Fantastic detailed RC Scale Helicopter.!! The Sikorsky H-19 Chickasaw (company model number S-55) was a multi-purpose helicopter used by the U.S. Army and USAF. It was also license-built by Westland Aircraft as the Westland Whirlwind in the United Kingdom. Development of the H-19 was initiated privately by Sikorsky without government sponsorship. The helicopter was initially designed as a testbed for several novel design concepts intended to provide greater load-carrying ability in combination with easy maintenance. The first customer was the USAF, which ordered five YH-19 aircraft for evaluation; the YH-19's first flight was on 10 November 1949. This was followed by delivery of the first YH-19 to the USAF on 16 April 1950 and delivery of the first HO4S-1 helicopter to the U.S. Navy on 31 August 1950. THANKS