December31, 2006: The U.S. Army is still buying AH-64 Apache helicopter gunships, having just received the 501st one. The latest version of the UH-60 Blackhawk is now in production, and the army will buy 1,200 of them, to replace older, 1980s, models. There is also a new scout helicopter, the ARH-70, and 368 of those are being bought, along with 322 UH-72As, to replace UH-1s in reserve units. Many of these purchases will take up to a decade to complete. But the army will be buying 150-200 aircraft a year over the next six years. In addition, over 1,600 helicopters are being refurbished as they are returned from service in Iraq and Afghanistan. Army aircraft have flown some 250,000 combat hours annually in the last four years. The U.S. Army has the largest fleet of combat helicopters (over 4,000) in the world. Add several hundred fixed wing aircraft, and the U.S. Army has one of the largest air forces in the world. Outside the United States, only China's is larger.