YUMA PROVING GROUND, Az.-- The UH-1 Iroquois helicopter, better known as the "Huey," has been retired from Army service after a distinguished career spanning six decades.Four of the Army's final eleven served until the very last at U.S. Army Yuma Proving Ground. Their last YPG flight occurred on October 20th, with YPG commander Col. Randy Murray and Yuma Test Center commander Lt. Col. James DeBoer piloting two of the proving ground's four Hueys.Two of the aircraft ferried passengers on a ceremonial pass above YPG's three cantonment areas, while the other two carried parachutists from the Airborne Test Force for a final parachute jump onto Philips drop zone as spectators from YPG watched from a nearby shade structure.An iconic airframe of the Vietnam War, the Huey has served as workhorse of the proving ground's air fleet for decades. The same airframe that supported testing of the Global Positioning System at YPG in the late 1970s was still used for state-of-the-art testing up to the first weeks of October.Each of the final four Hueys has been remarkably well maintained and the platform's retirement is bittersweet to YPG pilots and military aircraft enthusiasts throughout the country, particularly those who served missions aboard them during the Vietnam era."This is the first aircraft I flew when I started flying in 1975," said Ralph Arnold, who has accumulated over 4,000 hours flying UH-1s. "I was kind of hoping it would be the last one I flew. There's nothing like flying a Huey: the sound of a rotor blade popping on a Huey is quite distinctive.""When we got out of flight school in our generation, this was a modern aircraft," added Gerald Fijalka, a pilot with 38 years of experience. "It's a wonderful aircraft and a lot of fun to fly, but its day has come."With capable maintenance personnel and a dry desert climate, YPG has often been the final working home of venerable military equipment. From Korean War-era M101 howitzers to the Vietnam era O-2 Skymaster observation airplane, a variety of rugged platforms have had productive second lives supporting YPG's test mission long after having been eclipsed on the battlefield.Eventually, however, a system that no longer has an Army-wide parts system or support structure must be phased out: It happened to the O-2 aircraft nearly seven years ago, and now the UH-1 has joined the list. The arrival of UH-60 Black Hawks at Laguna Army Airfield last year heralded the ultimate end of the Huey's career at the proving ground."I'm sorry to see them go," said Arnold. "They served our mission here very, very well. They are easily configurable to the different test programs we support. The Blackhawk is a very capable aircraft, but not as easily configurable."The purpose of YPG's helicopters- supporting tests- means modifications to the standard airframe are necessary to meet the mission. Each modification requires airworthiness evaluation and releases to ensure the aircraft functions safely, a time-consuming process. From specialized equipment racks inside the airframe to camera and sensor mounts on the exterior, YPG airfield personnel over the years made more than 50 different modifications to various Hueys in the fleet.The final flight of the Hueys also brought out fond memories from Soldiers who conducted parachute jumps from the airframe."I was supposed to be on leave, but I signed back in just so I could be a part of this," said Chief Warrant Officer 3 Brian Perinon, chief of YPG's Airborne Test Force. "I wouldn't let my team go out on this without my being involved."Perinon recalled jumping from a Huey for the first time at Fort Lee in his earliest days in Army Airborne."It was the best jump ever," Perinon. "You get to sit on the edge, your feet are dangling, it seems like you're going to hit the skid the first time you ever do it and you have that anxiety going. Then you get off, and it is the best feeling ever--you want to do it again and again and again."The Hueys are departing YPG, but not flying off into the sunset. All four of the aircraft will have active retirements after distribution by the Defense Logistics Agency's Law Enforcement Support Office to police agencies in places like Orange County, California and Baton Rouge, Louisiana.