Lockheed YF-12 Blackbird Model in the 10- by 10-Foot Supersonic Wind Tunnel

Robert Cubbison examines a model of the Lockheed YF-12 Blackbird in the test section of the 10- by 10-Foot Supersonic Wind Tunnel at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The YF-12 was an experimental fighter version of Lockheed’s A-12 reconnaissance aircraft which had been developed into the renowned SR-71 Blackbird. NASA possessed two YF-12s at its Dryden Flight Research Center which could be used by researchers at all the NASA centers. During its nine-year life, the Dryden’s YF-12 research program logged 297 flights with approximately 450 flight hours. Lewis researchers were studying the YF-12’s inlet airflow in the 10- by 10-foot wind tunnel in late 1977. The advanced supersonic cruise aircraft of the time used mixed-compression inlets. These types of inlets were prone to flameout during atmospheric disturbances. Researchers at Lewis and Dryden developed a program to study these flameouts by artificially introducing flow disturbances. Testing at Dryden with a specially-equipped YF-12 aircraft yielded limited results. Lewis’ tests in the 10- by 10 were unsuccessful at inducing upstream disturbances. The researchers used two methods—a falling plate and a servo-driven wing.