Today in aviation history – 22nd December

On 22nd December 1964 there was made a test flight of SR-71 Blackbird. This two-engine delta mid-wing was used in strategy long distance intelligence. Thanks to maximum speed of 3.5 Ma, true air speed of 3.2 Ma and maximum height of 36000 m was very difficult to detect and intercept. The total production run of SR-71 Blackbird was 32 and they were used until the end of 1980’s when they were withdrew because of the working costs.