The Sikorsky S-67 Blackhawk was a private-venture prototype attack helicopter built in 1970. The S-67 was developed from the Sikorsky SH-3 Sea King.
The single prototype manufactured crashed while performing a low-level roll maneuver - the nose dropped too close to the ground. The aircraft struck the ground and immediately burst into flames. Both pilots died from the accident, Stu Craig died on impact and Kurt Cannon died nine days later from his injuries.