Following the GCA-2A Helidyne compound helicopter variant, the GCA-2 was developed further as the more conventional GCA-2C, capable of carrying three litters. According to the Gyrodyne Helicopter Historical Foundation, this airframe, which has been preserved at the Cradle of Aviation Museum, was still the rebuilt original GCA-2 prototype N74101, and thus probably the original Bendix J prototype. First flight of the GCA-2C on 25 April 1952. The photo was published in January 1953 when flight testing under a US Navy contract was complete. This took place at Flowerfield, Long Island, where the Gyrodyne company moved in 1951. Photo from: National Museum of the US Navy

In 1946, the Gyrodyne company acquired rights to the Bendix Model J and developed it into the GCA-2. N74101 was reportedly the same airframe as the Bendix J prototype, N74102. The aircraft was reworked again in 1949 as the GCA-2A Helidyne compound helicopter with auxiliary engines on outriggers. Testing took place at small Fitzmaurice Field on Long Island. Photo from: Vertical Flight Society