum of the USAF : r/aviation
Lockheed YF-12A > National Museum of the United States Air Force
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