Today in aviation history – 20th August

On 20th August 1970 was made a test flight of an American helicopter Sikorsky S-67 Blackhawk. It was an experimental construction produced by Sikorsky Aircraft Corporation. Blackhawk was two-men attack helicopter equipped with wings installed in low-wing construction. The weaponry consisted of cannons XM-140 cal. 30 mm. Production of this helicopter was connected with war in Vietnam.