The latest version (AF-3) of the RQ-4A Global Hawk strategic UAV (Unmanned Aerial Vehicle), made its first flight this month. The AF-3 contains a number of improvements and modifications, mainly having to do with making the aircraft more reliable. The air force is planning to produce 51 RQ-4s, including two for the U.S. Navy. The AF-3s are the last of the A version. The RQ-4B version is about to start construction. The B version is larger (wingspan is 15 feet larger, at 131 feet, and its four feet longer at 48 feet) and can carry an additional two tons of equipment. To support that, theres a new generator that produces 150 percent more electrical power. The first three RQ-4Bs wont enter service until 2006. The A version contained such a powerful array of sensors that it was like have a low flying spy satellite that, more importantly, could just circle an area. The problem with spy satellites is that they are in orbit, and rapidly pass by any area they are over. Thats why spy satellites have such powerful cameras and other sensors. The B model of Global Hawk will be even more capable of finding enemy activity in any weather or time of day.

Ten RQ-4As have been built so far, but three have been lost in action. Only two a year will be produced until 2009. After that production will go to at least four a year. The last loss was in late 2001 over Afghanistan, and the remaining UAVs were grounded for three months until the problems could be discovered and fixed. The RQ-4 was still in development on September 11, 2001, but was rushed into action. The first production RQ-4A was not delivered until August, 2003. 

Although the RQ-4 can stay in the air for up to 42 hours, all of them have only amassed about 4,000 flight hours. But most of those 4,000 hours, which were originally planned to involve testing of a new aircraft, were instead used to perform combat missions. Global Hawk also got to fly under difficult conditions, something an aircraft still being developed, would not do. So in the next few years, RQ-4s will be used much more frequently, and with much lower risk of being lost to accidents or equipment failure. But you wont hear much about it for, after all, Global Hawk is an intelligence collection aircraft, and intelligence work is best done in the shadows.