In the last six months, U.S. MQ-1 Predator UAVs have flown over 100,000 hours. It took ten years of service (including development) to reach the first 100,000 hours. It took another two years to reach 250,000 hours. Getting from 300,000 to 400,000 hours took only ten months. There are about a hundred Predators in service, and they are averaging about 200 flight hours a month. That's over three times as much air time as jet fighters get. Predators fly about 30 missions a day over Iraq and Afghanistan.
Predators are mainly reconnaissance aircraft, but ones that are capable to carrying out a relatively new airborne mission; surveillance (keeping an eye on one patch of ground for an extended period). Surveillance missions tie up a lot of airborne hours, but yield big results on the ground, where lots of enemy activity can be observed (especially at night). The army and marines have developed new tactics to take advantage of these new reconnaissance and surveillance capabilities. As more Predators become available, the ground troops put them right to work. So far, too many Predators are not enough.
Two years ago, the U.S. Air Force formed the first UAV Wing (the 432nd). The Wing began with six Predator and one maintenance squadrons. Each Predator squadron has at least twelve UAVs, and sometimes as many as 24. Squadrons have 400-500 personnel. Only about two thirds of those troops go overseas with the UAVs. The rest stay behind in the United States, and fly the Predators via a satellite link from several different air force bases. When in a combat zone, each Predator averages up to 200 hours in the air each month. Each aircraft flies 6-10 sorties a month, each one lasting 15-25 hours.
Air Force Wings, which are roughly the size of army brigades, are the largest units in the air force, aside from the numbered air forces (1st Air Force, 7th Air Force, and so on). There used be Air Divisions (composed of two or more Wings), but these were phased out in the 1990s.
By next year, the air force expects to have fifteen Predator squadrons, and two or more Predator Wings. During that period it is buying about a hundred MQ-1 Predators and MQ-9 Reapers. About a third of the new UAVs will be Reapers.
While the Predator was a reconnaissance aircraft that could carry weapons (two Hellfire missiles, each weighing a hundred pounds), the Reaper was designed as a combat aircraft that also does reconnaissance. The Reaper can carry over half a ton of GPS or laser guided bombs, as well as the 250 pound SDB, or Hellfire missiles. The Predators cost about $4.5 million each, while the Reaper goes for about $8.5 million (although that can go a lot higher depending on what kind of sensors you install).
The Reaper weighs about four times as much as a Predator, and carries sensors equal to those found in targeting pods like the Sniper XL or Litening, and flies at the same 20,000 foot altitude of most fighters using those pods. This makes the Reaper immune to most ground fire, and capable of seeing, and attacking, anything down there. All at one tenth of the price of a manned fighter aircraft. The air force expects to stop buying the Predator in three years, and switch over to the Reaper and MQ-1B.