Kaman HH-43 Huskie

The Kaman HH-43 Huskie was a compact American rescue and utility helicopter built by Kaman Aircraft and recognisable by its two intermeshing main rotors, a layout developed by the German engineer Anton Flettner, who emigrated to the United States after the Second World War and became Kaman's chief designer. Because the two rotors turn in opposite directions it needed no tail rotor. The first prototype flew on 21 April 1953, and the type was adopted by the United States Air Force, Navy and Marine Corps under the HOK, HUK and H-43 designations, with early models using piston engines and later ones a single Lycoming T53 turboshaft. The Air Force used it chiefly for crash rescue and aircraft fire fighting around air bases, and in the Vietnam War crews flew it as a search and rescue helicopter and carried out the first combat medical evacuation in March 1965. It was also exported to several countries, and examples survive in museums.