December 27, 2011: Two months ago, the U.S. MQ-1 Predator UAV fleet hit a million hours in the air. Over 20 percent of those hours were flown this year. The Predator replacement, the MQ-9 Reaper, has flown nearly 250,000 hours so far. America's large UAVs (MQ-1, MQ-1C, MQ-9, RQ-4, and RQ-170) flew some 400,000 hours this year. That's compared to 300,000 hours last year, 185,000 hours in 2009, and 151,000 hours in 2008. It took 12 years of service (1995-2007, including development) for the MQ-1 Predator alone to reach its first 250,000 hours. It took another two years (2007-2009) to fly an additional 250,000 hours (500,000 total). It took less than a year to reach another 250,000 hour milestone (Spring 2010).

So far, between the air force and CIA (a major operator of UAVs over Pakistan and other places) there are 500 MQ-1 and MQ-9s built or on order. Some 20 percent of these have been lost to accidents. Fourteen were lost that way this year. But the troops can't get enough of these aircraft overhead.

The U.S. Air Force has ordered nearly fifty MQ-9 Reaper UAVs this year. Each of the new MQ-9s will cost about $6.2 million each. The price more than doubles as sensors, fire control, and communications gear is added, this is typical with combat aircraft and that's what the air force considers the Reaper.

The air force has over 70 MQ-9s in service and the new orders will take about a year to complete. The air force wants to buy another 200 before replacing the MQ-9 with the MQ-X. The MQ-1 Predator is being replaced by the MQ-9 and the last USAF MQ-1 was built last year. The total USAF fleet of MQ-1s and MQ-9s consists of over 250 UAVs. By the end of the decade, the army and air force will have over a thousand of these large, armed, UAVs.

The MQ-1 Predator UAV has evolved into a family of three aircraft. The original Predator is a one ton aircraft that is 8.7 meters (27 feet) long with a wingspan of 15.8 meters (49 feet). It has a hard point under each wing, which usually carry one (47 kg/107 pound) Hellfire each. Each hard point can also carry a Stinger air-to-air missile. Max speed of the Predator is 215 kilometers an hour, max cruising speed is 160 kilometers an hour. Max altitude is 8,000 m (25,000 feet). Typical sorties are 12-20 hours each.

The MQ-9 Reaper is a 4.7 ton, 11.6 meters (36 foot) long aircraft with a 21.3 meters (66 foot) wingspan that looks like the MQ-1. It has six hard points and can carry 682 kg (1,500 pounds) of weapons. These include Hellfire missiles (up to eight), two Sidewinder or two AMRAAM air-to-air missiles, two Maverick missiles, two 227 kg (500 pound) smart bombs (laser or GPS guided). Max speed is 400 kilometers an hour and max endurance is 15 hours. The Reaper is considered a combat aircraft, to replace F-16s or A-10s on many missions.

The U.S. Army MQ-1C Gray Eagle weighs 1.5 tons, carries 136 kg (300 pounds) of sensors internally, and up to 227 kg of sensors or weapons externally. It has an endurance of up to 36 hours and a top speed of 270 kilometers an hour. Gray Eagle has a wingspan of 18 meters (56 feet) and is 9 meters (28 feet) long. The MQ-1C can land and take off automatically, and carry four Hellfire missiles (compared to two on the Predator).

China is trying to export UAVs nearly identical to the Predator but about 20 percent lighter. The replacement for the MQ-9 (MQ-X) is still in the design stage, although budget cuts and improved sensors (multiple cameras on one aircraft) may force the air force to just "evolve" the MQ-9. Currently this means adding electronic warfare and missile defense equipment to enable the aircraft to survive in areas where the enemy has better anti-aircraft weapons. There is also a need for better flight control software and improved ability to handle cold weather operations (as in places like Afghanistan), where wing icing is a constant problem.

The air force also wants to improve the reliability of its UAVs and reduce the loss rate (an accident causing destruction, or at least a million dollars of damage, per 100,000 flight hours). As of last year, the rate for its MQ-1 Predators was down to about 7. Although this is twice the rate of manned fighter aircraft (like the F-15 or F-16), and five times the rate of the old but very reliable B-52, it's about the same rate as single engine private aircraft (8.2).

Only a few years ago, the loss rate for the 1.1 ton MQ-1 was 30. The 4.7 ton larger MQ-9 Reaper had a loss rate of about 15 last year, after four years in service. It was a decade ago that the MQ-9 made its first flight. The Predator has been in action since the late 1990s. The design and operation of the MQ-9 learned much from the experience of the MQ-1.

Unmanned aircraft have always had a much higher loss rate, which is largely the result of not having a pilot on board and not doing all that could be done to compensate for that. Older model UAVs had much higher rates. The 1980s era RQ-2A Pioneer had an annual rate of up to 363 per 100,000 hours. Despite that, the RQ-2 proved very useful during the 1991 Gulf war.