The AH-64 Apache is a four-blade, twin-turboshaft attack helicopter, developed for the United States Army as a successor to the AH-1 Cobra, to meet the advanced combat needs of the late 20th century. It was designed to be a lethal, robust, and survivable aircraft, capable of performing multiple missions, especially the anti-armor attack role. | Interesting Engineering

AH-64 Apache: US Army's Ultimate Attack Helicopter