Mil Mi-26 (NATO reporting name: "Halo") is the largest and most powerful helicopter ever to enter serial production. Designed in the Soviet Union during the 1970s, it was built to transport massive cargo to remote areas unreachable by fixed-wing aircraft. Key Performance & Specs Payload Capacity: It can lift up to 20 metric tons (44,000 lbs) internally or on an external sling. Dimensions: It measures roughly 40 meters (131 ft) in length—comparable to a Boeing 737. Powerplant: Driven by two Lotar