Sikorsky S-67 Blackhawk

When the Cheyenne failed to live up to expectations, Sikorsky offered an intermediate aircraft consisting of an armed version of it's S-61 (which evolved into the Sea King). Sikorsky then designed a simplified AAFSS using the maximum number of components from the S-61. The result was the Sikorsky (S-67) Blackhawk, which featured a five-bladed main rotor and tail rotor. The main wheels were retractable. It had speed brakes on the wing trailing edges, which also improved maneuverability. The Blackhawk was put through a long series of tests from 1970 to 1974, but was judged unsatisfactory by the Army. The S-67 was fitted with night vision systems, a Tactical Armament Turret (TAT-140) with a 30mm cannon, 16 130mm TOWs, and 2.75 inch rockets or Sidewinder air-to-air missiles. The S-67 established an E-1 class world speed record on December 14, 1970 by flying at 216.84 mph (249.53 knots) over a 1.86 mile (3km) course. Near the end of the test program, the Blackhawk, by substituting a ducted fan for the tail unit, reached a speed of 230 mph (264.7 knots) in a test dive in 1974. The Blackhawk was powered by two General Electric T58-GE-5 1500 shp engines.