Over the last two years, the United States has sent over the largest helicopter force ever seen in Afghanistan. Most of the aircraft in Afghanistan are helicopters, and most of these belong to the U.S. Army. By itself, U.S. Army aviation would be one of the largest air forces in the world. The U.S. Army has 20 CABs (Combat Aviation Brigades). Twelve are active duty units, and eight are from the reserves. Another active duty CAB is being formed. A CAB contains, on average, 2,700 troops and 120 aircraft (nearly all OH-58 scout, AH-64 gunship and UH-60 and CH-47 transport helicopters). The CABs sent to Afghanistan are worked very hard. In Afghanistan, American helicopter pilots fly about 63 hours a month each. This is five times the number of hours they would fly back at their home base. The CABs are spending more time overseas than the (ground) combat brigades.
Even with the withdrawal of troops from Iraq, a record number of CABs are staying overseas. That's because helicopters are more vital, and numerous, in Afghanistan than in Iraq. There are only about 60 percent as many U.S. troops in Afghanistan, compared to peak strength in Iraq. Thus from last year to 2014, about a third of the CABs will be overseas at one time. That's fifty percent more than in the last few years. To help support that, two additional CABs were formed in the last year. One was assembled from existing helicopters not assigned to CABs, and is already in service. The other one is being built from scratch, and will be ready by the end of the year. Forming these two new CABs cost $6.6 billion. In addition to this, hundreds of heavy (1.5 ton Sky Warrior) UAVs are being added to the CABs. The army is also reorganizing the CABs, which currently come in three types; light, medium and heavy, into "Full Spectrum" units that contain a mix of different helicopter types.