The USAF developed the HH-3E 'Jolly Green Giant' to perform combat search and rescue (CSAR) missions to recover downed Airmen during the SE Asia War. The HH-3E was a highly modified version of the CH-3 transport helicopter, being the first air-refuelable helicopter and incorporating armour plating, defensive armament, self-sealing fuel tanks, a water-tight hull and a rescue hoist. This particular aircraft has earned her retirement at the National Museum of the USAF after long and distinguished service in Vietnam.