<hi style=afpcap>The Sikorsky R-4 can claim to have been the first helicopter to see operational service with any of the U.S. armed forces. The XR-4 prototype was ordered in 1941, and made its first flight in January 1942 at Stratford, Connecticutt. Subsequently the XR-4 was flown to Wright Field, Ohio with several refuelling stops, thereby performing the world's first long distance, cross country helicopter flight. 30 YR-4A and YR-4B versions were ordered in 1942 for service trails, with climatic tests being conducted in Alaska and Burma. Three of these helicopters were transferred to the Coast Guard while seven more were supplied to the UK for evaluation by the RAF. The R-4B was the production version with 100 being ordered in 1943, of which 45 were exported to Britain, with a further 20 joining the Coast Guard. </hi>
